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Gui M. Effect of humic acid on aerobic denitrification by Achromobacter sp. strain GAD-3. J Biosci Bioeng 2024:S1389-1723(24)00187-7. [PMID: 39030116 DOI: 10.1016/j.jbiosc.2024.06.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Revised: 06/15/2024] [Accepted: 06/20/2024] [Indexed: 07/21/2024]
Abstract
Humic acid (HA), a common natural organic matter, could affect conventional anoxic denitrification. Aim of this study was to investigate effect of HA on the process of aerobic denitrification in Achromobacter sp. GAD-3, an aerobic denitrifying strain. The findings demonstrated that an increase in HA concentrations (≥5 mg L-1) promoted the aerobic denitrification process (excluding N2O reduction), manifesting as higher rates of nitrate removal (6.67-11.1 mg L-1 h-1) and lower levels of nitrite accumulation (30.2-20.7 mg L-1). This was attributed to the increased electron transfer activities and denitrifying reductase activities (including NAR, NIR and NOR) facilitated by HA. Accordingly, the expression of denitrification genes such as napA, cnorB, and nirS was enhanced by HA. Nonetheless, the nosZ gene and N2OR activity underwent suppression by HA, which was accountable for N2O emission. It is crucial to understand the HA mechanism towards aerobic denitrifiers for wastewater treatment plants to enhance nitrogen removal.
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Affiliation(s)
- Mengyao Gui
- School of Resources and Environment, Nanchang University, Nanchang 330031, China; Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, Nanchang 330031, China.
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Dai W, Xie C, Xiao Y, Ma Y, Ding Y, Song Z, Wang Y, Jiao C, Zheng L, Zhang Z, He X. Bacterial Susceptibility to Ceria Nanoparticles: The Critical Role of Surrounding Molecules. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:12390-12399. [PMID: 38963915 DOI: 10.1021/acs.est.4c02396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/06/2024]
Abstract
Investigating the ternary relationship among nanoparticles (NPs), their immediate molecular environment, and test organisms rather than the direct interaction between pristine NPs and test organisms has been thrust into the mainstream of nanotoxicological research. Diverging from previous work that predominantly centered on surrounding molecules affecting the toxicity of NPs by modulating their nanoproperties, this study has unveiled a novel dimension: surrounding molecules altering bacterial susceptibility to NPs, consequently impacting the outcomes of nanobio interaction. The study found that adding nitrate as the surrounding molecules could alter bacterial respiratory pathways, resulting in an enhanced reduction of ceria NPs (nanoceria) on the bacterial surfaces. This, in turn, increased the ion-specific toxicity originating from the release of Ce3+ ions at the nanobio interface. Further transcriptome analysis revealed more mechanistic details underlying the nitrate-induced changes in the bacterial energy metabolism and subsequent toxicity patterns. These findings offer a new perspective for the deconstruction of nanobio interactions and contribute to a more comprehensive understanding of NPs' environmental fate and ecotoxicity.
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Affiliation(s)
- Wanqin Dai
- CAS Key Lab for Biomedical Effects of Nanomaterials and Nanosafety, CAS-HKU Joint Laboratory of Metallomics on Health & Environment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
- School of Physical Sciences, University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Changjian Xie
- CAS Key Lab for Biomedical Effects of Nanomaterials and Nanosafety, CAS-HKU Joint Laboratory of Metallomics on Health & Environment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
- School of Physical Sciences, University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Yong Xiao
- CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Yuhui Ma
- CAS Key Lab for Biomedical Effects of Nanomaterials and Nanosafety, CAS-HKU Joint Laboratory of Metallomics on Health & Environment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - Yayun Ding
- CAS Key Lab for Biomedical Effects of Nanomaterials and Nanosafety, CAS-HKU Joint Laboratory of Metallomics on Health & Environment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - Zhuda Song
- CAS Key Lab for Biomedical Effects of Nanomaterials and Nanosafety, CAS-HKU Joint Laboratory of Metallomics on Health & Environment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
- School of Physical Sciences, University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Yun Wang
- CAS Key Lab for Biomedical Effects of Nanomaterials and Nanosafety, CAS-HKU Joint Laboratory of Metallomics on Health & Environment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
- School of Physical Sciences, University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Chunlei Jiao
- Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
| | - Lirong Zheng
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - Zhiyong Zhang
- CAS Key Lab for Biomedical Effects of Nanomaterials and Nanosafety, CAS-HKU Joint Laboratory of Metallomics on Health & Environment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
- School of Physical Sciences, University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Xiao He
- CAS Key Lab for Biomedical Effects of Nanomaterials and Nanosafety, CAS-HKU Joint Laboratory of Metallomics on Health & Environment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
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Fan K, Wang F, Xu X, Shi J, Wang W, Xing D, Ren N, Lee DJ, Chen C. Enterobacter sp. HIT-SHJ4 isolated from wetland with carbon, nitrogen and sulfur co-metabolism and its implication for bioremediation. ENVIRONMENTAL RESEARCH 2024; 260:119593. [PMID: 39002634 DOI: 10.1016/j.envres.2024.119593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Revised: 07/04/2024] [Accepted: 07/09/2024] [Indexed: 07/15/2024]
Abstract
Both autotrophic and heterotrophic denitrification are known as important bioprocesses of microbe-mediated nitrogen cycle in natural ecosystems. Actually, mixotrophic denitrification co-driven by organic matter and reduced sulfur substances are also common, especially in hypoxic environments such as estuarine sediments. However, carbon, nitrogen and sulfur co-metabolism during mixotrophic denitrification in natural water ecosystems has rarely been reported in detail. Therefore, this study investigated the co-metabolism of carbon, nitrogen and sulfur using samples collected from four distinct natural water ecosystems. Results demonstrated that samples from various sources all exhibited the ability for co-metabolism of carbon, nitrogen and sulfur. Microbial community analysis showed that Pseudomonas and Paracoccus were dominant bacteria ranging from 65.6% to 75.5% in mixotrophic environment. Enterobacter sp. HIT-SHJ4, a mixotrophic denitrifying strain which owned the capacity for co-metabolism of carbon, nitrogen and sulfur, was isolated and reported here for the first time. The strain preferred methanol as its carbon source and demonstrated remarkable efficiency for removing sulfide and nitrate with below 100 mg/L sulfide. Under weak acid conditions (pH 6.5-7.0), it exhibited enhanced capability in converting sulfide to elemental sulfur. Its bioactivity was evident within a temperature from 25 °C to 40 °C and C/N ratios from 0.75 to 3. This study confirmed the widespread presence of microbial-mediated synergistic carbon, nitrogen and sulfur metabolism in natural aquatic ecosystems. HIT-SHJ4 emerges as a novel strain, shedding light on carbon, nitrogen and sulfur co-metabolism in natural water bodies. Furthermore, it also serves as a promising candidate microorganism for in-situ ecological remediation, particularly in dealing with contamination posed by nitrate, sulfide, and organic matter.
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Affiliation(s)
- Kaili Fan
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province, 150090, China
| | - Fei Wang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province, 150090, China
| | - Xijun Xu
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province, 150090, China
| | - Jia Shi
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province, 150090, China
| | - Wei Wang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province, 150090, China.
| | - Defeng Xing
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province, 150090, China
| | - Nanqi Ren
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province, 150090, China
| | - Duu-Jong Lee
- Department of Mechanical Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China; Department of Chemical Engineering, National Taiwan University, Taipei, 106, Taiwan
| | - Chuan Chen
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province, 150090, China.
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Murali R, Pace LA, Sanford RA, Ward LM, Lynes MM, Hatzenpichler R, Lingappa UF, Fischer WW, Gennis RB, Hemp J. Diversity and evolution of nitric oxide reduction in bacteria and archaea. Proc Natl Acad Sci U S A 2024; 121:e2316422121. [PMID: 38900790 PMCID: PMC11214002 DOI: 10.1073/pnas.2316422121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 04/24/2024] [Indexed: 06/22/2024] Open
Abstract
Nitrous oxide is a potent greenhouse gas whose production is catalyzed by nitric oxide reductase (NOR) members of the heme-copper oxidoreductase (HCO) enzyme superfamily. We identified several previously uncharacterized HCO families, four of which (eNOR, sNOR, gNOR, and nNOR) appear to perform NO reduction. These families have novel active-site structures and several have conserved proton channels, suggesting that they might be able to couple NO reduction to energy conservation. We isolated and biochemically characterized a member of the eNOR family from the bacterium Rhodothermus marinus and found that it performs NO reduction. These recently identified NORs exhibited broad phylogenetic and environmental distributions, greatly expanding the diversity of microbes in nature capable of NO reduction. Phylogenetic analyses further demonstrated that NORs evolved multiple times independently from oxygen reductases, supporting the view that complete denitrification evolved after aerobic respiration.
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Affiliation(s)
- Ranjani Murali
- Department of Biochemistry, University of Illinois, Urbana-Champaign, Urbana, IL61801
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA91125
- School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV89154
| | - Laura A. Pace
- Department of Biochemistry, University of Illinois, Urbana-Champaign, Urbana, IL61801
- meliora.bio, Salt Lake City, UT84103
| | - Robert A. Sanford
- Department of Earth Science and Environmental Change, University of Illinois at Urbana-Champaign, Urbana, IL61801
| | - L. M. Ward
- Department of Geosciences, Smith College, Northampton, MA01063
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA91125
| | - Mackenzie M. Lynes
- Department of Chemistry and Biochemistry, Thermal Biology Institute, Montana State University, Bozeman, MT59717
- Center for Biofilm Enginering, Montana State University, Bozeman, MT59717
| | - Roland Hatzenpichler
- Department of Chemistry and Biochemistry, Thermal Biology Institute, Montana State University, Bozeman, MT59717
- Center for Biofilm Enginering, Montana State University, Bozeman, MT59717
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT59717
| | - Usha F. Lingappa
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA91125
- Department of Plant and Microbial Biology, University of California, Berkeley, CA94720
| | - Woodward W. Fischer
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA91125
| | - Robert B. Gennis
- Department of Biochemistry, University of Illinois, Urbana-Champaign, Urbana, IL61801
| | - James Hemp
- meliora.bio, Salt Lake City, UT84103
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA91125
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Martinez A, Dijkstra P, Megonigal P, Hungate BA. Microbial central carbon metabolism in a tidal freshwater marsh and an upland mixed conifer soil under oxic and anoxic conditions. Appl Environ Microbiol 2024; 90:e0072424. [PMID: 38771053 PMCID: PMC11218644 DOI: 10.1128/aem.00724-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Accepted: 04/22/2024] [Indexed: 05/22/2024] Open
Abstract
The central carbon (C) metabolic network is responsible for most of the production of energy and biosynthesis in microorganisms and is therefore key to a mechanistic understanding of microbial life in soil communities. Many upland soil communities have shown a relatively high C flux through the pentose phosphate (PP) or the Entner-Doudoroff (ED) pathway, thought to be related to oxidative damage control. We tested the hypothesis that the metabolic organization of the central C metabolic network differed between two ecosystems, an anoxic marsh soil and oxic upland soil, and would be affected by altering oxygen concentrations. We expected there to be high PP/ED pathway activity under high oxygen concentrations and in oxic soils and low PP/ED activity in reduced oxygen concentrations and in marsh soil. Although we found high PP/ED activity in the upland soil and low activity in the marsh soil, lowering the oxygen concentration for the upland soil did not reduce the relative PP/ED pathway activity as hypothesized, nor did increasing the oxygen concentration in the marsh soil increase the PP/ED pathway activity. We speculate that the high PP/ED activity in the upland soil, even when exposed to low oxygen concentrations, was related to a high demand for NADPH for biosynthesis, thus reflecting higher microbial growth rates in C-rich soils than in C-poor sediments. Further studies are needed to explain the observed metabolic diversity among soil ecosystems and determine whether it is related to microbial growth rates.IMPORTANCEWe observed that the organization of the central carbon (C) metabolic processes differed between oxic and anoxic soil. However, we also found that the pentose phosphate pathway/Entner-Doudoroff (PP/ED) pathway activity remained high after reducing the oxygen concentration for the upland soil and did not increase in response to an increase in oxygen concentration in the marsh soil. These observations contradicted the hypothesis that oxidative stress is a main driver for high PP/ED activity in soil communities. We suggest that the high PP/ED activity and NADPH production reflect higher anabolic activities and growth rates in the upland soil compared to the anaerobic marsh soil. A greater understanding of the molecular and biochemical processes in soil communities is needed to develop a mechanistic perspective on microbial activities and their relationship to soil C and nutrient cycling. Such an increased mechanistic perspective is ecologically relevant, given that the central carbon metabolic network is intimately tied to the energy metabolism of microbes, the efficiency of new microbial biomass production, and soil organic matter formation.
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Affiliation(s)
- Ayla Martinez
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, USA
| | - Paul Dijkstra
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, USA
- Ecosystem Science and Society (ECOSS), Northern Arizona University, Flagstaff, Arizona, USA
| | | | - Bruce A. Hungate
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, USA
- Ecosystem Science and Society (ECOSS), Northern Arizona University, Flagstaff, Arizona, USA
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Zhou J, Yang L, Li X, Dai B, He J, Wu C, Pang S, Xia S, Rittmann BE. Biogenic Palladium Improved Perchlorate Reduction during Nitrate Co-Reduction by Diverting Electron Flow in a Hydrogenotrophic Biofilm. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:10644-10651. [PMID: 38832916 DOI: 10.1021/acs.est.4c01496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2024]
Abstract
Microbial reduction of perchlorate (ClO4-) is emerging as a cost-effective strategy for groundwater remediation. However, the effectiveness of perchlorate reduction can be suppressed by the common co-contamination of nitrate (NO3-). We propose a means to overcome the limitation of ClO4- reduction: depositing palladium nanoparticles (Pd0NPs) within the matrix of a hydrogenotrophic biofilm. Two H2-based membrane biofilm reactors (MBfRs) were operated in parallel in long-term continuous and batch modes: one system had only a biofilm (bio-MBfR), while the other incorporated biogenic Pd0NPs in the biofilm matrix (bioPd-MBfR). For long-term co-reduction, bioPd-MBfR had a distinct advantage of oxyanion reduction fluxes, and it particularly alleviated the competitive advantage of NO3- reduction over ClO4- reduction. Batch tests also demonstrated that bioPd-MBfR gave more rapid reduction rates for ClO4- and ClO3- compared to those of bio-MBfR. Both biofilm communities were dominated by bacteria known to be perchlorate and nitrate reducers. Functional-gene abundances reflecting the intracellular electron flow from H2 to NADH to the reductases were supplanted by extracellular electron flow with the addition of Pd0NPs.
