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Wang Y, Bai Y, Su J, Xu L, Ren Y, Ren M, Hou C, Cao M. Enhanced denitrification and p-nitrophenol removal performance via hydrophilic sponge carriers fixed with dual-bacterial: Optimization, performance, and enhancement mechanism. JOURNAL OF HAZARDOUS MATERIALS 2024; 475:134922. [PMID: 38885589 DOI: 10.1016/j.jhazmat.2024.134922] [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: 04/03/2024] [Revised: 05/18/2024] [Accepted: 06/13/2024] [Indexed: 06/20/2024]
Abstract
Effective treatment of industrial wastewater containing complex pollutants, such as nitrate (NO3--N) and organic pollutants, remains a significant challenge to date. Here, a strain Nocardioides sp. ZS2 with denitrification and degradation of p-nitrophenol (PNP) was isolated and its culture conditions were optimized by kinetic analysis. Hydrophilic sponge carriers were prepared using polyvinyl alcohol (PVA), carboxymethyl cellulose (CMC), and chitosan (CS) to construct bioreactors. Furthermore, to further enhance the PNP degradation and denitrification performance of bioreactors, Pseudomonas stutzeri GF2 with denitrification capability was introduced. The results revealed that the removal efficiencies of PNP and NO3--N reached 97.9 % and 91.9 %, respectively, when hydraulic retention time (HRT) of 6 h, C/N of 2.0, and pH of 6.5. The bioreactor exhibited stable denitrification performance even with fluctuations in the influent PNP concentration. The potential functional prediction results revealed that the abundance of amino acids, fatty acids, and carbohydrates increased as the influent C/N decreased, reflecting a tendency of the microbial community to adjust carbon source utilization to maintain cell growth, metabolic balance, and resist adverse C/N environments. This research provides new insights into the effective removal of organic pollutants and NO3--N in wastewater treatment.
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Affiliation(s)
- Yue Wang
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Yihan Bai
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Junfeng Su
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
| | - Liang Xu
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Yi Ren
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Miqi Ren
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Chenxi Hou
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Meng Cao
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
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2
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Pan Y, Hua TW, Sun RZ, Fu YY, Xiao ZC, Wang J, Yu HQ. Machine Learning-Assisted Optimization of Mixed Carbon Source Compositions for High-Performance Denitrification. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:12498-12508. [PMID: 38900106 DOI: 10.1021/acs.est.4c01743] [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: 06/21/2024]
Abstract
Appropriate mixed carbon sources have great potential to enhance denitrification efficiency and reduce operational costs in municipal wastewater treatment plants (WWTPs). However, traditional methods struggle to efficiently select the optimal mixture due to the variety of compositions. Herein, we developed a machine learning-assisted high-throughput method enabling WWTPs to rapidly identify and optimize mixed carbon sources. Taking a local WWTP as an example, a mixed carbon source denitrification data set was established via a high-throughput method and employed to train a machine learning model. The composition of carbon sources and the types of inoculated sludge served as input variables. The XGBoost algorithm was employed to predict the total nitrogen removal rate and microbial growth, thereby aiding in the assessment of the denitrification potential. The predicted carbon sources exhibited an enhanced denitrification potential over single carbon sources in both kinetic experiments and long-term reactor operations. Model feature analysis shows that the cumulative effect and interaction among individual carbon sources in a mixture significantly enhance the overall denitrification potential. Metagenomic analysis reveals that the mixed carbon sources increased the diversity and complexity of denitrifying bacterial ecological networks in WWTPs. This work offers an efficient method for WWTPs to optimize mixed carbon source compositions and provides new insights into the mechanism behind enhanced denitrification under a supply of multiple carbon sources.
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Affiliation(s)
- Yuan Pan
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Tian-Wei Hua
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Rui-Zhe Sun
- School of Resources & Environmental Engineering, Hefei University of Technology, Hefei 230009, China
| | - Ying-Ying Fu
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Zhi-Chao Xiao
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Jin Wang
- School of Resources & Environmental Engineering, Hefei University of Technology, Hefei 230009, China
| | - Han-Qing Yu
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
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3
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Chen YC, Destouches L, Cook A, Fedorec AJH. Synthetic microbial ecology: engineering habitats for modular consortia. J Appl Microbiol 2024; 135:lxae158. [PMID: 38936824 DOI: 10.1093/jambio/lxae158] [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: 04/27/2024] [Revised: 06/13/2024] [Accepted: 06/26/2024] [Indexed: 06/29/2024]
Abstract
Microbiomes, the complex networks of micro-organisms and the molecules through which they interact, play a crucial role in health and ecology. Over at least the past two decades, engineering biology has made significant progress, impacting the bio-based industry, health, and environmental sectors; but has only recently begun to explore the engineering of microbial ecosystems. The creation of synthetic microbial communities presents opportunities to help us understand the dynamics of wild ecosystems, learn how to manipulate and interact with existing microbiomes for therapeutic and other purposes, and to create entirely new microbial communities capable of undertaking tasks for industrial biology. Here, we describe how synthetic ecosystems can be constructed and controlled, focusing on how the available methods and interaction mechanisms facilitate the regulation of community composition and output. While experimental decisions are dictated by intended applications, the vast number of tools available suggests great opportunity for researchers to develop a diverse array of novel microbial ecosystems.