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Affiliation(s)
- Jingzhou Zhou
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Lin Yang
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Xiaodi Li
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Ben Dai
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Junxia He
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Chengyang Wu
- School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai 200093, China
| | - Si Pang
- Eco-Environmental Protection Research Institute, Shanghai Academy of Agricultural Science, Shanghai 201403, China
| | - Siqing Xia
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Bruce E Rittmann
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, Tempe, Arizona 85287-5701, United States
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Cerda Á, Rodríguez C, González M, González H, Serrano J, Leiva E. Feammox bacterial biofilm formation in HFMB. CHEMOSPHERE 2024; 358:142072. [PMID: 38657691 DOI: 10.1016/j.chemosphere.2024.142072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 04/08/2024] [Accepted: 04/16/2024] [Indexed: 04/26/2024]
Abstract
Nitrogen pollution has been increasing with the development of industrialization. Consequently, the excessive deposition of reactive nitrogen in the environment has generated the loss of biodiversity and eutrophication of different ecosystems. In 2005, a Feammox process was discovered that anaerobically metabolizes ammonium. Feammox with the use of hollow fiber membrane bioreactors (HFMB), based on the formation of biofilms of bacterial communities, has emerged as a possible efficient and sustainable method for ammonium removal in environments with high iron concentrations. This work sought to study the possibility of implementing, at laboratory scale, an efficient method by evaluating the use of HFMB. Samples from an internal circulation reactor (IC) incubated in culture media for Feammox bacteria. The cultures were enriched in a batch reactor to evaluate growth conditions. Next, HFMB assembly was performed, and Feammox parameters were monitored. Also, conventional PCR and scanning electron microscopy (SEM) analysis were performed to characterize the bacterial communities associated with biofilm formation. The use of sodium acetate presented the best performance for Feammox activity. The HFMB operation showed an ammonium (NH4+) removal of 50%. SEM analysis of the fibers illustrated the formation of biofilm networks formed by bacteria, which were identified as Albidiferax ferrireducens, Geobacter spp, Ferrovum myxofaciens, Shewanella spp., and Anammox. Functional genes Archaea/Bacteria ammonia monooxygenase, nrxA, hzsB, nirS and nosZ were also identified. The implementation of HFMB Feammox could be used as a sustainable tool for the removal of ammonium from wastewater produced because of anthropogenic activities.
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Affiliation(s)
- Ámbar Cerda
- Departamento de Química Inorgánica, Facultad de Química y de Farmacia, Pontificia Universidad Católica de Chile, Avenida Vicuña Mackenna 4860, Macul, 7820436, Santiago, Chile.
| | - Carolina Rodríguez
- Departamento de Química Inorgánica, Facultad de Química y de Farmacia, Pontificia Universidad Católica de Chile, Avenida Vicuña Mackenna 4860, Macul, 7820436, Santiago, Chile.
| | - Macarena González
- Departamento de Química Inorgánica, Facultad de Química y de Farmacia, Pontificia Universidad Católica de Chile, Avenida Vicuña Mackenna 4860, Macul, 7820436, Santiago, Chile.
| | - Heylin González
- Departamento de Ingeniería Hidráulica y Ambiental, Pontificia Universidad Católica de Chile, Avenida Vicuña Mackenna 4860, Macul, 7820436, Santiago, Chile.
| | - Jennyfer Serrano
- Escuela de Biotecnología, Universidad Mayor, Camino La Pirámide 5750, Huechuraba, Santiago 8580745, Chile.
| | - Eduardo Leiva
- Departamento de Química Inorgánica, Facultad de Química y de Farmacia, Pontificia Universidad Católica de Chile, Avenida Vicuña Mackenna 4860, Macul, 7820436, Santiago, Chile; Departamento de Ingeniería Hidráulica y Ambiental, Pontificia Universidad Católica de Chile, Avenida Vicuña Mackenna 4860, Macul, 7820436, Santiago, Chile.
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Stoodley P, Toelke N, Schwermer C, de Beer D. Bioenergetics of simultaneous oxygen and nitrate respiration and nitric oxide production in a Pseudomonas aeruginosa agar colony biofilm. Biofilm 2024; 7:100181. [PMID: 38425549 PMCID: PMC10902143 DOI: 10.1016/j.bioflm.2024.100181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 01/09/2024] [Accepted: 02/01/2024] [Indexed: 03/02/2024] Open
Abstract
Pseudomonas aeruginosa is a biofilm forming pathogen commonly associated with infection of the cystic fibrosis (CF) lung, chronic wounds and indwelling medical devices. P. aeruginosa is a facultative aerobe that can use nitrate (NO3-) found in healthy and infected tissues and body fluids to generate energy through denitrification. Further, P. aeruginosa the expression of denitrification genes has been found in specimens from people with CF. The main aim of this study was to determine the relative energy contribution of oxygen (O2) respiration and denitrification in single Pseudomonas aeruginosa PAO1 biofilm colonies under different O2 concentrations to estimate the possible relative importance of these metabolic processes in the context of biofilm infections. We showed that the used strain PAO1 in biofilms denitrified with nitrous oxide (N2O), and not nitrogen (N2), as the end product in our incubations. From simultaneous O2 and N2O microprofiles measured with high spatial resolution by microsensors in agar colony biofilms under air, N2 and pure O2, the rates of aerobic respiration and denitrification were calculated and converted to ATP production rates. Denitrification occurred both in the oxic and anoxic zones, and became increasingly dominant with decreasing O2 concentrations. At O2 concentrations characteristic for tissues and wounds (20-60 μM), denitrification was responsible for 50% of the total energy conservation in the biofilm. In addition the formation of nitric oxide (NO), a precursor of N2O and an important regulator of many cellular processes, was strongly influenced by the local O2 concentrations. NO production was inhibited under pure O2, present under anoxia (∼1 μM) and remarkably high (up to 6 μM) under intermediate O2 levels, which can be found in infected tissues. Possible impacts of such NO levels on both the host and the biofilm bacteria are discussed.
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Affiliation(s)
- Paul Stoodley
- National Centre for Advanced Tribology at Southampton, (NCATS), Mechanical Engineering, University of Southampton, Southampton, SO17 1BJ, UK
- Department of Microbial Infection and Immunity, Department of Orthopaedics, The Ohio State University, 716 Biomedical Research Tower (BRT), 460 W 12th Ave, Columbus OH, 43210, United States
| | - Nina Toelke
- Max Planck Institute for Marine Microbiology (MPI), Microsensor Group and Molecular Ecology Group, Celsiusstrasse 1, D-28359, Bremen, Germany
| | - Carsten Schwermer
- Norwegian Institute for Water Research (NIVA), Gaustadalléen 21, NO-0349, Oslo, Norway
| | - Dirk de Beer
- Max Planck Institute for Marine Microbiology (MPI), Microsensor Group and Molecular Ecology Group, Celsiusstrasse 1, D-28359, Bremen, Germany
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9
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Awala SI, Gwak JH, Kim Y, Jung MY, Dunfield PF, Wagner M, Rhee SK. Nitrous oxide respiration in acidophilic methanotrophs. Nat Commun 2024; 15:4226. [PMID: 38762502 PMCID: PMC11102522 DOI: 10.1038/s41467-024-48161-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Accepted: 04/22/2024] [Indexed: 05/20/2024] Open
Abstract
Aerobic methanotrophic bacteria are considered strict aerobes but are often highly abundant in hypoxic and even anoxic environments. Despite possessing denitrification genes, it remains to be verified whether denitrification contributes to their growth. Here, we show that acidophilic methanotrophs can respire nitrous oxide (N2O) and grow anaerobically on diverse non-methane substrates, including methanol, C-C substrates, and hydrogen. We study two strains that possess N2O reductase genes: Methylocella tundrae T4 and Methylacidiphilum caldifontis IT6. We show that N2O respiration supports growth of Methylacidiphilum caldifontis at an extremely acidic pH of 2.0, exceeding the known physiological pH limits for microbial N2O consumption. Methylocella tundrae simultaneously consumes N2O and CH4 in suboxic conditions, indicating robustness of its N2O reductase activity in the presence of O2. Furthermore, in O2-limiting conditions, the amount of CH4 oxidized per O2 reduced increases when N2O is added, indicating that Methylocella tundrae can direct more O2 towards methane monooxygenase. Thus, our results demonstrate that some methanotrophs can respire N2O independently or simultaneously with O2, which may facilitate their growth and survival in dynamic environments. Such metabolic capability enables these bacteria to simultaneously reduce the release of the key greenhouse gases CO2, CH4, and N2O.
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Affiliation(s)
- Samuel Imisi Awala
- Department of Biological Sciences and Biotechnology, Chungbuk National University, 1 Chungdae-ro, Seowon-Gu, Cheongju, 28644, Republic of Korea
- Center for Ecology and Environmental Toxicology, Chungbuk National University, 1 Chungdae-Ro, Seowon-Gu, Cheongju, 28644, South Korea
| | - Joo-Han Gwak
- Department of Biological Sciences and Biotechnology, Chungbuk National University, 1 Chungdae-ro, Seowon-Gu, Cheongju, 28644, Republic of Korea
| | - Yongman Kim
- Department of Biological Sciences and Biotechnology, Chungbuk National University, 1 Chungdae-ro, Seowon-Gu, Cheongju, 28644, Republic of Korea
| | - Man-Young Jung
- Interdisciplinary Graduate Programme in Advance Convergence Technology and Science, Jeju National University, Jeju, Republic of Korea
- Department of Science Education, Jeju National University, Jeju, Republic of Korea
- Jeju Microbiome Center, Jeju National University, Jeju, Republic of Korea
| | - Peter F Dunfield
- Department of Biological Sciences, University of Calgary, 2500 University Dr. NW, Calgary, AB, T2N 1N4, Canada
| | - Michael Wagner
- Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, Centre for Microbiology and Environmental Systems Science, University of Vienna, Althanstrasse 14, A-1090, Vienna, Austria
- Department of Chemistry and Bioscience, Center for Microbial Communities, Aalborg University, Fredrik Bajers Vej 7H, 9220, Aalborg, Denmark
| | - Sung-Keun Rhee
- Department of Biological Sciences and Biotechnology, Chungbuk National University, 1 Chungdae-ro, Seowon-Gu, Cheongju, 28644, Republic of Korea.
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10
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Nguyen Quoc B, Cavanaugh SK, Hunt KA, Bryson SJ, Winkler MKH. Impact of aerobic granular sludge sizes and dissolved oxygen concentration on greenhouse gas N 2O emission. WATER RESEARCH 2024; 255:121479. [PMID: 38520777 DOI: 10.1016/j.watres.2024.121479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 03/13/2024] [Accepted: 03/14/2024] [Indexed: 03/25/2024]
Abstract
Aerobic granular sludge (AGS) at wastewater treatment plants (WWTPs) are known to produce nitrous oxide (N2O), a greenhouse gas which has a ∼300 times higher global warming potential than carbon dioxide. In this research, we studied N2O emissions from different sizes of AGS developed at a dissolved oxygen (DO) level of 2 mgO2/L while exposing them to disturbances at various DO concentrations ranging from 1 to 4 mgO2/L. Five different AGS size classes were studied: 212-600 µm, 600-1000 µm, 1000-1400 µm, 1400-2000 µm, and > 2000 µm. Metagenomic data showed N2O reductase genes (nosZ) were more abundant in the smaller AGS sizes which aligned with the observation of higher N2O reduction rates in small AGS under anaerobic conditions. However, when oxygen was present, the activity measurements of N2O emission showed an opposite trend compared to metagenomic data, smaller AGS (212 to 1000 µm) emitted significantly higher N2O (p < 0.05) than larger AGS (1000 µm to >2000 µm) at DO of 2, 3, and 4 mgO2/L. The N2O emission rate showed positive correlation with both oxygen levels and nitrification rate. This pattern indicates a connection between N2O emission and nitrification. In addition, the data suggested the penetration of oxygen into the anoxic zone of granules might have hindered nitrous oxide reduction, resulting in incomplete denitrification stopping at N2O and consequently contributing to an increase in N2O emissions. This work sets the stage to better understand the impacts of AGS size on N2O emissions in WWTPs under different disturbance of DO conditions, and thus ensure that wastewater treatment will comply with possible future regulations demanding lowering greenhouse gas emissions in an effort to combat climate change.
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Affiliation(s)
- Bao Nguyen Quoc
- Department of Civil and Environmental Engineering, University of Washington, United States.
| | - Shannon K Cavanaugh
- Department of Civil and Environmental Engineering, University of Washington, United States
| | - Kristopher A Hunt
- Department of Civil and Environmental Engineering, University of Washington, United States
| | - Samuel J Bryson
- Department of Civil and Environmental Engineering, University of Washington, United States
| | - Mari K H Winkler
- Department of Civil and Environmental Engineering, University of Washington, United States
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11
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Thøgersen MS, Zervas A, Stougaard P, Ellegaard-Jensen L. Investigating eukaryotic and prokaryotic diversity and functional potential in the cold and alkaline ikaite columns in Greenland. Front Microbiol 2024; 15:1358787. [PMID: 38655082 PMCID: PMC11035741 DOI: 10.3389/fmicb.2024.1358787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 03/08/2024] [Indexed: 04/26/2024] Open
Abstract
The ikaite columns in the Ikka Fjord, SW Greenland, represent a permanently cold and alkaline environment known to contain a rich bacterial diversity. 16S and 18S rRNA gene amplicon and metagenomic sequencing was used to investigate the microbial diversity in the columns and for the first time, the eukaryotic and archaeal diversity in ikaite columns were analyzed. The results showed a rich prokaryotic diversity that varied across columns as well as within each column. Seven different archaeal phyla were documented in multiple locations inside the columns. The columns also contained a rich eukaryotic diversity with 27 phyla representing microalgae, protists, fungi, and small animals. Based on metagenomic sequencing, 25 high-quality MAGs were assembled and analyzed for the presence of genes involved in cycling of nitrogen, sulfur, and phosphorous as well as genes encoding carbohydrate-active enzymes (CAZymes), showing a potentially very bioactive microbial community.
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12
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Ye R, Huo W, Shao Y, Wang H, Lu W, Zhang H. Fungal community diversity and their contribution to nitrogen cycling in in-situ aerated landfills: Insights from field and laboratory studies. WASTE MANAGEMENT (NEW YORK, N.Y.) 2024; 179:1-11. [PMID: 38442433 DOI: 10.1016/j.wasman.2024.02.048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 02/26/2024] [Accepted: 02/27/2024] [Indexed: 03/07/2024]
Abstract
The application of in-situ aeration technology in landfills has been reported to promote fungal growth, but the community diversity and function of fungi in the aerated landfill system remain unknown. This study firstly investigated an in-situ aerated remediation landfill site to characterize the fungal community diversity in refuse. And to further reveal the fungal involvement in the nitrogen cycling system, laboratory-scale simulated aerated landfill reactors were then constructed. The results in the aerated landfill site showed a significant correlation between fungal community structure and ammonia nitrogen content in the refuse. Dominant fungi in the fungal community included commonly found environmental fungi such as Fusarium, Aspergillus, Gibberella, as well as unique fungi in the aerated system like Chaetomium. In the laboratory-scale aerated landfill simulation experiments, the fungal system was constructed using bacterial inhibitor, and nitrogen balance analysis confirmed the significant role of fungal nitrification in the nitrogen cycling process. When ammonia nitrogen was not readily available, fungi converted organic nitrogen to nitrate, serving as the main nitrification mechanism in the system, with a contribution rate ranging from 62.71 % to 100 % of total nitrification. However, when ammonia nitrogen was present in the system, autotrophic nitrification became the main mechanism, and the contribution of fungal nitrification to total nitrification was only 15.96 %. Additionally, fungi were capable of directly utilizing nitrite for nitrate production with a rate of 4.65 mg L-1 d-1. This research article contributes to the understanding of the importance of fungi in the aerated landfill systems, filling a gap in knowledge.