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Affiliation(s)
- Yue Casey Chen
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, UK
| | - Louie Destouches
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, UK
| | - Alice Cook
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, UK
| | - Alex J H Fedorec
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, UK
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4
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Saghaï A, Hallin S. Diversity and ecology of NrfA-dependent ammonifying microorganisms. Trends Microbiol 2024; 32:602-613. [PMID: 38462391 DOI: 10.1016/j.tim.2024.02.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 02/11/2024] [Accepted: 02/13/2024] [Indexed: 03/12/2024]
Abstract
Nitrate ammonifiers are a taxonomically diverse group of microorganisms that reduce nitrate to ammonium, which is released, and thereby contribute to the retention of nitrogen in ecosystems. Despite their importance for understanding the fate of nitrate, they remain a largely overlooked group in the nitrogen cycle. Here, we present the latest advances on free-living microorganisms using NrfA to reduce nitrite during ammonification. We describe their diversity and ecology in terrestrial and aquatic environments, as well as the environmental factors influencing the competition for nitrate with denitrifiers that reduce nitrate to gaseous nitrogen species, including the greenhouse gas nitrous oxide (N2O). We further review the capacity of ammonifiers for other redox reactions, showing that they likely play multiple roles in the cycling of elements.
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Affiliation(s)
- Aurélien Saghaï
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Sara Hallin
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
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Cheng Y, Ding J, Wan J, Tang L, Joseph A, Usman M, Zhu N, Zhang Y, Sun H, Rene ER, Lendvay M, Li Y. Improvement of biotic nitrate reduction in constructed photoautotrophic biofilm-soil microbial fuel cells. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 360:121066. [PMID: 38744202 DOI: 10.1016/j.jenvman.2024.121066] [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: 12/05/2023] [Revised: 03/24/2024] [Accepted: 04/29/2024] [Indexed: 05/16/2024]
Abstract
The biotic nitrate reduction rate in freshwater ecosystems is typically constrained by the scarcity of carbon sources. In this study, 'two-chambers' - 'two-electrodes' photoautotrophic biofilm-soil microbial fuel cells (P-SMFC) was developed to accelerate nitrate reduction by activating in situ electron donors that originated from the soil organic carbon (SOC). The nitrate reduction rate of P-SMFC (0.1341 d-1) improved by ∼ 1.6 times on the 28th day compared to the control photoautotrophic biofilm. The relative abundance of electroactive bacterium increased in the P-SMFC and this bacterium contributed to obtain electrons from SOC. Biochar amendment decreased the resistivity of P-SMFC, increased the electron transferring efficiency, and mitigated anodic acidification, which continuously facilitated the thriving of putative electroactive bacterium and promoted current generation. The results from physiological and ecological tests revealed that the cathodic photoautotrophic biofilm produced more extracellular protein, increased the relative abundance of Lachnospiraceae, Magnetospirillaceae, Pseudomonadaceae, and Sphingomonadaceae, and improved the activity of nitrate reductase and ATPase. Correspondingly, P-SMFC in the presence of biochar achieved the highest reaction rate constant for nitrate reduction (kobs) (0.2092 d-1) which was 2.4 times higher than the control photoautotrophic biofilm. This study provided a new strategy to vitalize in situ carbon sources in paddy soil for nitrate reduction by the construction of P-SMFC.
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Affiliation(s)
- Yu Cheng
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China
| | - Jue Ding
- School of Geographical Sciences, Jiangsu Second Normal University, Nanjing, 211200, China.
| | - Jiahui Wan
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China
| | - Li Tang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China
| | - Akaninyene Joseph
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China
| | - Muhammad Usman
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China
| | - Ningyuan Zhu
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China; Institute of Soil Sciences, Chinese Academy of Sciences, 71 East Beijing Road, Nanjing, 210008, China.
| | - Yanxia Zhang
- Jiangsu Surveying And Design Institute Of Water Resources Company Limited, Yangzhou, Jiangsu Province, 210096, China
| | - Han Sun
- Jiangsu Surveying And Design Institute Of Water Resources Company Limited, Yangzhou, Jiangsu Province, 210096, China
| | - Eldon R Rene
- Department of Water Supply, Sanitation and Environmental Engineering, IHE Delft Institute for Water Education, Westvest 7, 2611AX, Delft, the Netherlands
| | - Marton Lendvay
- Department of Geography and Earth Sciences, Aberystwyth University, Aberystwyth, SY233DB, United Kingdom
| | - Yiping Li
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China
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Lee KK, Liu S, Crocker K, Huggins DR, Tikhonov M, Mani M, Kuehn S. Functional regimes define the response of the soil microbiome to environmental change. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.15.584851. [PMID: 38559185 PMCID: PMC10980070 DOI: 10.1101/2024.03.15.584851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
The metabolic activity of soil microbiomes plays a central role in carbon and nitrogen cycling. Given the changing climate, it is important to understand how the metabolism of natural communities responds to environmental change. However, the ecological, spatial, and chemical complexity of soils makes understanding the mechanisms governing the response of these communities to perturbations challenging. Here, we overcome this complexity by using dynamic measurements of metabolism in microcosms and modeling to reveal regimes where a few key mechanisms govern the response of soils to environmental change. We sample soils along a natural pH gradient, construct >1500 microcosms to perturb the pH, and quantify the dynamics of respiratory nitrate utilization, a key process in the nitrogen cycle. Despite the complexity of the soil microbiome, a minimal mathematical model with two variables, the quantity of active biomass in the community and the availability of a growth-limiting nutrient, quantifies observed nitrate utilization dynamics across soils and pH perturbations. Across environmental perturbations, changes in these two variables give rise to three functional regimes each with qualitatively distinct dynamics of nitrate utilization over time: a regime where acidic perturbations induce cell death that limits metabolic activity, a nutrient-limiting regime where nitrate uptake is performed by dominant taxa that utilize nutrients released from the soil matrix, and a resurgent growth regime in basic conditions, where excess nutrients enable growth of initially rare taxa. The underlying mechanism of each regime is predicted by our interpretable model and tested via amendment experiments, nutrient measurements, and sequencing. Further, our data suggest that the long-term history of environmental variation in the wild influences the transitions between functional regimes. Therefore, quantitative measurements and a mathematical model reveal the existence of qualitative regimes that capture the mechanisms and dynamics of a community responding to environmental change.
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Affiliation(s)
- Kiseok Keith Lee
- Department of Ecology and Evolution, The University of Chicago, Chicago, IL 60637, USA
- Center for the Physics of Evolving Systems, The University of Chicago, Chicago, IL 60637, USA
- Center for Living Systems, The University of Chicago, Chicago, IL 60637, USA
| | - Siqi Liu
- Department of Engineering Sciences and Applied Mathematics, Northwestern University, Evanston, IL 60208, USA
| | - Kyle Crocker
- Department of Ecology and Evolution, The University of Chicago, Chicago, IL 60637, USA
- Center for the Physics of Evolving Systems, The University of Chicago, Chicago, IL 60637, USA
- Center for Living Systems, The University of Chicago, Chicago, IL 60637, USA
| | - David R. Huggins
- USDA-ARS, Northwest Sustainable Agroecosystems Research Unit, Pullman, WA 99164, USA
| | - Mikhail Tikhonov
- Department of Physics, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Madhav Mani
- Department of Engineering Sciences and Applied Mathematics, Northwestern University, Evanston, IL 60208, USA
- NSF-Simons Center for Quantitative Biology, Northwestern University, Evanston, IL 60208, USA
- National Institute for Theory and Mathematics in Biology, Northwestern University and The University of Chicago, Chicago, IL
| | - Seppe Kuehn
- Department of Ecology and Evolution, The University of Chicago, Chicago, IL 60637, USA
- Center for the Physics of Evolving Systems, The University of Chicago, Chicago, IL 60637, USA
- National Institute for Theory and Mathematics in Biology, Northwestern University and The University of Chicago, Chicago, IL
- Center for Living Systems, The University of Chicago, Chicago, IL 60637, USA
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Sayin A, Soleimanifar M, Rosenthal A, Jezek R, de Falco G, Ramalingam K, Fillos J. Evaluation of aircraft deicing fluid as an external carbon source for denitrification. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 925:171795. [PMID: 38508269 DOI: 10.1016/j.scitotenv.2024.171795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 03/04/2024] [Accepted: 03/16/2024] [Indexed: 03/22/2024]
Abstract
Water resource recovery facilities (WRRFs) performing biological nitrogen removal (BNR) often require external carbon sources for meeting nitrogen discharge permit limits. This brings an additional financial burden to the facilities considering the continuous need of these external carbon sources. This paper evaluates the utilization of airport stormwater, which in the winter season is rich in aircraft deicing fluid (ADF) as an alternative external carbon source. Denitrification and nitrification bench scale experiments were performed to assess the efficacy of external carbon sources to remove nitrogen in WRRFs. Experimental results showed that ADFs achieve denitrification rates of 0.064-0.066 d-1, higher than what achieved by a commercial carbon source, MicroC 2000A, with corresponding value of 0.058 d-1 at low temperatures, as low as 13 °C, which is considered a worst-case scenario for nitrogen removal efficiency. Furthermore, no inhibition to nitrification associated with the ADFs was observed. Subsequently a dynamic modeling study was conducted to assess the performance of ADFs as external carbon sources for denitrification and compared them to the conventional source that was being used in a full-scale BNR process. Results from the dynamic modeling study revealed that if 40 % of the spent-ADF at LaGuardia airport, New York City, could be collected with the stormwater and conveyed to a WRRF via the sewer collection system, an approximate reduction of 30 % of the commercial external carbon source could be accomplished by repurposing a waste product. This study contributes to the potential of ADF as a denitrification aid and an alternative for commercially available carbon sources with comparable nitrogen removal efficiencies.
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Affiliation(s)
- Aykut Sayin
- Department of Civil Engineering, City College of New York, New York, NY 10031, United States.
| | - Maedeh Soleimanifar
- Department of Civil Engineering, City College of New York, New York, NY 10031, United States
| | - Alex Rosenthal
- Department of Civil Engineering, City College of New York, New York, NY 10031, United States
| | - Roland Jezek
- Department of Civil Engineering, City College of New York, New York, NY 10031, United States
| | - Giacomo de Falco
- Department of Civil Engineering, City College of New York, New York, NY 10031, United States.
| | - Krish Ramalingam
- Department of Civil Engineering, City College of New York, New York, NY 10031, United States
| | - John Fillos
- Department of Civil Engineering, City College of New York, New York, NY 10031, United States
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Zou H, He J, Chu Y, Xu B, Li W, Huang S, Guan X, Liu F, Li H. Revealing discrepancies and drivers in the impact of lomefloxacin on groundwater denitrification throughout microbial community growth and succession. JOURNAL OF HAZARDOUS MATERIALS 2024; 465:133139. [PMID: 38056273 DOI: 10.1016/j.jhazmat.2023.133139] [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: 09/20/2023] [Revised: 10/31/2023] [Accepted: 11/28/2023] [Indexed: 12/08/2023]
Abstract
The coexistence of antibiotics and nitrates has raised great concern about antibiotic's impact on denitrification. However, conflicting results in these studies are very puzzling, possibly due to differences in microbial succession stages. This study investigated the effects of the high-priority urgent antibiotic, lomefloxacin (LOM), on groundwater denitrification throughout microbial growth and succession. The results demonstrated that LOM's impact on denitrification varied significantly across three successional stages, with the most pronounced effects exhibited in the initial stage (53.8% promotion at 100 ng/L-LOM, 84.6% inhibition at 100 μg/L-LOM), followed by the decline stage (13.3-18.2% inhibition), while no effect in the stable stage. Hence, a distinct pattern encompassing susceptibility, insusceptibility, and sub-susceptibility in LOM's impact on denitrification was discovered. Microbial metabolism and environment variation drove the pattern, with bacterial numbers and antibiotic resistance as primary influencers (22.5% and 15.3%, p < 0.01), followed by carbon metabolism and microbial community (5.0% and 3.68%, p < 0.01). The structural equation model confirmed results reliability. Bacterial numbers and resistance influenced susceptibility by regulating compensation and bacteriostasis, while carbon metabolism and microbial community impacted energy, electron transfer, and gene composition. These findings provide valuable insights into the complex interplay between antibiotics and denitrification patterns in groundwater.