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Affiliation(s)
- Rong Ye
- School of Environment, Tsinghua University, Beijing 100084, China; Nanjing Institute of Environment Sciences, Ministry of Ecology & Environment, Nanjing 210042, China
| | - Weizhong Huo
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Yuchao Shao
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Hongtao Wang
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Wenjing Lu
- School of Environment, Tsinghua University, Beijing 100084, China.
| | - Houhu Zhang
- Nanjing Institute of Environment Sciences, Ministry of Ecology & Environment, Nanjing 210042, China
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13
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Gao H, Chen N, An N, Zhan Y, Wang H, Feng C. Harnessing the potential of ginkgo biloba extract: Boosting denitrification performance through accelerated electron transfer. CHEMOSPHERE 2024; 352:141368. [PMID: 38316282 DOI: 10.1016/j.chemosphere.2024.141368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2023] [Revised: 01/14/2024] [Accepted: 02/02/2024] [Indexed: 02/07/2024]
Abstract
Ginkgo biloba extract (GBE) had several effects on the human body as one of the widely used phytopharmaceuticals, but it had no application in microbial enhancement in the environmental field. The study focused on the impact of GBE on denitrification specifically under neutral conditions. At the identified optimal addition ratio of 2% (v/v), the system exhibited a noteworthy increase in nitrate reduction rate (NRR) by 56.34%, elevating from 0.71 to 1.11 mg-N/(L·h). Moreover, the extraction of microbial extracellular polymeric substance (EPS) at this ratio revealed changes in the composition of EPS, the electron exchange capacity (EEC) was enhanced from 87.16 to 140.4 μmol/(g C), and the transfer impedance was reduced within the EPS. The flavin, fulvic acid (FA), and humic acid (HA) provided a π-electron conjugated structure for the denitrification system, enhancing extracellular electron transfer (EET) by stimulating carbon source metabolism. GBE also improved electron transfer system activity (ETSA) from 0.025 to 0.071 μL O2/(g·min·prot) and the content of NADH enhanced by 22.90% while significantly reducing the activation energy (Ea) by 85.6% in the denitrification process. The synergy of improving both intracellular and extracellular electron transfer, along with the reduction of Ea, notably amplified the initiation and reduction rates of the denitrification process. Additionally, GBE demonstrated suitability for denitrification across various pH levels, enhancing microbial resilience in alkaline conditions and promoting survival and proliferation. Overall, these findings open the door to potential applications of GBE as a natural additive in the environmental field to improve the efficiency of denitrification processes, which are essential for nitrogen removal in various environmental contexts.
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Affiliation(s)
- Hang Gao
- School of Water Resources and Environment, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing, 100083, China
| | - Nan Chen
- School of Water Resources and Environment, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing, 100083, China.
| | - Ning An
- School of Water Resources and Environment, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing, 100083, China
| | - Yongheng Zhan
- School of Water Resources and Environment, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing, 100083, China
| | - Haishuang Wang
- School of Water Resources and Environment, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing, 100083, China
| | - Chuanping Feng
- School of Water Resources and Environment, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing, 100083, China
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14
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Li Q, Lu H, Tian T, Fu Z, Dai Y, Li P, Zhou J. Insights into the Acceleration Mechanism of Intracellular N and Fe Co-doped Carbon Dots on Anaerobic Denitrification Using Proteomics and Metabolomics Techniques. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:2393-2403. [PMID: 38268063 DOI: 10.1021/acs.est.3c08625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2024]
Abstract
Bulk carbon-based materials can enhance anaerobic biodenitrification when they are present in extracellular matrices. However, little information is available on the effect of nitrogen and iron co-doped carbon dots (N, Fe-CDs) with sizes below 10 nm on this process. This work demonstrated that Fe-NX formed in N, Fe-CDs and their low surface potentials facilitated electron transfer. N, Fe-CDs exhibited good biocompatibility and were effectively absorbed by Pseudomonas stutzeri ATCC 17588. Intracellular N, Fe-CDs played a dominant role in enhancing anaerobic denitrification. During this process, the nitrate removal rate was significantly increased by 40.60% at 11 h with little nitrite and N2O accumulation, which was attributed to the enhanced activities of the electron transport system and various denitrifying reductases. Based on proteomics and metabolomic analysis, N, Fe-CDs effectively regulated carbon/nitrogen/sulfur metabolism to induce more electron generation, less nitrite/N2O accumulation, and higher levels of nitrogen removal. This work reveals the mechanism by which N, Fe-CDs enhance anaerobic denitrification and broaden their potential application in nitrogen removal.
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Affiliation(s)
- Qiansheng Li
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Hong Lu
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Tian Tian
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Ze Fu
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Yi Dai
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Peiwen Li
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Jiti Zhou
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
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15
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Jensen PØ, Olsen P, Dungu AM, Egelund GB, Jensen AV, Ravn P, Lindegaard B, Hertz FB, Bjarnsholt T, Faurholt-Jepsen D, Kolpen M. Bacterial aerobic respiration is a major consumer of oxygen in sputum from patients with acute lower respiratory tract infection. APMIS 2024. [PMID: 38284501 DOI: 10.1111/apm.13381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 01/15/2024] [Indexed: 01/30/2024]
Abstract
Bacterial aerobic respiration may determine the outcome of antibiotic treatment in experimental settings, but the clinical relevance of bacterial aerobic respiration for the outcome of antibiotic treatment has not been tested. Therefore, we hypothesized that bacterial aerobic respiration is higher in sputum from patients with acute lower respiratory tract infections (aLRTI), than in sputum from patients with chronic LRTI (cLRTI), where the bacteria persist despite antibiotic treatment. The bacterial aerobic respiration was determined according to the dynamics of the oxygen (O2 ) concentration in sputum from aLRTI patients (n = 52). This result was evaluated by comparison to previously published data from patients with cLRTI. O2 consumption resulting in anoxic zones was more frequent in sputum with detected bacterial pathogens. The bacterial aerobic respiration in aLRTI sputum approximated 55% of the total O2 consumption, which was significantly higher than previously published for cLRTI. The bacterial aerobic respiration in sputum was higher in aLRTI patients than previously seen in cLRTI patients, indicating the presence of bacteria with a sensitive physiology in aLRTI. These variations in bacterial physiology between aLRTI patients and cLRTI patients may contribute the huge difference in treatment success between the two patient groups.
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Affiliation(s)
- Peter Østrup Jensen
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen, Denmark
- Costerton Biofilm Center, Institute of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Institute for Inflammation Research, Center for Rheumatology and Spine Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Pernille Olsen
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen, Denmark
| | - Arnold Matovu Dungu
- Department of Pulmonary and Infectious Diseases, Copenhagen University Hospital - North Zealand, Hillerød, Denmark
| | - Gertrud Baunbaek Egelund
- Department of Pulmonary and Infectious Diseases, Copenhagen University Hospital - North Zealand, Hillerød, Denmark
| | - Andreas Vestergaard Jensen
- Department of Pulmonary and Infectious Diseases, Copenhagen University Hospital - North Zealand, Hillerød, Denmark
| | - Pernille Ravn
- Department of Medicine Section for Infectious Diseases, Herlev- Gentofte University Hospital, Hellerup, Denmark
| | - Birgitte Lindegaard
- Department of Pulmonary and Infectious Diseases, Copenhagen University Hospital - North Zealand, Hillerød, Denmark
| | | | - Thomas Bjarnsholt
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen, Denmark
- Costerton Biofilm Center, Institute of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Mette Kolpen
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen, Denmark
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16
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Roothans N, Gabriëls M, Abeel T, Pabst M, van Loosdrecht MCM, Laureni M. Aerobic denitrification as an N2O source from microbial communities. THE ISME JOURNAL 2024; 18:wrae116. [PMID: 38913498 PMCID: PMC11272060 DOI: 10.1093/ismejo/wrae116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 04/26/2024] [Accepted: 06/21/2024] [Indexed: 06/26/2024]
Abstract
Nitrous oxide (N2O) is a potent greenhouse gas of primarily microbial origin. Oxic and anoxic emissions are commonly ascribed to autotrophic nitrification and heterotrophic denitrification, respectively. Beyond this established dichotomy, we quantitatively show that heterotrophic denitrification can significantly contribute to aerobic nitrogen turnover and N2O emissions in complex microbiomes exposed to frequent oxic/anoxic transitions. Two planktonic, nitrification-inhibited enrichment cultures were established under continuous organic carbon and nitrate feeding, and cyclic oxygen availability. Over a third of the influent organic substrate was respired with nitrate as electron acceptor at high oxygen concentrations (>6.5 mg/L). N2O accounted for up to one-quarter of the nitrate reduced under oxic conditions. The enriched microorganisms maintained a constitutive abundance of denitrifying enzymes due to the oxic/anoxic frequencies exceeding their protein turnover-a common scenario in natural and engineered ecosystems. The aerobic denitrification rates are ascribed primarily to the residual activity of anaerobically synthesised enzymes. From an ecological perspective, the selection of organisms capable of sustaining significant denitrifying activity during aeration shows their competitive advantage over other heterotrophs under varying oxygen availabilities. Ultimately, we propose that the contribution of heterotrophic denitrification to aerobic nitrogen turnover and N2O emissions is currently underestimated in dynamic environments.
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Affiliation(s)
- Nina Roothans
- Department of Biotechnology, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, the Netherlands
| | - Minke Gabriëls
- Department of Biotechnology, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, the Netherlands
| | - Thomas Abeel
- Delft Bioinformatics Lab, Delft University of Technology, van Mourik Broekmanweg 6, Delft 2628 XE, the Netherlands
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, 415 Main Street, Cambridge, MA 02142, United States
| | - Martin Pabst
- Department of Biotechnology, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, the Netherlands
| | - Mark C M van Loosdrecht
- Department of Biotechnology, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, the Netherlands
| | - Michele Laureni
- Department of Biotechnology, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, the Netherlands
- Department of Water Management, Delft University of Technology, Stevinweg 1, 2628 CN Delft, the Netherlands
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17
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Corbera-Rubio F, Stouten GR, Bruins J, Dost SF, Merkel AY, Müller S, van Loosdrecht MCM, van Halem D, Laureni M. " Candidatus Siderophilus nitratireducens": a putative nap-dependent nitrate-reducing iron oxidizer within the new order Siderophiliales. ISME COMMUNICATIONS 2024; 4:ycae008. [PMID: 38577582 PMCID: PMC10993476 DOI: 10.1093/ismeco/ycae008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Revised: 01/03/2024] [Accepted: 01/17/2024] [Indexed: 04/06/2024]
Abstract
Nitrate leaching from agricultural soils is increasingly found in groundwater, a primary source of drinking water worldwide. This nitrate influx can potentially stimulate the biological oxidation of iron in anoxic groundwater reservoirs. Nitrate-dependent iron-oxidizing (NDFO) bacteria have been extensively studied in laboratory settings, yet their ecophysiology in natural environments remains largely unknown. To this end, we established a pilot-scale filter on nitrate-rich groundwater to elucidate the structure and metabolism of nitrate-reducing iron-oxidizing microbiomes under oligotrophic conditions mimicking natural groundwaters. The enriched community stoichiometrically removed iron and nitrate consistently with the NDFO metabolism. Genome-resolved metagenomics revealed the underlying metabolic network between the dominant iron-dependent denitrifying autotrophs and the less abundant organoheterotrophs. The most abundant genome belonged to a new Candidate order, named Siderophiliales. This new species, "Candidatus Siderophilus nitratireducens," carries genes central genes to iron oxidation (cytochrome c cyc2), carbon fixation (rbc), and for the sole periplasmic nitrate reductase (nap). Using thermodynamics, we demonstrate that iron oxidation coupled to nap based dissimilatory reduction of nitrate to nitrite is energetically favorable under realistic Fe3+/Fe2+ and NO3-/NO2- concentration ratios. Ultimately, by bridging the gap between laboratory investigations and nitrate real-world conditions, this study provides insights into the intricate interplay between nitrate and iron in groundwater ecosystems, and expands our understanding of NDFOs taxonomic diversity and ecological role.
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Affiliation(s)
| | - Gerben R Stouten
- Delft University of Technology, Stevinweg 1, 2628 CN Delft, the Netherlands
| | | | - Simon F Dost
- WMD Water Company Drenthe, Lauwers 3, 9405 BL Assen, the Netherlands
| | - Alexander Y Merkel
- Winogradsky Institute of Microbiology, Research Center of Biotechnology, Russian Academy of Sciences, 60 let Oktjabrja pr-t, 7, bld. 2, 117312 Moscow, Russia
| | - Simon Müller
- Delft University of Technology, Stevinweg 1, 2628 CN Delft, the Netherlands
| | | | - Doris van Halem
- Delft University of Technology, Stevinweg 1, 2628 CN Delft, the Netherlands
| | - Michele Laureni
- Delft University of Technology, Stevinweg 1, 2628 CN Delft, the Netherlands
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18
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Chen J, Shen L, Li Y, Cao H, Chen C, Zhang G, Xu Z, Lu Y. Insights into the nitrogen transformation mechanism of Pseudomonas sp. Y15 capable of heterotrophic nitrification and aerobic denitrification. ENVIRONMENTAL RESEARCH 2024; 240:117595. [PMID: 37926232 DOI: 10.1016/j.envres.2023.117595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Revised: 10/27/2023] [Accepted: 11/02/2023] [Indexed: 11/07/2023]
Abstract
Excessive nitrogen (N) discharged in water is a major cause of eutrophication and other severe environmental issues. Biological N removal via heterotrophic nitrification and aerobic denitrification (HN-AD) has drawn particular attention, owing to the merit of concurrent nitrification and denitrification inside one cell. However, the mechanisms underlying N transformation during HN-AD remain unclear. In the present study, the HN-AD strain Pseudomonas sp. Y15 (Y15) was isolated to explore the N distribution and flow, based on stoichiometry and energetics. The total N removal efficiency by Y15 increased linearly with C/N ratio (in the range of 5-15) to ∼96.8%. Of this, ∼32.2% and ∼64.6% were transformed into gas-N and biomass-N, respectively. A new intracellular N metabolic bypass (NO → NO2) was found, to address the substantial gaseous N production during HN-AD. Concering energetics, the large portion of the biomass-N is ascribed to the synthesis of the amino acids that consume low energy. Finally, two novel stoichiometric equations for different N sources were proposed, to describe the overall HN-AD process. This study deepens the fundamental knowledge on HN-AD bacteria and enlightens their use in treating N-contaminated wastewater.
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Affiliation(s)
- Jinliang Chen
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, The Key Laboratory for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen, 361005, PR China
| | - Liang Shen
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, The Key Laboratory for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen, 361005, PR China.
| | - Yu Li
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, The Key Laboratory for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen, 361005, PR China
| | - Haipeng Cao
- School of Life Sciences, Guizhou Normal University, Guiyang, 550025, PR China
| | - Cuixue Chen
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, The Key Laboratory for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen, 361005, PR China
| | - Guoliang Zhang
- Institute of Oceanic and Environmental Chemical Engineering, State Key Lab Breeding Base of Green Chemical Synthesis Technology, Zhejiang University of Technology, Hangzhou, 310014, PR China
| | - Zehai Xu
- Institute of Oceanic and Environmental Chemical Engineering, State Key Lab Breeding Base of Green Chemical Synthesis Technology, Zhejiang University of Technology, Hangzhou, 310014, PR China
| | - Yinghua Lu
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, The Key Laboratory for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen, 361005, PR China.