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Affiliation(s)
- Hua Zou
- Key Laboratory of Groundwater Conservation of MWR, China University of Geosciences, Beijing 100083, China; MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences, Beijing 100083, China
| | - Jiangtao He
- Key Laboratory of Groundwater Conservation of MWR, China University of Geosciences, Beijing 100083, China; MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences, Beijing 100083, China.
| | - Yanjia Chu
- Key Laboratory of Groundwater Conservation of MWR, China University of Geosciences, Beijing 100083, China; MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences, Beijing 100083, China
| | - Baoshi Xu
- Key Laboratory of Groundwater Conservation of MWR, China University of Geosciences, Beijing 100083, China; MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences, Beijing 100083, China
| | - Wei Li
- Key Laboratory of Groundwater Conservation of MWR, China University of Geosciences, Beijing 100083, China; MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences, Beijing 100083, China
| | - Shiwen Huang
- Key Laboratory of Groundwater Conservation of MWR, China University of Geosciences, Beijing 100083, China; MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences, Beijing 100083, China
| | - Xiangyu Guan
- Key Laboratory of Groundwater Conservation of MWR, China University of Geosciences, Beijing 100083, China; School of Ocean Sciences, China University of Geosciences (Beijing), Beijing 100083, China
| | - Fei Liu
- Key Laboratory of Groundwater Conservation of MWR, China University of Geosciences, Beijing 100083, China; MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences, Beijing 100083, China
| | - Haiyan Li
- School of Environment and Energy Engineering, Beijing University of Civil Engineering and Architecture, Beijing 100044, China
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Wu Z, Yu X, Ji Y, Liu G, Gao P, Xia L, Li P, Liang B, Freilich S, Gu L, Qiao W, Jiang J. Flexible catabolism of monoaromatic hydrocarbons by anaerobic microbiota adapting to oxygen exposure. JOURNAL OF HAZARDOUS MATERIALS 2024; 462:132762. [PMID: 37837778 DOI: 10.1016/j.jhazmat.2023.132762] [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: 07/17/2023] [Revised: 09/26/2023] [Accepted: 10/10/2023] [Indexed: 10/16/2023]
Abstract
Microbe-mediated anaerobic degradation is a practical method for remediation of the hazardous monoaromatic hydrocarbons (BTEX, including benzene, toluene, ethylbenzene and xylenes) under electron-deficient contaminated sites. However, how do the anaerobic functional microbes adapt to oxygen exposure and flexibly catabolize BTEX remain poorly understood. We investigated the switches of substrate spectrum and bacterial community upon oxygen perturbation in a nitrate-amended anaerobic toluene-degrading microbiota which was dominated by Aromatoleum species. DNA-stable isotope probing demonstrated that Aromatoleum species was involved in anaerobic mineralization of toluene. Metagenome-assembled genome of Aromatoleum species harbored both the nirBD-type genes for nitrate reduction to ammonium coupled with toluene oxidation and the additional meta-cleavage pathway for aerobic benzene catabolism. Once the anaerobic microbiota was fully exposed to oxygen and benzene, 1.05 ± 0.06% of Diaphorobacter species rapidly replaced Aromatoleum species and flourished to 96.72 ± 0.01%. Diaphorobacter sp. ZM was isolated, which was not only able to utilize benzene as the sole carbon source for aerobic growth and but also innovatively reduce nitrate to ammonium with citrate/lactate/glucose as the carbon source under anaerobic conditions. This study expands our understanding of the adaptive mechanism of microbiota for environmental redox disturbance and provides theoretical guidance for the bioremediation of BTEX-contaminated sites.
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Affiliation(s)
- Zhiming Wu
- Department of Microbiology, Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture and Rural Affairs, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Xin Yu
- Department of Microbiology, Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture and Rural Affairs, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Yanhan Ji
- Department of Microbiology, Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture and Rural Affairs, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Guiping Liu
- Department of Microbiology, Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture and Rural Affairs, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Ping Gao
- Department of Microbiology, Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture and Rural Affairs, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Lei Xia
- Department of Microbiology, Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture and Rural Affairs, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Pengfa Li
- Department of Microbiology, Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture and Rural Affairs, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Bin Liang
- State Key Laboratory of Urban Water Resource and Environment, School of Civil & Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China
| | - Shiri Freilich
- Newe Ya'ar Research Center, Agricultural Research Organization, Ramat Yishay, Israel
| | - Lifeng Gu
- ChangXing AISHENG Environmental Technology Co., Ltd, Zhejiang 313199, China
| | - Wenjing Qiao
- Department of Microbiology, Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture and Rural Affairs, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China.
| | - Jiandong Jiang
- Department of Microbiology, Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture and Rural Affairs, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China.
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10
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Sun X, Tong W, Wu G, Yang G, Zhou J, Feng L. A collaborative effect of solid-phase denitrification and algae on secondary effluent purification. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 348:119393. [PMID: 37925989 DOI: 10.1016/j.jenvman.2023.119393] [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: 04/14/2023] [Revised: 10/05/2023] [Accepted: 10/11/2023] [Indexed: 11/07/2023]
Abstract
This study explored the collaborative effect on nutrients removal performance and microbial community in solid-phase denitrification based bacteria-algae symbiosis system. Three biodegradable carriers (apple wood, poplar wood and corncob) and two algae species (Chlorella vulgaris and Chlorella pyrenoidosa) were selected in these bacteria-algae symbiosis systems. Results demonstrated that corncob as the carrier exhibited the highest average removal efficiencies of total nitrogen (83.7%-85.1%) and phosphorus removal (38.1%-49.1%) in comparison with apple wood (65.8%-71.5%, 25.5%-32.7%) and poplar wood (42.5%-49.1%, 14.2%-20.7%), which was mainly attributed to the highest organics availability of corncob. The addition of Chlorella acquired approximately 3%-5% of promotion rates for nitrated removal among three biodegradable carriers, but only corncob reactor acquired significant promotions by 3%-11% for phosphorous removal. Metagenomics sequencing analysis further indicated that Proteobacteria was the largest phylum in all wood reactors (77.1%-93.3%) and corncob reactor without Chlorella (85.8%), while Chlorobi became the most dominant phylum instead of Proteobacteria (20.5%-41.3%) in the corncob with addition of Chlorella vulgaris (54.5%) and Chlorella pyrenoidosa (76.3%). Thus, the higher organics availability stimulated the growth of algae, and promoted the performance of bacteria-algae symbiosis system based biodegradable carriers.
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Affiliation(s)
- Xiaoran Sun
- Zhejiang Key Laboratory of Petrochemical Environmental Pollution Control, Zhejiang Ocean University, Zhoushan, 316022, People's Republic of China
| | - Weibing Tong
- Zhejiang Key Laboratory of Petrochemical Environmental Pollution Control, Zhejiang Ocean University, Zhoushan, 316022, People's Republic of China
| | - Guiyang Wu
- Zhejiang Key Laboratory of Petrochemical Environmental Pollution Control, Zhejiang Ocean University, Zhoushan, 316022, People's Republic of China
| | - Guangfeng Yang
- Zhejiang Key Laboratory of Petrochemical Environmental Pollution Control, Zhejiang Ocean University, Zhoushan, 316022, People's Republic of China
| | - Jiaheng Zhou
- College of Civil Engineering and Architecture, Zhejiang University of Technology, Hangzhou, 310014, People's Republic of China
| | - Lijuan Feng
- Zhejiang Key Laboratory of Petrochemical Environmental Pollution Control, Zhejiang Ocean University, Zhoushan, 316022, People's Republic of China; National & Local Joint Engineering Research Center of Harbor Oil & Gas Storage and Transportation Technology, Zhoushan, 316022, People's Republic of China.
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11
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Saghaï A, Pold G, Jones CM, Hallin S. Phyloecology of nitrate ammonifiers and their importance relative to denitrifiers in global terrestrial biomes. Nat Commun 2023; 14:8249. [PMID: 38086813 PMCID: PMC10716430 DOI: 10.1038/s41467-023-44022-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 11/28/2023] [Indexed: 12/18/2023] Open
Abstract
Nitrate ammonification is important for soil nitrogen retention. However, the ecology of ammonifiers and their prevalence compared with denitrifiers, being competitors for nitrate, are overlooked. Here, we screen 1 million genomes for nrfA and onr, encoding ammonifier nitrite reductases. About 40% of ammonifier assemblies carry at least one denitrification gene and show higher potential for nitrous oxide production than consumption. We then use a phylogeny-based approach to recruit gene fragments of nrfA, onr and denitrification nitrite reductase genes (nirK, nirS) in 1861 global terrestrial metagenomes. nrfA outnumbers the nearly negligible onr counts in all biomes, but denitrification genes dominate, except in tundra. Random forest modelling teases apart the influence of the soil C/N on nrfA-ammonifier vs denitrifier abundance, showing an effect of nitrate rather than carbon content. This study demonstrates the multiple roles nitrate ammonifiers play in nitrogen cycling and identifies factors ultimately controlling the fate of soil nitrate.
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Affiliation(s)
- Aurélien Saghaï
- Swedish University of Agricultural Sciences, Department of Forest Mycology and Plant Pathology, Uppsala, Sweden
| | - Grace Pold
- Swedish University of Agricultural Sciences, Department of Forest Mycology and Plant Pathology, Uppsala, Sweden
| | - Christopher M Jones
- Swedish University of Agricultural Sciences, Department of Forest Mycology and Plant Pathology, Uppsala, Sweden
| | - Sara Hallin
- Swedish University of Agricultural Sciences, Department of Forest Mycology and Plant Pathology, Uppsala, Sweden.