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19
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Cao G, Gao J, Song J, Jia X, Liu Y, Niu J, Yuan X, Zhao Y. Performance and mechanism of chromium reduction in denitrification biofilm system with different carbon sources. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 906:167191. [PMID: 37741376 DOI: 10.1016/j.scitotenv.2023.167191] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 09/07/2023] [Accepted: 09/16/2023] [Indexed: 09/25/2023]
Abstract
In the process of biological reduction of Cr(VI), the type of carbon sources affects the rate and effect of Cr(VI) reduction, but its specific performance and influencing mechanism have not yet been explored. In this study, four denitrification biofilm reactors were operated under four common carbon sources (C6H12O6, CH3COONa, CH3OH, CH3COONa:C6H12O6 1:1) to reveal the impact of carbon sources on Cr(VI) reduction. Through preliminary experimental concentration research, 75 mg/L Cr(VI) was selected as the dosing concentration. In long-term operation, the composite carbon sources of CH3COONa and C6H12O6 demonstrated excellent stability and achieved an impressive Cr(VI) removal efficiency of 99.5 %. The following sequence was C6H12O6, CH3COONa, and CH3OH. Among them, CH3OH was less competitive and the system was severely unbalanced with lowest Cr(VI) reduction efficiency. The toxicity reactions, changes in EPS and its functional groups, and electron transfer revealed the reduction and fixation mechanism of chromium on denitrification biofilm. The changes in microbial communities indicated that microbial communities in composite carbon sources can quickly adapt to the high toxic environment. The proportion of Trichococcus reached 43.6 %, which played an important role in denitrification and Cr(VI) reduction. Meanwhile, the prediction of microbial COG function reflected its excellent metabolic ability and defense mechanism.
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Affiliation(s)
- Ge Cao
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China
| | - Junzhi Gao
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China
| | - Jinxin Song
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China
| | - Xvlong Jia
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China
| | - Yinuo Liu
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China
| | - Jiaojiao Niu
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China
| | - Xin Yuan
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China
| | - Yingxin Zhao
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China.
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20
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Hoover RL, Keffer JL, Polson SW, Chan CS. Gallionellaceae pangenomic analysis reveals insight into phylogeny, metabolic flexibility, and iron oxidation mechanisms. mSystems 2023; 8:e0003823. [PMID: 37882557 PMCID: PMC10734462 DOI: 10.1128/msystems.00038-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 09/20/2023] [Indexed: 10/27/2023] Open
Abstract
IMPORTANCE Neutrophilic iron-oxidizing bacteria (FeOB) produce copious iron (oxyhydr)oxides that can profoundly influence biogeochemical cycles, notably the fate of carbon and many metals. To fully understand environmental microbial iron oxidation, we need a thorough accounting of iron oxidation mechanisms. In this study, we show the Gallionellaceae FeOB genomes encode both characterized iron oxidases as well as uncharacterized multiheme cytochromes (MHCs). MHCs are predicted to transfer electrons from extracellular substrates and likely confer metabolic capabilities that help Gallionellaceae occupy a range of different iron- and mineral-rich niches. Gallionellaceae appear to specialize in iron oxidation, so it would be advantageous for them to have multiple mechanisms to oxidize various forms of iron, given the many iron minerals on Earth, as well as the physiological and kinetic challenges faced by FeOB. The multiple iron/mineral oxidation mechanisms may help drive the widespread ecological success of Gallionellaceae.
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Affiliation(s)
- Rene L. Hoover
- Microbiology Graduate Program, University of Delaware, Newark, Delaware, USA
- Department of Earth Sciences, University of Delaware, Newark, Delaware, USA
| | - Jessica L. Keffer
- Department of Earth Sciences, University of Delaware, Newark, Delaware, USA
| | - Shawn W. Polson
- Department of Computer and Information Sciences, University of Delaware, Newark, Delaware, USA
- Center for Bioinformatics and Computational Biology, University of Delaware, Newark, Delaware, USA
| | - Clara S. Chan
- Microbiology Graduate Program, University of Delaware, Newark, Delaware, USA
- Department of Earth Sciences, University of Delaware, Newark, Delaware, USA
- School of Marine Science and Policy, University of Delaware, Newark, Delaware, USA
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21
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Dong J, Yang B, Wang H, Cao X, He F, Wang L. Reveal molecular mechanism on the effects of silver nanoparticles on nitrogen transformation and related functional microorganisms in an agricultural soil. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 904:166765. [PMID: 37660816 DOI: 10.1016/j.scitotenv.2023.166765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 08/29/2023] [Accepted: 08/31/2023] [Indexed: 09/05/2023]
Abstract
Silver nanoparticles (AgNPs) are widely present in aquatic and soil environment, raising significant concerns about their impacts on creatures in ecosystem. While the toxicity of AgNPs on microorganisms has been reported, their effects on biogeochemical processes and specific functional microorganisms remain relatively unexplored. In this study, a 28-day microcosmic experiment was conducted to investigate the dose-dependent effects of AgNPs (10 mg and 100 mg Ag kg-1 soil) on nitrogen transformation and functional microorganisms in agricultural soils. The molecular mechanisms were uncovered by examining change in functional microorganisms and metabolic pathways. To enable comparison, the toxicity of positive control with an equivalent Ag+ dose from CH3COOAg was also included. The results indicated that both AgNPs and CH3COOAg enhanced nitrogen fixation and nitrification, corresponding to increased relative abundances of associated functional genes. However, they inhibited denitrification via downregulating nirS, nirK, and nosZ genes as well as reducing nitrate and nitrite reductase activities. In contrast to high dose of AgNPs, low levels increased bacterial diversity. AgNPs and CH3COOAg altered the activities of associated metabolic pathways, resulting in the enrichment of specific taxa that demonstrated tolerance to Ag. At genus level, AgNPs increased the relative abundances of nitrogen-fixing Microvirga and Bacillus by 0.02 %-629.39 % and 14.44 %-30.10 %, respectively, compared with control group (CK). The abundances of denitrifying bacteria, such as Rhodoplanes, Pseudomonas, and Micromonospora, decreased by 19.03 % to 32.55 %, 24.73 % to 50.05 %, and 15.66 % to 76.06 %, respectively, compared to CK. CH3COOAg reduced bacterial network complexity, diminished the symbiosis mode compared to AgNPs. The prediction of genes involved in metabolic pathways related to membrane transporter and cell motility showed sensitive to AgNPs exposure in the soil. Further studies involving metabolomics are necessary to reveal the essential effects of AgNPs and CH3COOAg on biogeochemical cycle of elements in agricultural soil.
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Affiliation(s)
- Jinhao Dong
- School of Water Conservancy and Environment, University of Jinan, Jinan 250022, China
| | - Baoshan Yang
- School of Water Conservancy and Environment, University of Jinan, Jinan 250022, China; Shandong Provincial Engineering Technology Research Center for Ecological Carbon Sink and Capture Utilization, Jinan 250022, China.
| | - Hui Wang
- School of Water Conservancy and Environment, University of Jinan, Jinan 250022, China; Shandong Provincial Engineering Technology Research Center for Ecological Carbon Sink and Capture Utilization, Jinan 250022, China.
| | - Xinlei Cao
- School of Water Conservancy and Environment, University of Jinan, Jinan 250022, China
| | - Fei He
- Jinan Environmental Research Academy, Jinan 250098, China
| | - Lijiao Wang
- School of Water Conservancy and Environment, University of Jinan, Jinan 250022, China
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22
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Li Y, Su Z, Dai T, Zheng Y, Chen W, Zhao Y, Wen D. Moderate anthropogenic disturbance stimulates versatile microbial taxa contributing to denitrification and aromatic compound degradation. ENVIRONMENTAL RESEARCH 2023; 238:117106. [PMID: 37699472 DOI: 10.1016/j.envres.2023.117106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 08/29/2023] [Accepted: 09/06/2023] [Indexed: 09/14/2023]
Abstract
Wastewater treatment plants (WWTPs) effluent often contains a significant amount of residual organic pollutants and nutrients, causing disturbance to the coastal effluent receiving areas (ERA). Microbial communities in coastal ERA sediments may benefit from the coexistence of organic pollutants and nutrients, promoting the emergence of versatile taxa that are capable of eliminating these substances simultaneously. However, the identification and exploration of versatile taxa in natural environments under anthropogenic disturbances remain largely uncharted territory. In this study, we specifically focused on the versatile taxa coupled by the degradation of aromatic compounds (ACs) and denitrification, using Hangzhou Bay in China as our study area. We explored how WWTPs effluent disturbance would affect the versatile taxa, and particularly examined the role of disturbance intensity in shaping their composition. Intriguingly, we found that versatile taxa were mainly derived from denitrifiers like Pseudomonas, suggesting the fulfilled potential of denitrifiers regarding ACs degradation. We also discovered that moderate disturbance stimulated the diversity of versatile taxa, resulting in strengthened functional redundancy. Through correlation network analysis, we further demonstrated that moderate disturbance enhanced the community-level cooperation. Thus, moderate disturbance serves as a catalyst for versatile taxa to maintain community function, making them more resilient to effluent disturbances. Additionally, we identified COD and NO3--N concentrations as significant environmental factors influencing the versatile taxa. Overall, our findings reveal the role of effluent disturbances in the promotion of versatile taxa, and highlight moderate disturbance can foster more robust versatile taxa that are better equipped to handle effluent disturbances.
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Affiliation(s)
- Yunong Li
- College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China
| | - Zhiguo Su
- School of Environment, Tsinghua University, Beijing, 100084, China
| | - Tianjiao Dai
- School of Water Resources and Environment, China University of Geosciences (Beijing), Beijing, 100083, China
| | - Yuhan Zheng
- College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China
| | - Weidong Chen
- College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China
| | - Yanan Zhao
- College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China
| | - Donghui Wen
- College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China.
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23
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Zhang Y, Bao J, Du J, Mao Q, Cheng B. Comprehensive metagenomic and enzyme activity analysis reveals the inhibitory effects and potential toxic mechanism of tetracycline on denitrification in groundwater. WATER RESEARCH 2023; 247:120803. [PMID: 37922638 DOI: 10.1016/j.watres.2023.120803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2023] [Revised: 09/28/2023] [Accepted: 10/27/2023] [Indexed: 11/07/2023]
Abstract
The widespread use of tetracycline (TC) inevitably leads to its increasing emission into groundwater. However, the potential risks of TC to denitrification in groundwater remain unclear. In this study, the effects of TC on denitrification in groundwater were systematically investigated at both the protein and gene levels from the electron behavior aspect for the first time. The results showed that increasing TC from 0 to 10 µg·L-1 decreased the nitrate removal rate from 0.41 to 0.26 mg·L-1·h-1 while enhancing the residual nitrite concentration from 0.52 mg·L-1 to 50.60 mg·L-1 at the end of the experiment. From a macroscopic view, 10 µg·L-1 TC significantly inhibited microbial growth and altered microbial community structure and function in groundwater, which induced the degeneration of denitrification. From the electron behavior aspect (the electron production, electron transport and electron consumption processes), 10 µg·L-1 TC decreased the concentration of electron donors (nicotinamide adenine dinucleotide, NADH), electron transport system activity, and denitrifying enzyme activities at the protein level. At the gene level, 10 µg·L-1 TC restricted the replication of genes related to carbon metabolism, the electron transport system and denitrification. Moreover, discrepant inhibitory effects of TC on individual denitrification steps, which led to the accumulation of nitrite, were observed in this study. These results provide the information that is necessary for evaluating the potential environmental risk of antibiotics on groundwater denitrification and bring more attention to their effects on geochemical nitrogen cycles.
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Affiliation(s)
- Yi Zhang
- School of Environment Studies, China University of Geosciences, Wuhan 430074, PR China
| | - Jianguo Bao
- School of Environment Studies, China University of Geosciences, Wuhan 430074, PR China.
| | - Jiangkun Du
- School of Environment Studies, China University of Geosciences, Wuhan 430074, PR China
| | - Qidi Mao
- School of Environment Studies, China University of Geosciences, Wuhan 430074, PR China
| | - Benai Cheng
- School of Environment Studies, China University of Geosciences, Wuhan 430074, PR China
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24
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Wu K, Lu X, Chen L, Qin J, Li C, Zhao Q, Ye Z. Evaluating the inhibitory effects of Nitrobenzene short-term stress on denitrification performance: Electron behaviors, bacterial and fungal community. CHEMOSPHERE 2023; 343:140014. [PMID: 37678599 DOI: 10.1016/j.chemosphere.2023.140014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 08/27/2023] [Accepted: 08/28/2023] [Indexed: 09/09/2023]
Abstract
Denitrifying system is a feasible way to remove nitro-aromatic compounds (NACs) in wastewater. However, the toxicity and mechanisms of NACs to denitrification remain unknown. This study investigated effects of nitrobenzene (NB, a typical NAC) on denitrification in short term. Results showed that NB in 10-50 mg/L groups decreased NO3--N removal efficiency by 9%-24%, but increased nitrous oxide (N2O) generation by 6-17fold. Mechanistic research indicated that NB could deteriorate electron behaviors and disturbed enzyme activities of microbial metabolism and denitrification, leading to a decline in denitrification performance. Structural equation modeling revealed that N2O reductase activity was the core factor in predicting denitrification performance at exposure of NB, with the indirect effects of NADH and electron transport system activity. High-throughput sequencing analysis demonstrated that NB had made an alteration on both bacterial and fungal community structure, as well as their interactions.
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Affiliation(s)
- Kun Wu
- Department of Environmental Engineering, Peking University, Beijing, 100871, China.
| | - Xinyue Lu
- Department of Environmental Engineering, Peking University, Beijing, 100871, China
| | - Liuzhou Chen
- Department of Environmental Engineering, Peking University, Beijing, 100871, China
| | - Jiangzhou Qin
- Department of Environmental Engineering, Peking University, Beijing, 100871, China
| | - Chenxi Li
- Department of Environmental Engineering, Peking University, Beijing, 100871, China
| | - Quanlin Zhao
- Department of Environmental Engineering, Peking University, Beijing, 100871, China
| | - Zhengfang Ye
- Department of Environmental Engineering, Peking University, Beijing, 100871, China.
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25
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Li Z, Wang J, Yue H, Du M, Jin Y, Fan J. Marine toxin domoic acid alters nitrogen cycling in sediments. Nat Commun 2023; 14:7873. [PMID: 38036528 PMCID: PMC10689436 DOI: 10.1038/s41467-023-43265-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 11/03/2023] [Indexed: 12/02/2023] Open
Abstract
As a red tide algal toxin with intense neurotoxicity distributed worldwide, domoic acid (DA) has attracted increasing concerns. In this work, the integrative analysis of metagenome and metabolome are applied to investigate the impact of DA on nitrogen cycling in coastal sediments. Here we show that DA can act as a stressor to induce the variation of nitrogen (N) cycling by altering the abundance of functional genes and electron supply. Moreover, microecology theory revealed that DA can increase the role of deterministic assembly in microbial dynamic succession, resulting in the shift of niches and, ultimately, the alteration in N cycling. Notably, denitrification and Anammox, the important process for sediment N removal, are markedly limited by DA. Also, variation of N cycling implies the modification in cycles of other associated elements. Overall, DA is capable of ecosystem-level effects, which require further evaluation of its potential cascading effects.
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Affiliation(s)
- Zelong Li
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, PR China
| | - Jing Wang
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, PR China.
| | - Hao Yue
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, PR China
| | - Miaomiao Du
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, PR China
| | - Yuan Jin
- Marine Ecology Department, National Marine Environmental Monitoring Center, Dalian, 116023, PR China
| | - Jingfeng Fan
- Marine Ecology Department, National Marine Environmental Monitoring Center, Dalian, 116023, PR China.
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26
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Zheng X, Yan Z, Zhao C, He L, Lin Z, Liu M. Homogeneous environmental selection mainly determines the denitrifying bacterial community in intensive aquaculture water. Front Microbiol 2023; 14:1280450. [PMID: 38029183 PMCID: PMC10653326 DOI: 10.3389/fmicb.2023.1280450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 10/18/2023] [Indexed: 12/01/2023] Open
Abstract
Nitrate reduction by napA (encodes periplasmic nitrate reductase) bacteria and nitrous oxide reduction by nosZ (encodes nitrous oxide reductase) bacteria play important roles in nitrogen cycling and removal in intensive aquaculture systems. This study investigated the diversity, dynamics, drivers, and assembly mechanisms of total bacteria as well as napA and nosZ denitrifiers in intensive shrimp aquaculture ponds over a 100-day period. Alpha diversity of the total bacterial community increased significantly over time. In contrast, the alpha diversity of napA and nosZ bacteria remained relatively stable throughout the aquaculture process. The community structure changed markedly across all groups over the culture period. Total nitrogen, phosphate, total phosphorus, and silicate were identified as significant drivers of the denitrifying bacterial communities. Network analysis revealed complex co-occurrence patterns between total, napA, and nosZ bacteria which fluctuated over time. A null model approach showed that, unlike the total community dominated by stochastic factors, napA and nosZ bacteria were primarily governed by deterministic processes. The level of determinism increased with nutrient loading, suggesting the denitrifying community can be manipulated by bioaugmentation. The dominant genus Ruegeria may be a promising candidate for introducing targeted denitrifiers into aquaculture systems to improve nitrogen removal. Overall, this study provides important ecological insights into aerobic and nitrous oxide-reducing denitrifiers in intensive aquaculture, supporting strategies to optimize microbial community structure and function.
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Affiliation(s)
- Xiafei Zheng
- Ninghai Institute of Mariculture Breeding and Seed Industry, Zhejiang Wanli University, Ningbo, China
- Zhejiang Key Laboratory of Aquatic Germplasm Resource, College of Biological and Environmental Sciences, Zhejiang Wanli University, Ningbo, China
| | - Zhongneng Yan
- Ninghai Institute of Mariculture Breeding and Seed Industry, Zhejiang Wanli University, Ningbo, China
- Zhejiang Key Laboratory of Aquatic Germplasm Resource, College of Biological and Environmental Sciences, Zhejiang Wanli University, Ningbo, China
| | - Chenxi Zhao
- Ninghai Institute of Mariculture Breeding and Seed Industry, Zhejiang Wanli University, Ningbo, China
- Zhejiang Key Laboratory of Aquatic Germplasm Resource, College of Biological and Environmental Sciences, Zhejiang Wanli University, Ningbo, China
| | - Lin He
- Ninghai Institute of Mariculture Breeding and Seed Industry, Zhejiang Wanli University, Ningbo, China
- Zhejiang Key Laboratory of Aquatic Germplasm Resource, College of Biological and Environmental Sciences, Zhejiang Wanli University, Ningbo, China
| | - Zhihua Lin
- Ninghai Institute of Mariculture Breeding and Seed Industry, Zhejiang Wanli University, Ningbo, China
- Zhejiang Key Laboratory of Aquatic Germplasm Resource, College of Biological and Environmental Sciences, Zhejiang Wanli University, Ningbo, China
| | - Minhai Liu
- Ninghai Institute of Mariculture Breeding and Seed Industry, Zhejiang Wanli University, Ningbo, China
- Zhejiang Key Laboratory of Aquatic Germplasm Resource, College of Biological and Environmental Sciences, Zhejiang Wanli University, Ningbo, China
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27
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Pavia MJ, Finn D, Macedo-Tafur F, Tello-Espinoza R, Penaccio C, Bouskill N, Cadillo-Quiroz H. Genes and genome-resolved metagenomics reveal the microbial functional make up of Amazon peatlands under geochemical gradients. Environ Microbiol 2023; 25:2388-2403. [PMID: 37501535 DOI: 10.1111/1462-2920.16469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 07/12/2023] [Indexed: 07/29/2023]
Abstract
The Pastaza-Marañón Foreland Basin (PMFB) holds the most extensive tropical peatland area in South America. PMFB peatlands store ~7.07 Gt of organic carbon interacting with multiple microbial heterotrophic, methanogenic, and other aerobic/anaerobic respirations. Little is understood about the contribution of distinct microbial community members inhabiting tropical peatlands. Here, we studied the metagenomes of three geochemically distinct peatlands spanning minerotrophic, mixed, and ombrotrophic conditions. Using gene- and genome-centric approaches, we evaluate the functional potential of the underlying microbial communities. Abundance analyses show significant differences in C, N, P, and S acquisition genes. Furthermore, community interactions mediated by toxin-antitoxin and CRISPR-Cas systems were enriched in oligotrophic soils, suggesting that non-metabolic interactions may exert additional controls in low-nutrient environments. Additionally, we reconstructed 519 metagenome-assembled genomes spanning 28 phyla. Our analyses detail key differences across the geochemical gradient in the predicted microbial populations involved in degradation of organic matter, and the cycling of N and S. Notably, we observed differences in the nitric oxide (NO) reduction strategies between sites with high and low N2 O fluxes and found phyla putatively capable of both NO and sulfate reduction. Our findings detail how gene abundances and microbial populations are influenced by geochemical differences in tropical peatlands.
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Affiliation(s)
- Michael J Pavia
- School of Life Sciences, Arizona State University, Tempe, Arizona, USA
- Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, Tempe, Arizona, USA
| | - Damien Finn
- School of Life Sciences, Arizona State University, Tempe, Arizona, USA
| | - Franco Macedo-Tafur
- Laboratory of Soil Research, Research Institute of Amazonia's Natural Resources, National University of the Peruvian Amazon, Iquitos, Loreto, Peru
| | - Rodil Tello-Espinoza
- Laboratory of Soil Research, Research Institute of Amazonia's Natural Resources, National University of the Peruvian Amazon, Iquitos, Loreto, Peru
- School of Forestry, National University of the Peruvian Amazon, Iquitos, Loreto, Peru
| | - Christa Penaccio
- Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Nicholas Bouskill
- Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Hinsby Cadillo-Quiroz
- School of Life Sciences, Arizona State University, Tempe, Arizona, USA
- Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, Tempe, Arizona, USA
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28
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Venetz J, Żygadłowska OM, Lenstra WK, van Helmond NAGM, Nuijten GHL, Wallenius AJ, Dalcin Martins P, Slomp CP, Jetten MSM, Veraart AJ. Versatile methanotrophs form an active methane biofilter in the oxycline of a seasonally stratified coastal basin. Environ Microbiol 2023; 25:2277-2288. [PMID: 37381163 DOI: 10.1111/1462-2920.16448] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 05/31/2023] [Indexed: 06/30/2023]
Abstract
The potential and drivers of microbial methane removal in the water column of seasonally stratified coastal ecosystems and the importance of the methanotrophic community composition for ecosystem functioning are not well explored. Here, we combined depth profiles of oxygen and methane with 16S rRNA gene amplicon sequencing, metagenomics and methane oxidation rates at discrete depths in a stratified coastal marine system (Lake Grevelingen, The Netherlands). Three amplicon sequence variants (ASVs) belonging to different genera of aerobic Methylomonadaceae and the corresponding three methanotrophic metagenome-assembled genomes (MOB-MAGs) were retrieved by 16S rRNA sequencing and metagenomic analysis, respectively. The abundances of the different methanotrophic ASVs and MOB-MAGs peaked at different depths along the methane oxygen counter-gradient and the MOB-MAGs show a quite diverse genomic potential regarding oxygen metabolism, partial denitrification and sulphur metabolism. Moreover, potential aerobic methane oxidation rates indicated high methanotrophic activity throughout the methane oxygen counter-gradient, even at depths with low in situ methane or oxygen concentration. This suggests that niche-partitioning with high genomic versatility of the present Methylomonadaceae might contribute to the functional resilience of the methanotrophic community and ultimately the efficiency of methane removal in the stratified water column of a marine basin.
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Affiliation(s)
- Jessica Venetz
- Department of Microbiology, Radboud Institute for Biological and Environmental Sciences, Radboud University, Nijmegen, The Netherlands
| | - Olga M Żygadłowska
- Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, The Netherlands
| | - Wytze K Lenstra
- Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, The Netherlands
| | - Niels A G M van Helmond
- Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, The Netherlands
| | - Guylaine H L Nuijten
- Department of Microbiology, Radboud Institute for Biological and Environmental Sciences, Radboud University, Nijmegen, The Netherlands
| | - Anna J Wallenius
- Department of Microbiology, Radboud Institute for Biological and Environmental Sciences, Radboud University, Nijmegen, The Netherlands
| | - Paula Dalcin Martins
- Department of Microbiology, Radboud Institute for Biological and Environmental Sciences, Radboud University, Nijmegen, The Netherlands
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
| | - Caroline P Slomp
- Department of Microbiology, Radboud Institute for Biological and Environmental Sciences, Radboud University, Nijmegen, The Netherlands
- Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, The Netherlands
| | - Mike S M Jetten
- Department of Microbiology, Radboud Institute for Biological and Environmental Sciences, Radboud University, Nijmegen, The Netherlands
| | - Annelies J Veraart
- Department of Aquatic Ecology and Environmental Biology, Radboud Institute for Biological and Environmental Sciences, Radboud University, Nijmegen, The Netherlands
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29
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Wang Q, Lin Y, Peng L, Wang Y, Ma S, Ren H, Xu K. Weak magnetic field enhances waste molasses-driven denitrification during wastewater treatment. BIORESOURCE TECHNOLOGY 2023; 387:129697. [PMID: 37598801 DOI: 10.1016/j.biortech.2023.129697] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 08/13/2023] [Accepted: 08/17/2023] [Indexed: 08/22/2023]
Abstract
Waste molasses, the abundant byproducts of the sugar industry, is a cost-efficient carbon source for advanced denitrification. However, the efficiency of waste molasses-driven denitrification is limited by its complex carbon content, hindering its practical application. Weak magnetic field (WMF) is reported to enhance biological nitrogen removal, but its effects on molasses-driven denitrification remains unknown. This study investigated whether the WMF can enhance waste molasses-driven nitrogen removal and explore the underlying mechanisms. It was found that WMF significantly facilitated waste molasses-driven denitrification, with total nitrogen removal efficiency increased by 1.25 times (from 77% to 96%). WMF stimulated the nitrate reductase's activity by 7-18%, and the enhancement was improved as WMF intensified. Quantitative qPCR analysis indicated that the abundances of denitrifying enzymes increased under WMF, which was consistent with the proliferation of denitrifying bacteria Denitratisoma and Devosia. This study has demonstrated that WMF is promising for enhancing complex carbon-driven denitrification processes.
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Affiliation(s)
- Qingxin Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Yuan Lin
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Ling Peng
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Yanru Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Sijia Ma
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Hongqiang Ren
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Ke Xu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China.
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30
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Zhou Y, Chen Y, Yang J, Xiao L, Jiang L, Wang X, Tang Y. Insight into the enhancing mechanism of exogenous electron mediators on biological denitrification in microbial electrolytic cell. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 896:165096. [PMID: 37355123 DOI: 10.1016/j.scitotenv.2023.165096] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 06/20/2023] [Accepted: 06/21/2023] [Indexed: 06/26/2023]
Abstract
Sustained nitrate accumulation in surface water ecosystem was continuously grabbing public attention. Autotrophic denitrification by electron supplement has been applied to overcome the requirement of carbon source, thus the new problem that how to improve the efficiency of extracellular electrons transfer to denitrifiers comes to us. The addition of exogenous electron mediators has been considered as an important strategy to promote extracellular electrons transfer in reductive metabolism. To date, knowledge is lacking about the promoting effects and pathways in nitrate removal by electron mediators. Here, we fully investigated the performance of nitrogen removal as well as quantified the characteristics of biofilms with six electron mediators (riboflavin, flavin mononucleotide, AQS, AQDS, biochar and Nano-Fe3O4) treating in microbial electrolytic cell system. The six electron mediators promoted nitrate removal rate by 76.03-90.43 % with electron supplement. The growth and activity of cathodic biofilm, conductive nanowires generation and electrochemically active substance synthesis of extracellular polymeric substances were facilitated by electron mediator addition. Electrochemical analysis revealed that conductivity and redox capacity of cathodic biofilm was increased for accelerating electron transfer. Moreover, they upregulated the abundance of denitrifying communities and denitrifying genes accordingly. Their denitrification efficiency varied due to their promotion ability in the above different strategies and conductive characteristics, and the efficiency could be concluded as: Nano-Fe3O4 > riboflavin > flavin mononucleotide > AQS ≈ AQDS > biochar. This study revealed how addition of electron mediators promoted denitrification with electron supplement, and compared their promoting efficiency in several main aspects.
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Affiliation(s)
- Yingping Zhou
- School of the Environment, State Key Laboratory for Pollution Control and Resource Reuse, Nanjing University Xianlin Campus, Nanjing 210023, China
| | - Yuchen Chen
- School of the Environment, State Key Laboratory for Pollution Control and Resource Reuse, Nanjing University Xianlin Campus, Nanjing 210023, China
| | - Jiayi Yang
- School of the Environment, State Key Laboratory for Pollution Control and Resource Reuse, Nanjing University Xianlin Campus, Nanjing 210023, China
| | - Lin Xiao
- School of the Environment, State Key Laboratory for Pollution Control and Resource Reuse, Nanjing University Xianlin Campus, Nanjing 210023, China.
| | - Lijuan Jiang
- School of the Environment, State Key Laboratory for Pollution Control and Resource Reuse, Nanjing University Xianlin Campus, Nanjing 210023, China
| | - Xiaolin Wang
- School of the Environment, State Key Laboratory for Pollution Control and Resource Reuse, Nanjing University Xianlin Campus, Nanjing 210023, China
| | - Yuqiong Tang
- School of the Environment, State Key Laboratory for Pollution Control and Resource Reuse, Nanjing University Xianlin Campus, Nanjing 210023, China
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31
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Chen Y, Yang J, Xiao L, Jiang L, Wang X, Tang Y. Role of Nano-Fe 3O 4 for enhancing nitrate removal in microbial electrolytic cells: Characterizations and microbial patterns of cathodic biofilm. CHEMOSPHERE 2023; 339:139643. [PMID: 37517664 DOI: 10.1016/j.chemosphere.2023.139643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 07/10/2023] [Accepted: 07/23/2023] [Indexed: 08/01/2023]
Abstract
Conductive magnetite nanoparticle (Nano-Fe3O4) can facilitate numerous biological reduction reactions as an outstanding electron mediator for electron transfer. The positive role of Nano-Fe3O4 for nitrate removal has gradually gained attention recent years, however, it has not been clarified for the persistence of the promoting effect under different concentrations addition. Performance of nitrogen removal and characteristics of cathodic biofilm were evaluated in this study after Nano-Fe3O4 addition with gradient concentration of 100∼500 mg L-1 in microbial electrolytic cells (MEC). Our study illustrated that the optimal concentration was 200 mg L-1 as the removal rate of nitrate increased by 24.76% and the removal rate of total dissolved nitrogen by 29.72%. At the optimal concentration, Nano-Fe3O4 increased cathodic biofilm DNA concentration by 61.04%, enhanced electron transport system activity, enriched iron redox bacteria, denitrifying bacteria and genes, as well as increased extracellular polymeric substances (EPS) amount, especially the protein content of soluble-EPS. However, promoting effect on nitrate removal was not visible in high concentration (500 mg L-1) addition, its electron transport system activity and EPS content were even declined. XPS results indicated that high concentration of Nano-Fe3O4 may reduce the availability of electrons to cathodic biofilm by competing for electrons, which inhibit nitrate removal.