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12
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Li S, Luo Z, Wang S, Nan Q, Ji G. Denitrification fractionates N and O isotopes of nitrate following a ratio independent of carbon sources in freshwaters. Environ Microbiol 2023; 25:2404-2415. [PMID: 37503781 DOI: 10.1111/1462-2920.16468] [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: 04/11/2023] [Accepted: 07/10/2023] [Indexed: 07/29/2023]
Abstract
The stable isotope technique has been used in tracking nitrogen cycling processes, but the isotopic characteristics are influenced by environmental conditions. To better understand the variability of nitrate isotopes in nature, we investigated the influence of organic carbon sources on isotope fractionation characteristics during microbial denitrification. Denitrifying cultures were inoculated with freshwater samples and enriched with five forms of organic compounds, that is, acetate, citrate, glucose, cellobiose, and leucine. Though the isotope enrichment factors of nitrogen and oxygen (15 ε and 18 ε) changed with carbon sources, 18 ε/15 ε always followed a proportionality near 1. Genome-centred metagenomics revealed the enrichment of a few populations, such as Pseudomonas, Enterobacter, and Atlantibacter, most of which contained both NapA- and NarG-type nitrate reductases. Metatranscriptome showed that both NapA and NarG were expressed but to different extents in the enrichments. Furthermore, isotopic data collected from a deep reservoir was analysed. The results showed δ18 O- and δ15 N-nitrate did not correlate in the surface water where nitrification was active, but 18 ε/15 ε followed a proportionality of 1.05 ± 011 in deeper waters (≥ 12 m) where denitrification controlled the nitrate isotope. The independence of 18 ε/15 ε from carbon sources provides an opportunity to determine heterotrophic denitrification and helps the interpretation of nitrate isotopes in freshwaters.
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Affiliation(s)
- Shengjie Li
- Key Laboratory of Water and Sediment Sciences, Ministry of Education, Department of Environmental Engineering, Peking University, Beijing, China
- Department of Biogeochemistry, Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Zhongxin Luo
- Key Laboratory of Water and Sediment Sciences, Ministry of Education, Department of Environmental Engineering, Peking University, Beijing, China
- China Institute of Water Resources and Hydropower Research, Beijing, China
- National Research Center for Sustainable Hydropower Development, Beijing, China
| | - Shuo Wang
- Key Laboratory of Water and Sediment Sciences, Ministry of Education, Department of Environmental Engineering, Peking University, Beijing, China
| | - Qiong Nan
- Institute of Environment Pollution Control and Treatment, College of Environment and Resource Science, Zhejiang University, Hangzhou, China
| | - Guodong Ji
- Key Laboratory of Water and Sediment Sciences, Ministry of Education, Department of Environmental Engineering, Peking University, Beijing, China
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13
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Yoon S, Heo H, Han H, Song DU, Bakken LR, Frostegård Å, Yoon S. Suggested role of NosZ in preventing N 2O inhibition of dissimilatory nitrite reduction to ammonium. mBio 2023; 14:e0154023. [PMID: 37737639 PMCID: PMC10653820 DOI: 10.1128/mbio.01540-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 07/31/2023] [Indexed: 09/23/2023] Open
Abstract
IMPORTANCE Dissimilatory nitrate/nitrite reduction to ammonium (DNRA) is a microbial energy-conserving process that reduces NO3 - and/or NO2 - to NH4 +. Interestingly, DNRA-catalyzing microorganisms possessing nrfA genes are occasionally found harboring nosZ genes encoding nitrous oxide reductases, i.e., the only group of enzymes capable of removing the potent greenhouse gas N2O. Here, through a series of physiological experiments examining DNRA metabolism in one of such microorganisms, Bacillus sp. DNRA2, we have discovered that N2O may delay the transition to DNRA upon an oxic-to-anoxic transition, unless timely removed by the nitrous oxide reductases. These observations suggest a novel explanation as to why some nrfA-possessing microorganisms have retained nosZ genes: to remove N2O that may otherwise interfere with the transition from O2 respiration to DNRA.
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Affiliation(s)
- Sojung Yoon
- Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea
| | - Hokwan Heo
- Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea
| | - Heejoo Han
- Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea
| | - Dong-Uk Song
- Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea
| | - Lars R. Bakken
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Åsa Frostegård
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Sukhwan Yoon
- Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea
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14
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Zhang S, Su J, Liu S, Ren Y, Cao S. Regulating mechanism of denitrifier Comamonas sp. YSF15 in response to carbon deficiency: Based on carbon/nitrogen functions and bioaggregation. ENVIRONMENTAL RESEARCH 2023; 235:116661. [PMID: 37451570 DOI: 10.1016/j.envres.2023.116661] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 07/04/2023] [Accepted: 07/11/2023] [Indexed: 07/18/2023]
Abstract
There is an urgent demand to investigate mechanisms for the improvement of denitrification in carbon-deficient environment, which will effectively reduce the eutrophication in water bodies polluted by nitrate. In this study, denitrifying bacterium Comamonas sp. YSF15 was used to explore the differences in different carbon source concentrations, with the complete genome, metabolomics, and other detecting methods. Results showed that strain YSF15 was able to achieve efficient denitrification, with complete pathways for denitrification and central carbon metabolism. The carbon deficiency prompted the bacteria to use extracellular amino acid-like metabolites initially, to alleviate inhibition and maintain bioactivity, which also facilitated glycogen storage. The biogenic inhibitors (tautomycin, navitoclax, and glufosinate) at extremely low level potentially favored the competitiveness and intraspecific utilization of extracellular polysaccharides (PS). Optimal solutions for bioaggregation in carbon-deficient condition are achieved by regulating the hydrophobicity, and hydrogen bond in extracellular metabolites. The strategy contributes to the maintenance of bioactivity and adaptation to carbon deficiency. Overall, this study provides a new perspective on understanding the denitrification strategies in carbon-deficient environment, and helps to improve the nitrate removal in low-carbon wastewater treatment.