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Affiliation(s)
- Yuchen Chen
- School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Jiayi Yang
- School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Lin Xiao
- School of the Environment, Nanjing University, Nanjing, 210023, China; State Key Laboratory for Pollution Control and Resource Reuse, Nanjing University Xianlin Campus, Nanjing, 210023, China.
| | - Lijuan Jiang
- School of the Environment, Nanjing University, Nanjing, 210023, China; State Key Laboratory for Pollution Control and Resource Reuse, Nanjing University Xianlin Campus, Nanjing, 210023, China
| | - Xiaolin Wang
- School of the Environment, Nanjing University, Nanjing, 210023, China; State Key Laboratory for Pollution Control and Resource Reuse, Nanjing University Xianlin Campus, Nanjing, 210023, China
| | - Yuqiong Tang
- School of the Environment, Nanjing University, Nanjing, 210023, China; State Key Laboratory for Pollution Control and Resource Reuse, Nanjing University Xianlin Campus, Nanjing, 210023, China
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Wang C, Qiao S. Electron transfer mechanism of intracellular carbon-dependent DNRA inside anammox bacteria. WATER RESEARCH 2023; 244:120443. [PMID: 37572465 DOI: 10.1016/j.watres.2023.120443] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Revised: 07/31/2023] [Accepted: 08/01/2023] [Indexed: 08/14/2023]
Abstract
Generally, anaerobic ammonium oxidation (anammox) converts nitrite (NO2-) and ammonium (NH4+) to nitrogen gas (N2) but generates some nitrate (NO3-) (equivalent to 11% of inlet total nitrogen (TN)). Although it reported that anammox bacteria could degrade NO3- via dissimilatory nitrate reduction to ammonium (DNRA) pathway using the intracellular carbon as the electron donor, it is still unclear the specific electron transfer mechanism in this intracellular carbon-dependent DNRA inside anammox bacteria, and whether the sole anammox bacteria could achieve higher TN removal efficiency more than the theoretical maximum of 89%. In this study, transcriptome analysis and metabolic inhibitor experiments demonstrated that NADH generated from the decomposition of the intracellular carbon (glycogen) supplied electrons for the NO3-conversion; the electrons were transferred from NADH to nitrate reductase (Nar) and nitrite reductase forming ammonium (NrfA) from ubiquinone (UQ) and complex III, respectively. Combining the intracellular carbon-dependent DNRA with normal anammox process, an average TN removal efficiency of 95% was achieved by the sole anammox bacteria in a sequencing batch reactor. Fluorescent in situ hybridization (FISH) images and real-time fluorescence quantitative PCR (qPCR) results illustrated anammox bacteria could survive and proliferate in the SBR. Our work improved the understanding of the electron transfer mechanism inside anammox bacteria, and further exploit its potential in nitrogen pollutants removal.
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Affiliation(s)
- Chao Wang
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Sen Qiao
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China.
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Heinze BM, Küsel K, Jehmlich N, von Bergen M, Taubert M. Metabolic versatility enables sulfur-oxidizers to dominate primary production in groundwater. WATER RESEARCH 2023; 244:120426. [PMID: 37597444 DOI: 10.1016/j.watres.2023.120426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2023] [Revised: 07/25/2023] [Accepted: 07/27/2023] [Indexed: 08/21/2023]
Abstract
High rates of CO2 fixation and the genetic potential of various groundwater microbes for autotrophic activity have shown that primary production is an important source of organic C in groundwater ecosystems. However, the contribution of specific chemolithoautotrophic groups such as S-oxidizing bacteria (SOB) to groundwater primary production and their adaptation strategies remain largely unknown. Here, we stimulated anoxic groundwater microcosms with reduced S and sampled the microbial community after 1, 3 and 6 weeks. Genome-resolved metaproteomics was combined with 50at-% 13CO2 stable isotope probing to follow the C flux through the microbial food web and infer traits expressed by active SOB in the groundwater microcosms. Already after 7 days, 90% of the total microbial biomass C in the microcosms was replaced by CO2-derived C, increasing to 97% at the end of incubation. Stable Isotope Cluster Analysis revealed active autotrophs, characterized by a uniform 13C-incorporation of 45% in their peptides, to dominate the microbial community throughout incubation. Mixo- and heterotrophs, characterized by 10 to 40% 13C-incorporation, utilized the primarily produced organic C. Interestingly, obligate autotrophs affiliated with Sulfuricella and Sulfuritalea contained traits enabling the storage of elemental S in globules to maintain primary production under energy limitation. Others related to Sulfurimonas seemed to rapidly utilize substrates for fast proliferation, and most autotrophs further maximized their energy yield via efficient denitrification and the potential for H2 oxidation. Mixotrophic SOB, belonging to Curvibacter or Polaromonas, enhanced metabolic flexibility by using organic compounds to satisfy their C requirements. Time series data spanning eight years further revealed that key taxa of our microcosms composed up to 15% of the microbial groundwater community, demonstrating their in-situ importance. This showed that SOB, by using different metabolic strategies, are able to account for high rates of primary production in groundwater, especially at sites limited to geogenic nutrient sources. The widespread presence of SOB with traits such as S storage, H2 oxidation, and organic C utilization in many aquatic habitats further suggested that metabolic versatility governs S-fueled primary production in the environment.
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Affiliation(s)
- Beatrix M Heinze
- Aquatic Geomicrobiology, Institute of Biodiversity, Friedrich Schiller University Jena, Dornburger Str. 159, Jena 07743, Germany
| | - Kirsten Küsel
- Aquatic Geomicrobiology, Institute of Biodiversity, Friedrich Schiller University Jena, Dornburger Str. 159, Jena 07743, Germany; The German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Puschstr. 4, Leipzig 04103, Germany; Cluster of Excellence Balance of the Microverse, Friedrich Schiller University Jena, Jena, Germany
| | - Nico Jehmlich
- Department of Molecular Systems Biology, Helmholtz Centre for Environmental Research, UFZ, Permoserstr. 15, Leipzig 04318, Germany
| | - Martin von Bergen
- The German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Puschstr. 4, Leipzig 04103, Germany; Department of Molecular Systems Biology, Helmholtz Centre for Environmental Research, UFZ, Permoserstr. 15, Leipzig 04318, Germany; Faculty of Biosciences, Pharmacy and Psychology, Institute of Biochemistry, University of Leipzig, Brüderstr. 32, Leipzig 04103, Germany
| | - Martin Taubert
- Aquatic Geomicrobiology, Institute of Biodiversity, Friedrich Schiller University Jena, Dornburger Str. 159, Jena 07743, Germany; Cluster of Excellence Balance of the Microverse, Friedrich Schiller University Jena, Jena, Germany.
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Chen Z, Pang C, Wen Q. Coupled pyrite and sulfur autotrophic denitrification for simultaneous removal of nitrogen and phosphorus from secondary effluent: feasibility, performance and mechanisms. WATER RESEARCH 2023; 243:120422. [PMID: 37523921 DOI: 10.1016/j.watres.2023.120422] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 07/11/2023] [Accepted: 07/26/2023] [Indexed: 08/02/2023]
Abstract
The discharge standards of nitrogen (N) and phosphorus (P) in wastewater treatment plants (WWTPs) have become increasingly strict to reduce water eutrophication. Further reducing N and P in effluent from municipal WWTPs need to be achieved effectively and eco-friendly. In this study, a carbon independent pyrite and sulfur autotrophic denitrification (PSAD) system using pyrite and sulfur as electron donor was developed and compared with pyrite autotrophic denitrification (PAD) and sulfur autotrophic denitrification (SAD) systems through batch and continuous flow biofilter experiments. Compare to PAD and SAD, PSAD was more effective in simultaneous removal in N and P. At hydraulic retention time (HRT) 3 h, average effluent concentrations of total nitrogen (TN) and total phosphate (TP) of 1.40 ± 0.03 and 0.19 ± 0.02 mg/L were achieved when treating real secondary effluent with 20.65 ± 0.24 mg/L TN and 1.00 ± 0.24 mg/L TP. The improvement in simultaneous removal of N and P was attributed to the coupling of PAD and SAD in enhancing the transformation of sulfur and iron and enlarging the reaction zone in the pyrite and sulfur autotrophic denitrification biofilter (PSADB) system. Therefore, more biomass was accumulated and the microbial denitrification functional stability, including electrons transfer and consumption was enhanced on the surface of pyrite and sulfur particles in the PSADB system. Moreover, autotrophic denitrifiers (Thiobacillus and Ferritrophicum), sulfate-reducing bacteria (Desulfocapsa) and iron reducing bacteria (Geothrix), acting as contributors to microbial nitrogen, sulfur and iron cycle, were specially enriched. In addition, the leaching of iron ions was promoted, which facilitated the removal of phosphate in the form of Fe3(PO4)2·8H2O and Fe3PO4. PSADB has proven to be an efficient technology for simultaneous removal of N and P, which could meet increasingly stringent discharge standards effectively and eco-friendly.
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Affiliation(s)
- Zhiqiang Chen
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Chao Pang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Qinxue Wen
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China.
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Li J, Cai L, Lu H, Ma B, Chen G, Kong D, Hu Y, Ye Z, Ruan Y. Effects of Ion Combinations and Their Concentrations on Denitrification Performance and Gene Expressions of an Aerobic Strain Marinobacter Hydrocarbonoclasticus RAD-2. Microorganisms 2023; 11:1867. [PMID: 37630427 PMCID: PMC10456938 DOI: 10.3390/microorganisms11081867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 07/17/2023] [Accepted: 07/18/2023] [Indexed: 08/27/2023] Open
Abstract
Salinity is one of the most important factors affecting the nitrogen-removal efficiency of denitrifying bacteria. A series of different ion combinations and salinity gradients were carried out to clarify the effects of ion types and concentrations on nitrogen removal by halophilic aerobic denitrifying bacteria RAD-2. Nitrate concentrations, nitrite concentrations, TAN concentrations, and OD600 were monitored to investigate their effects on denitrification in each group. The results showed that Na+, K+, and Cl- accelerated the denitrification process and improved nitrogen-removal efficiency at moderate additions, while Ca2+ and Mg2+ showed no significant effect. Na+ was effective alone, while K+ or Cl- needed to be combined with at least one of Na+, K+, or Cl- to achieve similar efficiency. The batch tests of salinity confirmed that the addition of a moderate concentration of NaCl/Na2SO4 could effectively improve nitrogen-removal efficiency, while excessive salinity might hinder denitrification metabolism. In the salinity range of 5~40‱, a 5‱ dosage might be the most economical method for strain RAD-2. Real-time PCR experiments on 17 key nitrogen metabolism-related genes revealed that chloride was widely involved in the nitrogen and carbon metabolism of microorganisms by altering cell osmotic pressure and opening ion channel proteins, thereby affecting the efficiency of denitrification. The results of this study may contribute to a better understanding of the different roles of various ions in aerobic denitrification and highlight the importance of salinity control in highly salted wastewater treatment.
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Affiliation(s)
- Junchi Li
- Institute of Agricultural Bio-Environmental Engineering, College of Bio-Systems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China; (J.L.); (Y.H.)
- The Rural Development Academy, Zhejiang University, Hangzhou 310058, China;
| | - Lei Cai
- Laboratory of Microbial Resources, College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310035, China;
| | - Huifeng Lu
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China;
| | - Bin Ma
- Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China;
| | - Guangsuo Chen
- The Rural Development Academy, Zhejiang University, Hangzhou 310058, China;
| | - Dedong Kong
- Institute of Digital Agriculture, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China; (D.K.); (Z.Y.)
| | - Yiming Hu
- Institute of Agricultural Bio-Environmental Engineering, College of Bio-Systems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China; (J.L.); (Y.H.)
- The Rural Development Academy, Zhejiang University, Hangzhou 310058, China;
| | - Ziran Ye
- Institute of Digital Agriculture, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China; (D.K.); (Z.Y.)
| | - Yunjie Ruan
- Institute of Agricultural Bio-Environmental Engineering, College of Bio-Systems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China; (J.L.); (Y.H.)
- The Rural Development Academy, Zhejiang University, Hangzhou 310058, China;
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36
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Ju CJ, Niyazi S, Cao WY, Wang Q, Chen RP, Yu L. Characteristics and comparisons of the aerobic and anaerobic denitrification of a Klebsiella oxytoca strain: Performance, electron transfer pathway, and mechanism. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 338:117787. [PMID: 36965422 DOI: 10.1016/j.jenvman.2023.117787] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 03/10/2023] [Accepted: 03/20/2023] [Indexed: 06/18/2023]
Abstract
The performance and electron (e-) transfer mechanisms of anaerobic and aerobic denitrification by strain Klebsiella were investigated in this study. The RT-PCR results demonstrated that the membrane bound nitrate reductase gene (narG) and Cu-nitrite reductase gene (nirK) were responsible for both aerobic and anerobic denitrification. The extreme low gene relative abundance of nirK might be responsible for the severe accumulation of NO2--N (nitrogen in the form of NO2- ion) under anaerobic condition. Moreover, the nitrite reductase (Nir) activity was 0.31 μg NO2--N min-1 mg-1 protein under anaerobic conditions, which was lower than that under aerobic conditions (0.38 μg NO2--N min-1 mg-1 protein). By using respiration chain inhibitors, the e- transfer pathways of anaerobic and aerobic denitrification of Klebsiella strain were constructed. Fe-S protein and Complex III were the core components under anaerobic conditions, while Coenzyme Q (CoQ), Complexes I and III played a key role in aerobic denitrification. Nitrogen assimilation was found to be the main way to generate NH4+-N (nitrogen in the form of NH4+ ion) during anaerobic denitrification, and also served as the primary nitrogen removal way under aerobic condition. The results of this study may help to improve the understanding of the core components of strain Klebsiella during aerobic and anaerobic denitrifications, and may suggest potential applications of the strain for nitrogen-containing wastewater.