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Affiliation(s)
- Shuai Zhang
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, China.
| | - Junfeng Su
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, China.
| | - Shuyu Liu
- School of Environment and Chemistry Engineering, Shanghai University, Shanghai, 200444, China.
| | - Yi Ren
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, China
| | - Shumiao Cao
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, China
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15
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Carlson HK, Piya D, Moore ML, Magar RT, Elisabeth NH, Deutschbauer AM, Arkin AP, Mutalik VK. Geochemical constraints on bacteriophage infectivity in terrestrial environments. ISME COMMUNICATIONS 2023; 3:78. [PMID: 37596312 PMCID: PMC10439110 DOI: 10.1038/s43705-023-00297-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 07/26/2023] [Accepted: 08/10/2023] [Indexed: 08/20/2023]
Abstract
Lytic phages can be potent and selective inhibitors of microbial growth and can have profound impacts on microbiome composition and function. However, there is uncertainty about the biogeochemical conditions under which phage predation modulates microbial ecosystem function, particularly in terrestrial systems. Ionic strength is critical for infection of bacteria by many phages, but quantitative data is limited on the ion thresholds for phage infection that can be compared with environmental ion concentrations. Similarly, while carbon composition varies in the environment, we do not know how this variability influences the impact of phage predation on microbiome function. Here, we measured the half-maximal effective concentrations (EC50) of 80 different inorganic ions for the infection of E. coli with two canonical dsDNA and ssRNA phages, T4 and MS2, respectively. Many alkaline earth metals and alkali metals enabled lytic infection but the ionic strength thresholds varied for different ions between phages. Additionally, using a freshwater nitrate-reducing microbiome, we found that the ability of lytic phages to influence nitrate reduction end-products depended upon the carbon source as well as ionic strength. For all phage:host pairs, the ion EC50s for phage infection exceeded the ion concentrations found in many terrestrial freshwater systems. Thus, our findings support a model where phages most influence terrestrial microbial functional ecology in hot spots and hot moments such as metazoan guts, drought influenced soils, or biofilms where ion concentration is locally or transiently elevated and nutrients are available to support the growth of specific phage hosts.
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Affiliation(s)
- Hans K Carlson
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Lab, Berkeley, CA, 94720, USA.
| | - Denish Piya
- Department of Bioengineering, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Madeline L Moore
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Lab, Berkeley, CA, 94720, USA
| | - Roniya T Magar
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Lab, Berkeley, CA, 94720, USA
| | - Nathalie H Elisabeth
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Lab, Berkeley, CA, 94720, USA
| | - Adam M Deutschbauer
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Lab, Berkeley, CA, 94720, USA
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Adam P Arkin
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Lab, Berkeley, CA, 94720, USA
- Department of Bioengineering, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Vivek K Mutalik
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Lab, Berkeley, CA, 94720, USA.
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16
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White C, Antell E, Schwartz SL, Lawrence JE, Keren R, Zhou L, Yu K, Zhuang W, Alvarez-Cohen L. Synergistic interactions between anammox and dissimilatory nitrate reducing bacteria sustains reactor performance across variable nitrogen loading ratios. Front Microbiol 2023; 14:1243410. [PMID: 37637134 PMCID: PMC10450351 DOI: 10.3389/fmicb.2023.1243410] [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: 06/20/2023] [Accepted: 07/13/2023] [Indexed: 08/29/2023] Open
Abstract
Anaerobic ammonium oxidizing (anammox) bacteria are utilized for high efficiency nitrogen removal from nitrogen-laden sidestreams in wastewater treatment plants. The anammox bacteria form a variety of competitive and mutualistic interactions with heterotrophic bacteria that often employ denitrification or dissimilatory nitrate reduction to ammonium (DNRA) for energy generation. These interactions can be heavily influenced by the influent ratio of ammonium to nitrite, NH4+:NO2-, where deviations from the widely acknowledged stoichiometric ratio (1:1.32) have been demonstrated to have deleterious effects on anammox efficiency. Thus, it is important to understand how variable NH4+:NO2- ratios impact the microbial ecology of anammox reactors. We observed the response of the microbial community in a lab scale anammox membrane bioreactor (MBR) to changes in the influent NH4+:NO2- ratio using both 16S rRNA gene and shotgun metagenomic sequencing. Ammonium removal efficiency decreased from 99.77 ± 0.04% when the ratio was 1:1.32 (prior to day 89) to 90.85 ± 0.29% when the ratio was decreased to 1:1.1 (day 89-202) and 90.14 ± 0.09% when the ratio was changed to 1:1.13 (day 169-200). Over this same timespan, the overall nitrogen removal efficiency (NRE) remained relatively unchanged (85.26 ± 0.01% from day 0-89, compared to 85.49 ± 0.01% from day 89-169, and 83.04 ± 0.01% from day 169-200). When the ratio was slightly increased to 1:1.17-1:1.2 (day 202-253), the ammonium removal efficiency increased to 97.28 ± 0.45% and the NRE increased to 88.21 ± 0.01%. Analysis of 16 S rRNA gene sequences demonstrated increased relative abundance of taxa belonging to Bacteroidetes, Chloroflexi, and Ignavibacteriae over the course of the experiment. The relative abundance of Planctomycetes, the phylum to which anammox bacteria belong, decreased from 77.19% at the beginning of the experiment to 12.24% by the end of the experiment. Analysis of metagenome assembled genomes (MAGs) indicated increased abundance of bacteria with nrfAH genes used for DNRA after the introduction of lower influent NH4+:NO2- ratios. The high relative abundance of DNRA bacteria coinciding with sustained bioreactor performance indicates a mutualistic relationship between the anammox and DNRA bacteria. Understanding these interactions could support more robust bioreactor operation at variable nitrogen loading ratios.