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Affiliation(s)
- Cheng-Jia Ju
- Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, China; College of Biology and the Environment, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China
| | - Shareen Niyazi
- Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, China
| | - Wen-Yin Cao
- Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, China
| | - Quan Wang
- Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, China
| | - Rong-Ping Chen
- Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, China
| | - Lei Yu
- Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, China; College of Biology and the Environment, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China.
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Wang F, Li L, Li X, Hu X, Zhang B. Pulsed electric field promotes the growth metabolism of aerobic denitrifying bacteria Pseudomonas putida W207-14 by improving cell membrane permeability. ENVIRONMENTAL TECHNOLOGY 2023; 44:2327-2340. [PMID: 35001840 DOI: 10.1080/09593330.2022.2027028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 12/11/2021] [Indexed: 06/04/2023]
Abstract
The purpose of this study was to explore the stimulation mechanism of low pulsed electric field (PEF) strength treatment to promote the growth metabolism of aerobic denitrifying bacteria Pseudomonas putida W207-14. The results indicated that compared with the control group, the strain W207-14 treated with PEF entered the logarithmic growth phase 5 h earlier, the growth time to reached the maximum cell optical density at 600 nm (OD600) of 1.935 ± 0.04 was only 24 h, which shortened by half. With the reduction of growth time, the metabolic rate of the strain increased significantly, in which the removal efficiency of COD, NO3--N and TN was 97.67 ± 1.12%, 90.34 ± 0.73% and 90.13 ± 0.10% in 24 h, respectively. The maximum nitrate removal rate increased from 3.49 mg/L/h to 7.53 mg/L/h. A large number of cells with simultaneous cell membrane damage and high physiological activity were observed by flow cytometry (FCM) in combination with fluorescence staining analysis, which confirmed the reversible electroporation on the cell membrane of strain W207-14 treated with PEF. Transcriptomic analysis indicated that PEF activated the highly significant differential expression of membrane porin (opdB, opdC, and oprB) and cytochrome oxidoreductase related genes (ccoP, ccoN, cioA and cioB) on the cell membrane, which promoted the transport of nutrients through the cell membrane and electron transfer during aerobic respiration and provided an explanation for the possible mechanism of PEF promoting the growth metabolism of strain W207-14 at the micro level. These results lay a foundation for the practical application of PEF enhanced aerobic denitrification technology.
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Affiliation(s)
- Fan Wang
- School of Resource & Civil Engineering, Northeastern University, Shenyang, People's Republic of China
| | - Liang Li
- School of Resource & Civil Engineering, Northeastern University, Shenyang, People's Republic of China
| | - Xuejie Li
- School of Resource & Civil Engineering, Northeastern University, Shenyang, People's Republic of China
| | - Xiaomin Hu
- School of Resource & Civil Engineering, Northeastern University, Shenyang, People's Republic of China
| | - Bo Zhang
- School of Resource & Civil Engineering, Northeastern University, Shenyang, People's Republic of China
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Wu T, Zhong L, Pang JW, Ren NQ, Ding J, Yang SS. Effect of Fe3+ on the nutrient removal performance and microbial community in a biofilm system. Front Microbiol 2023; 14:1140404. [PMID: 37089551 PMCID: PMC10117941 DOI: 10.3389/fmicb.2023.1140404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 03/22/2023] [Indexed: 04/08/2023] Open
Abstract
In this study, the influence of Fe3+ on N removal, microbial assembly, and species interactions in a biofilm system was determined. The results showed that maximum efficiencies of ammonia nitrogen (NH4+-N), total nitrogen (TN), phosphorus (P), and chemical oxygen demand (COD) removal were achieved using 10 mg/L Fe3+, reaching values of 100, 78.85, 100, and 95.8%, respectively, whereas at concentrations of 15 and 30 mg/L Fe3+ suppressed the removal of NH4+-N, TN, and COD. In terms of absolute abundance, the expression of bacterial amoA, narG, nirK, and napA was maximal in the presence of 10 mg/L Fe3+ (9.18 × 105, 8.58 × 108, 1.09 × 108, and 1.07 × 109 copies/g dry weight, respectively). Irrespective of Fe3+ concentrations, the P removal efficiency remained at almost 100%. Candidatus_Competibacter (10.26–23.32%) was identified as the most abundant bacterial genus within the system. Determinism (50%) and stochasticity (50%) contributed equally to microbial community assembly. Co-occurrence network analysis revealed that in the presence of Fe3+, 60.94% of OTUs in the biofilm system exhibited positive interactions, whereas 39.06% exhibited negative interactions. Within the OTU-based co-occurrence network, fourteen species were identified as key microbes. The stability of the system was found to be predominantly shaped by microbial cooperation, complemented by competition for resources or niche incompatibility. The results of this study suggested that during chemical P removal in wastewater treatment plants using biofilm methods, the concentration of supplemental Fe3+ should be maintained at 10 mg/L, which would not only contribute to P elimination, but also enhance N and COD removal.
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Affiliation(s)
- Tong Wu
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, China
| | - Le Zhong
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, China
| | - Ji-Wei Pang
- China Energy Conservation and Environmental Protection Group, CECEP Talroad Technology Co., Ltd., Beijing, China
| | - Nan-Qi Ren
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, China
| | - Jie Ding
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, China
- *Correspondence: Jie Ding,
| | - Shan-Shan Yang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, China
- Shan-Shan Yang,
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Liao Y, Bian J, Miao S, Xu S, Li R, Liu R, Liu H, Qu J. Regulation of denitrification performance and microbial topology by lights: Insight into wavelength effects towards microbiota. WATER RESEARCH 2023; 232:119434. [PMID: 36746030 DOI: 10.1016/j.watres.2022.119434] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 11/20/2022] [Accepted: 11/26/2022] [Indexed: 06/18/2023]
Abstract
The low efficiency of conventional complete denitrification, as well as the unstable nitrite supply for partial-denitrification coupled anammox (PD/A) restrict the efficient removal of nitrogen from industrial wastewaters. Herein, we proposed an optical strategy to bidirectionally regulate denitrification by introducing lights at different wavelengths, and the underlying mechanisms were elucidated accordingly. It turned out that yellow light at wavelength of 590 nm accelerated denitrification by 35.4%, while blue light delayed denitrification with stable nitrite accumulation above 86.9% and high nitrate removal (99.8%). Microbial physiology and viability further supported the positive effects of yellow light on microbial activity. Additionally, despite the sluggish denitrification aroused by blue light, negligible cellular damage was observed. Antioxidant capability divergence, microbial community shifting and metabolic flux redirection contributed to the wavelength-dependent effects. Halomonas and Pseudomonas were identified as high-credit taxonomic biomarkers of yellow and blue light. As revealed by metabolomics, pantothenate and CoA biosynthesis, glutamate metabolism and alkaloid biosynthesis presented high impact values. Co-analysis of metabolomics and metagenomics based on microbial topology further distinguished pivotal metabolic pathways and genes. Oxidative phosphorylation contributed to the divergent denitrification performance through electron transfer chains, whereas glutamate and glutathione metabolism contributed to oxidative stress alleviation and mediated the metabolic flux between peroxisome and nitrogen metabolism. This study shed a light on the application of optical strategy to regulate denitrification performance and achieve either complete denitrification or PD/A.
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Affiliation(s)
- Yang Liao
- Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Jiyong Bian
- Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Shiyu Miao
- Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Siqi Xu
- Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Rui Li
- Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Ruiping Liu
- Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
| | - Huijuan Liu
- Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Jiuhui Qu
- Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
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40
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Goethite and riboflavin synergistically enhance Cr(VI) reduction by Shewanella oneidensis MR-1. Biodegradation 2023; 34:155-167. [PMID: 36592293 DOI: 10.1007/s10532-022-10010-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 12/14/2022] [Indexed: 01/03/2023]
Abstract
Bioreduction of Cr(VI) is cost-effective and environmentally friendly, however, the slow bioreduction rate limits its application. In this study, the potential synergistic enhancement of Cr(VI) bioreduction by shewanella oneidensis MR-1 (S. oneidensis) with goethite and riboflavin (RF) was investigated. The results showed that the S. oneidensis reaction system reduce 29.2% of 20 mg/L Cr(VI) after 42 h reaction, while the S. oneidensis/goethite/RF reaction system increased the Cr(VI) reduction rate to 87.74%. RF as an efficient electron shuttle and Fe(II) from goethite bioreduction were identified as the crucial components in Cr(VI) reduction. XPS analysis showed that the final precipitates of Cr(VI) reduction were Cr(CH3C(O)CHC(O)CH3)3 and Cr2O3 and adhered to the bacterial cell surface. In this process, the microbial surface functional groups such as hydroxyl and carboxyl groups participated in the adsorption and reduction of Cr(VI). Meanwhile, an increase in cytochrome c led to an increase in electron transfer system activity (ETSA), causing a significant enhancement in extracellular electron transfer efficiency. This study provides insight into the mechanism of Cr(VI) reduction in a complex environment where microorganisms, iron minerals and RF coexist, and the synergistic treatment method of Fe(III) minerals and RF has great potential application for Cr(VI) detoxification in aqueous environment.
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Jiang G, Liu Y, Liu X, Shen Y, Zhang A, Li Z. Enhanced efficiency and mechanism of low-temperature biochar on simultaneous removal of nitrogen and phosphorus by combined heterotrophic nitrification-aerobic denitrification bacteria. BIORESOURCE TECHNOLOGY 2023; 373:128720. [PMID: 36774989 DOI: 10.1016/j.biortech.2023.128720] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 02/04/2023] [Accepted: 02/07/2023] [Indexed: 06/18/2023]
Abstract
In this study, three strains of heterotrophic nitrification-aerobic denitrification (HN-AD) capable of simultaneously removing phosphorus were isolated from activated sludge, and low-temperature coconut shell biochar was prepared. The metabolic effects of combined HN-AD bacteria on the total nitrogen (TN) and total phosphorus (TP) were investigated, and the enhanced efficiency and mechanism of low-temperature biochar on the combined bacteria were also explored. The results indicated that the combined bacteria could adapt to environmental impacts and multiple nitrogen sources. The low-temperature biochar containing more aliphatic carbon and oxygen-containing functional groups enhanced the metabolic activity of combined HN-AD bacteria and accelerated the electron transfer process during nitrogen and phosphorus degradation. The removal efficiencies of TN and TP increased by 68% and 88%, respectively, in the treatment of actual sewage by biochar attached with combined bacteria. The findings form a basis for the engineering utilization of HN-AD and are of great practical significance.
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Affiliation(s)
- Ge Jiang
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Yan Ta Road. No.13, Xi'an 710055, China
| | - Yongjun Liu
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Yan Ta Road. No.13, Xi'an 710055, China.
| | - Xingshe Liu
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Yan Ta Road. No.13, Xi'an 710055, China
| | - Yuan Shen
- Yishuiyuan Biotechnology (Xi'an) Co., Ltd., Xi'an 710018, China
| | - Aining Zhang
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Yan Ta Road. No.13, Xi'an 710055, China
| | - Zhihua Li
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Yan Ta Road. No.13, Xi'an 710055, China
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Miralles-Robledillo JM, Martínez-Espinosa RM, Pire C. Analysis of the external signals driving the transcriptional regulation of the main genes involved in denitrification in Haloferax mediterranei. Front Microbiol 2023; 14:1109550. [PMID: 37007523 PMCID: PMC10062603 DOI: 10.3389/fmicb.2023.1109550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Accepted: 02/21/2023] [Indexed: 03/18/2023] Open
Abstract
Haloferax mediterranei is the model microorganism for the study of the nitrogen cycle in haloarchaea. This archaeon not only assimilate N-species such as nitrate, nitrite, or ammonia, but also it can perform denitrification under low oxygen conditions, using nitrate or nitrite as alternative electron acceptors. However, the information currently available on the regulation of this alternative respiration in this kind of microorganism is scarce. Therefore, in this research, the study of haloarchaeal denitrification using H. mediterranei has been addressed by analyzing the promoter regions of the four main genes of denitrification (narGH, nirK, nor, and nosZ) through bioinformatics, reporter gene assays under oxic and anoxic conditions and by site-directed mutagenesis of the promoter regions. The results have shown that these four promoter regions share a common semi-palindromic motif that plays a role in the control of the expression levels of nor and nosZ (and probably nirK) genes. Regarding the regulation of the genes under study, it has been concluded that nirK, nor, and nosZ genes share some expression patterns, and therefore their transcription could be under the control of the same regulator whereas nar operon expression displays differences, such as the activation by dimethyl sulfoxide with respect to the expression in the absence of an electron acceptor, which is almost null under anoxic conditions. Finally, the study with different electron acceptors demonstrated that this haloarchaea does not need complete anoxia to perform denitrification. Oxygen concentrations around 100 μM trigger the activation of the four promoters. However, a low oxygen concentration per se is not a strong signal to activate the promoters of the main genes involved in this pathway; high activation also requires the presence of nitrate or nitrite as final electron acceptors.
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Affiliation(s)
- Jose María Miralles-Robledillo
- Biochemistry and Molecular Biology Division, Agrochemistry and Biochemistry Department, Faculty of Sciences, University of Alicante, Alicante, Spain
| | - Rosa María Martínez-Espinosa
- Biochemistry and Molecular Biology Division, Agrochemistry and Biochemistry Department, Faculty of Sciences, University of Alicante, Alicante, Spain
- Multidisciplinary Institute for Environmental Studies “Ramón Margalef”, University of Alicante, Alicante, Spain
| | - Carmen Pire
- Biochemistry and Molecular Biology Division, Agrochemistry and Biochemistry Department, Faculty of Sciences, University of Alicante, Alicante, Spain
- Multidisciplinary Institute for Environmental Studies “Ramón Margalef”, University of Alicante, Alicante, Spain
- *Correspondence: Carmen Pire,
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43
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Wang Z, Vishwanathan N, Kowaliczko S, Ishii S. Clarifying Microbial Nitrous Oxide Reduction under Aerobic Conditions: Tolerant, Intolerant, and Sensitive. Microbiol Spectr 2023; 11:e0470922. [PMID: 36926990 PMCID: PMC10100939 DOI: 10.1128/spectrum.04709-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 02/18/2023] [Indexed: 03/17/2023] Open
Abstract
One of the major challenges for the bioremediation application of microbial nitrous oxide (N2O) reduction is its oxygen sensitivity. While a few strains were reported capable of reducing N2O under aerobic conditions, the N2O reduction kinetics of phylogenetically diverse N2O reducers are not well understood. Here, we analyzed and compared the kinetics of clade I and clade II N2O-reducing bacteria in the presence or absence of oxygen (O2) by using a whole-cell assay with N2O and O2 microsensors. Among the seven strains tested, N2O reduction of Stutzerimonas stutzeri TR2 and ZoBell was not inhibited by oxygen (i.e., oxygen tolerant). Paracoccus denitrificans, Azospirillum brasilense, and Gemmatimonas aurantiaca reduced N2O in the presence of O2 but slower than in the absence of O2 (i.e., oxygen sensitive). N2O reduction of Pseudomonas aeruginosa and Dechloromonas aromatica did not occur when O2 was present (i.e., oxygen intolerant). Amino acid sequences and predicted structures of NosZ were highly similar among these strains, whereas oxygen-tolerant N2O reducers had higher oxygen consumption rates. The results suggest that the mechanism of O2 tolerance is not directly related to NosZ structure but is rather related to the scavenging of O2 in the cells and/or accessory proteins encoded by the nos cluster. IMPORTANCE Some bacteria can reduce N2O in the presence of O2, whereas others cannot. It is unclear whether this trait of aerobic N2O reduction is related to the phylogeny and structure of N2O reductase. The understanding of aerobic N2O reduction is critical for guiding emission control, due to the common concurrence of N2O and O2 in natural and engineered systems. This study provided the N2O reduction kinetics of various bacteria under aerobic and anaerobic conditions and classified the bacteria into oxygen-tolerant, -sensitive, and -intolerant N2O reducers. Oxygen-tolerant N2O reducers rapidly consumed O2, which could help maintain the low O2 concentration in the cells and keep their N2O reductase active. These findings are important and useful when selecting N2O reducers for bioremediation applications.
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Affiliation(s)
- Zhiyue Wang
- Department of Civil and Environmental Engineering, University of Hawai'i, Honolulu, Hawai'i, USA
- Water Resources Research Center, University of Hawai'i, Honolulu, Hawai'i, USA
| | - Nisha Vishwanathan
- BioTechnology Institute, University of Minnesota, St. Paul, Minnesota, USA
| | - Sophie Kowaliczko
- BioTechnology Institute, University of Minnesota, St. Paul, Minnesota, USA
| | - Satoshi Ishii
- BioTechnology Institute, University of Minnesota, St. Paul, Minnesota, USA
- Department of Soil, Water, and Climate, University of Minnesota, St. Paul, Minnesota, USA
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44
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Yu C, Qiao S, Zhou J. Sulfide-driven nitrous oxide recovery during the mixotrophic denitrification process. J Environ Sci (China) 2023; 125:443-452. [PMID: 36375927 DOI: 10.1016/j.jes.2021.12.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 12/02/2021] [Accepted: 12/03/2021] [Indexed: 06/16/2023]
Abstract
We propose a novel sulfide-driven process to recover N2O during the traditional denitrification process. The optimum initial sulfide concentration was 120 mg/L, and the N2O percentage in the gaseous products (N2O+N2) was up to 82.9%. Moreover, sulfide involved in denitrification processes could substitute for organic carbon as an electron donor, e.g., 1 g sulfide was equivalent to 0.5-2 g COD when sulfide was oxidized to sulfur and sulfate. The accumulation of N2O was mainly due to the inhibiting effect of sulfide on nitrous oxide reductase (N2OR), which was induced by the supply insufficiency of electrons from cytochrome c (cyt c) to N2OR. When the initial sulfide concentration was 120 mg/L, the N2OR activity was only 36.8% of its original level. According to the results of cyclic voltammetry, circular dichroism spectra and fluorescence spectra, significant changes in the conformations and protein structures of cyt c were caused by sulfide, and cyt c completely lost its electron transport capacity. This study provides a new concept for N2O recovery driven by sulfide in the denitrification process. In addition, the findings regarding the mechanism of the inhibition of N2OR activity have important implications both for reducing emissions of N2O and recovering N2O in the sulfide-driven denitrification process.
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Affiliation(s)
- Cong Yu
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Sen Qiao
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China.
| | - Jiti Zhou
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
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45
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Zhao Y, Jia X, Wang Q, Wu Y, Jia Z, Zhou X, Ji M. PMo 12 as a redox mediator for bio-reduction of Cr(VI): Promotor or inhibitor? THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 859:159896. [PMID: 36336043 DOI: 10.1016/j.scitotenv.2022.159896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Revised: 10/17/2022] [Accepted: 10/29/2022] [Indexed: 06/16/2023]
Abstract
Slow reduction rate and low reduction ability were the main limitations of bio-reduction of Cr(VI). As an efficient redox mediator, how phosphomolybdic acid (PMo12) affected bio-reduction of Cr(VI) was worthy of exploration. In this study, short-term and long-term effects of PMo12 on Cr(VI) reduction were investigated to reveal the relevant mechanism. After evaluating the short-term effect of PMo12 concentration from 0.05 to 1.00 mM on Cr(VI) bio-reduction, 0.50 mM was found to be optimum by improving Cr(VI) reduction rate by 16.3 % and microbial electron transport system activity (ETSA) by 43.0 % with Cr(VI) reduction efficiency of 100 % in short-term (22 h) batch experiments. By contrast, in long-term (28 days) continuous flow experiments, 0.50 mM PMo12 exhibited serious inhibition on Cr(VI) bio-reduction. The cumulative toxicity of Mo, strong oxidative stress (reactive oxygen species increased by 16.5 %), the inhibition of extracellular polymeric substances production and the reduction of microbial activity were proved to be the main inhibition mechanism. In terms of microbial electron transport system, the main electron carriers including flavin mononucleotide (FMN), nitrate reductase (NAR), nitrite reductase (NIR) were seriously inhibited. BugBase analysis confirmed that the relative abundance of biofilm forming bacteria decreased after PMo12 addition, and the relative abundance of oxidative stress tolerance bacteria continued to increase.
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Affiliation(s)
- Yingxin Zhao
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China.
| | - Xvlong Jia
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China
| | - Qian Wang
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China
| | - Yichen Wu
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China
| | - Zichen Jia
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China
| | - Xu Zhou
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China
| | - Min Ji
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China
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46
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Shen J, Liu Y, Qiao L. Photodriven Chemical Synthesis by Whole-Cell-Based Biohybrid Systems: From System Construction to Mechanism Study. ACS APPLIED MATERIALS & INTERFACES 2023; 15:6235-6259. [PMID: 36702806 DOI: 10.1021/acsami.2c19528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
By simulating natural photosynthesis, the desirable high-value chemical products and clean fuels can be sustainably generated with solar energy. Whole-cell-based photosensitized biohybrid system, which innovatively couples the excellent light-harvesting capacity of semiconductor materials with the efficient catalytic ability of intracellular biocatalysts, is an appealing interdisciplinary creature to realize photodriven chemical synthesis. In this review, we summarize the constructed whole-cell-based biohybrid systems in different application fields, including carbon dioxide fixation, nitrogen fixation, hydrogen production, and other chemical synthesis. Moreover, we elaborate the charge transfer mechanism studies of representative biohybrids, which can help to deepen the current understanding of the synergistic process between photosensitizers and microorganisms, and provide schemes for building novel biohybrids with less electron transfer resistance, advanced productive efficiency, and functional diversity. Further exploration in this field has the prospect of making a breakthrough on the biotic-abiotic interface that will provide opportunities for multidisciplinary research.
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Affiliation(s)
- Jiayuan Shen
- Department of Chemistry, and Shanghai Stomatological Hospital, Fudan University, Shanghai 200000, China
| | - Yun Liu
- Department of Chemistry, and Shanghai Stomatological Hospital, Fudan University, Shanghai 200000, China
| | - Liang Qiao
- Department of Chemistry, and Shanghai Stomatological Hospital, Fudan University, Shanghai 200000, China
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47
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Glass JB, Elbon CE, Williams LD. Something old, something new, something borrowed, something blue: the anaerobic microbial ancestry of aerobic respiration. Trends Microbiol 2023; 31:135-141. [PMID: 36058785 DOI: 10.1016/j.tim.2022.08.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 08/07/2022] [Accepted: 08/09/2022] [Indexed: 01/27/2023]
Abstract
Aerobic respiration evolved by bricolage, with modules cobbled together as microbial biochemistry coevolved with Earth's geochemistry. The mitochondrial electron transport chain represents a patchwork of respiratory modules inherited from microbial methanogenesis, iron oxidation, anoxygenic photosynthesis, and denitrification pathways, and preserves a biochemical record of Earth's redox environment over its four-billion-year history. Imprints of the anoxic early Earth are recognizable in Complex I's numerous iron-sulfur cofactors and vestigial binding sites for ferredoxin, nickel-iron, and molybdopterin, whereas the more recent advent of oxygen as a terminal electron acceptor necessitated use of heme and copper cofactors by Complex IV. Bricolage of respiratory complexes resulted in supercomplexes for improved electron transfer efficiency in some bacteria and archaea, and in many eukaryotes. Accessory subunits evolved to wrap mitochondrial supercomplexes for improved assembly and stability. Environmental microbes with 'fossil' proteins that are similar to ancestral forms of the respiratory complexes deserve further scrutiny and may reveal new insights on the evolution of aerobic respiration.
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Affiliation(s)
- Jennifer B Glass
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USA.
| | - Claire E Elbon
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Loren Dean Williams
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, USA
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48
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Hennes M, Bender N, Cronenberg T, Welker A, Maier B. Collective polarization dynamics in bacterial colonies signify the occurrence of distinct subpopulations. PLoS Biol 2023; 21:e3001960. [PMID: 36652440 PMCID: PMC9847958 DOI: 10.1371/journal.pbio.3001960] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 12/15/2022] [Indexed: 01/19/2023] Open
Abstract
Membrane potential in bacterial systems has been shown to be dynamic and tightly related to survivability at the single-cell level. However, little is known about spatiotemporal patterns of membrane potential in bacterial colonies and biofilms. Here, we discovered a transition from uncorrelated to collective dynamics within colonies formed by the human pathogen Neisseria gonorrhoeae. In freshly assembled colonies, polarization is heterogeneous with instances of transient and uncorrelated hyper- or depolarization of individual cells. As colonies reach a critical size, the polarization behavior transitions to collective dynamics: A hyperpolarized shell forms at the center, travels radially outward, and halts several micrometers from the colony periphery. Once the shell has passed, we detect an influx of potassium correlated with depolarization. Transient hyperpolarization also demarks the transition from volume to surface growth. By combining simulations and the use of an alternative electron acceptor for the respiratory chain, we provide strong evidence that local oxygen gradients shape the collective polarization dynamics. Finally, we show that within the hyperpolarized shell, tolerance against aminoglycoside antibiotics increases. These findings highlight that the polarization pattern can signify the differentiation into distinct subpopulations with different growth rates and antibiotic tolerance.
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Affiliation(s)
- Marc Hennes
- Institute for Biological Physics, and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
- * E-mail: (MH); (BM)
| | - Niklas Bender
- Institute for Biological Physics, and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Tom Cronenberg
- Institute for Biological Physics, and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Anton Welker
- Institute for Biological Physics, and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Berenike Maier
- Institute for Biological Physics, and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
- * E-mail: (MH); (BM)
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49
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Ding K, Xu L, Chen Y, Li W, Chai X, Dai X, Wu B. Mechanistic insights into polyhydroxyalkanoate-enhanced denitrification capacity of microbial community: Evolution of community structure and intracellular electron transfer of nitrogen metabolism. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 856:159147. [PMID: 36183769 DOI: 10.1016/j.scitotenv.2022.159147] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Revised: 09/27/2022] [Accepted: 09/27/2022] [Indexed: 06/16/2023]
Abstract
Denitrification is the key driving force of nitrogen cycle in surface water and plays an important role in eutrophication water remediation. Compared with some other common carbon sources, such as glucose and sodium acetate, polyhydroxyalkanoates (PHAs) were found to have the distinguished advantages in screening specific denitrifying bacteria of natural surface water bodies. In this study, the large ensembles of taxa were obtained from surface water samples and then sub-cultured with PHA or glucose as the sole carbon source. The microbial community that could be screened by PHA was identified, and the environmental functions of these bacteria were analyzed. At the genus level, the main communities regulated by PHA included Pseudomonas (56.30 %), Acinetobacter (27.75 %), Flavobacterium (10.19 %) and Comamonas (3.14 %), which all had good denitrification ability. The changes in carbon source, nitrogen source and biomass (expressed by DNA) were simultaneously monitored when culturing the model strain (P. stuzeri) with PHA or glucose. Compared with the glucose group, less PHA was consumed to remove the same amount of nitrate within a shorter incubation time, and there was no significant difference in bacterial growth with PHA or glucose as the carbon source (glucose:ΔN:ΔC:ΔDNA = 1:18:0.072; PHA:ΔN:ΔC:ΔDNA = 1:11:0.063). PHA improved the denitrification efficiency by increasing the expression of NarGHI, NirB, NirK and NorB, i.e., the key enzymes in the denitrification process. In addition, PHA accelerated the assimilating rate of extracellular nitrate by bacteria through increasing the expression of NarK. Finally, PHA-regulated electron transfer during denitrification was studied by observing the changes in NADH and NAD+. PHA could use a large proportion of NADH to offer electrons for denitrification, which increased the rate of denitrification. Improved mechanistic insights into the PHA-enhanced denitrification capacity of the microbial community can provide novel options for the in-situ remediation of eutrophic surface water.
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Affiliation(s)
- Ke Ding
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Linge Xu
- Hydrochina Huadong Engineering Corporation Limited, 201 Gaojiao Road, Hangzhou, 311122, China
| | - Yulin Chen
- Shanghai Municipal Engineering Design Institute (Group) Co., Ltd, 901 Zhongshan North 2nd Road, Shanghai 200092, China
| | - Wenxuan Li
- NUS Environmental Research Institute, National University of Singapore, 5A Engineering Drive 1, #02-01 T-Lab Building, 117411 Singapore, Singapore
| | - Xiaoli Chai
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Xiaohu Dai
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Boran Wu
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
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50
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Shi LD, Gao TY, Wei XW, Shapleigh JP, Zhao HP. pH-Dependent Hydrogenotrophic Denitratation Based on Self-Alkalization. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:685-696. [PMID: 36408861 DOI: 10.1021/acs.est.2c05559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Producing stable nitrite is a necessity for anaerobic ammonium oxidation (anammox) but remains a huge challenge. Here, we describe the design and operation of a hydrogenotrophic denitratation system that stably reduced >90% nitrate to nitrite under self-alkaline conditions of pH up to 10.80. Manually lowering the pH to a range of 9.00-10.00 dramatically decreased the nitrate-to-nitrite transformation ratio to <20%, showing a significant role of high pH in denitratation. Metagenomics combined with metatranscriptomics indicated that six microorganisms, including a Thauera member, dominated the community and encoded the various genes responsible for hydrogen oxidation and the complete denitrification process. During denitratation at high pH, transcription of periplasmic genes napA, nirS, and nirK, whose products perform nitrate and nitrite reduction, decreased sharply compared to that under neutral conditions, while narG, encoding a membrane-associated nitrate reductase, remained transcriptionally active, as were genes involved in intracellular proton homeostasis. Together with no reduction in only nitrite-amended samples, these results disproved the electron competition between reductions of nitrate and nitrite but highlighted a lack of protons outside cells constraining biological nitrite reduction. Overall, our study presents a stably efficient strategy for nitrite production and provides a major advance in the understanding of denitratation.
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Affiliation(s)
- Ling-Dong Shi
- MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou310058, Zhejiang, China
| | - Tian-Yu Gao
- MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou310058, Zhejiang, China
| | - Xiao-Wen Wei
- MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou310058, Zhejiang, China
| | - James P Shapleigh
- Department of Microbiology, Cornell University, Ithaca, New York14853, United States
| | - He-Ping Zhao
- MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou310058, Zhejiang, China
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