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Affiliation(s)
- Christian White
- Department of Civil & Environmental Engineering, University of California, Berkeley, Berkeley, CA, United States
| | - Edmund Antell
- Department of Civil & Environmental Engineering, University of California, Berkeley, Berkeley, CA, United States
| | - Sarah L. Schwartz
- Department of Civil & Environmental Engineering, University of California, Berkeley, Berkeley, CA, United States
| | | | - Ray Keren
- Department of Civil & Environmental Engineering, University of California, Berkeley, Berkeley, CA, United States
| | - Lijie Zhou
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, China
| | - Ke Yu
- School of Environment and Energy, Shenzhen Graduate School, Peking University, Shenzhen, China
| | - Weiqin Zhuang
- Department of Civil & Environmental Engineering, University of Auckland, Auckland, New Zealand
| | - Lisa Alvarez-Cohen
- Department of Civil & Environmental Engineering, University of California, Berkeley, Berkeley, CA, United States
- Earth and Environmental Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
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17
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Shi Z, Yang Y, Fan Y, He Y, Li T. Dynamic Responses of Rhizosphere Microorganisms to Biogas Slurry Combined with Chemical Fertilizer Application during the Whole Life Cycle of Rice Growth. Microorganisms 2023; 11:1755. [PMID: 37512927 PMCID: PMC10386682 DOI: 10.3390/microorganisms11071755] [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: 05/19/2023] [Revised: 06/14/2023] [Accepted: 07/01/2023] [Indexed: 07/30/2023] Open
Abstract
Biogas slurry combined with chemical fertilizer (BCF) is widely used as a fertilizer in paddy fields and rhizosphere microorganisms are key players in plant growth and reproduction. However, the dynamic responses of rhizosphere microorganisms of field-grown rice to BCF application still remain largely unknown. In this study, a field experiment was conducted in two proximate paddy fields in Chongming Island to study the impacts of BCF on the changes in rhizosphere microorganisms during the whole rice growth, including seedling, tillering, booting, and grain-filling stages, with solely chemical fertilizer (CF) treatment as control. The results showed BCF could increase the N-, P-, and C- levels in paddy water as well as the rhizosphere microbial abundance and diversity compared with control. In particular, the phosphate-solubilizing- and cellulose-decomposing-bacteria (e.g., Bacillus) and fungi (e.g., Mortierella) were more abundant in the rhizosphere of BCF than those of CF. Moreover, these microbes increased markedly at the booting and grain-filling stages in BCF, which could promote rice to obtain available nutrients (P and C). It was noted that denitrifying-like bacteria (e.g., Steroidobacteraceae) decreased and dissimilatory nitrate reduction to ammonia-related bacteria (e.g., Geobacter, Anaeromyxobacter, and Ignavibacterium) increased at the booting and filling stages, which could promote N-availability. TP in paddy water of BCF was most correlated to the bacteria, while COD was the most critical regulator for the fungi. Furthermore, correlation network analysis showed nutrient-cycling-related microorganisms were more closely interconnected in BCF than those in CF. These findings showed the application of biogas slurry plus chemical fertilizer could regulate rhizosphere microorganisms towards a beneficial fertilizer use for rice growth.
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Affiliation(s)
- Zhenbao Shi
- State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China
| | - Yanmei Yang
- Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, Institute of Eco-Chongming, East China Normal University, Shanghai 200241, China
| | - Yehong Fan
- Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, Institute of Eco-Chongming, East China Normal University, Shanghai 200241, China
| | - Yan He
- Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, Institute of Eco-Chongming, East China Normal University, Shanghai 200241, China
| | - Tian Li
- State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China
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18
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Kurtz BE, Landmeyer JE, Culter JK. Precipitation, submarine groundwater discharge of nitrogen, and red tides along the southwest Florida Gulf coast. Heliyon 2023; 9:e16046. [PMID: 37215903 PMCID: PMC10196494 DOI: 10.1016/j.heliyon.2023.e16046] [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: 10/14/2022] [Revised: 04/05/2023] [Accepted: 05/03/2023] [Indexed: 05/24/2023] Open
Abstract
Blooms of the dinoflagellate Karenia brevis occur almost every year along the southwest Florida Gulf coast. Long-duration blooms with especially high concentrations of K. brevis, known as red tides, destroy marine life through production of neurotoxins. Current hypotheses are that red tides originate in oligotrophic waters far offshore using nitrogen (N) from upwelling bottom water or, alternatively, from blooms of Trichodesmium, followed by advection to nearshore waters. But the amount of N available from terrestrial sources does not appear to be adequate to maintain a nearshore red tide. To explain this discrepancy, we hypothesize that contemporary red tides are associated with release of N from offshore submarine groundwater discharge (SGD) that has accumulated in benthic sediment biomass by dissimilatory nitrate reduction to ammonium (DNRA). The release occurs when sediment labile organic carbon (LOC), used as the electron donor in DNRA, is exhausted. Detritus from the resulting destruction of marine life restores the sediment LOC to continue the cycle of red tides. The severity of individual red tides increases with increased bloom-year precipitation in the geographic region where the SGD originates, while the severity of ordinary blooms is relatively unaffected.
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Affiliation(s)
- Bruce E. Kurtz
- New College of Florida, 5800 Bay Shore Rd., Sarasota, FL 34243, USA
| | | | - James K. Culter
- Mote Marine Laboratory, 1600 Ken Thompson Pkwy, Sarasota, FL 34236, USA
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19
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Wang Z, Hu X, Kang W, Qu Q, Feng R, Mu L. Interactions between dissolved organic matter and the microbial community are modified by microplastics and heat waves. JOURNAL OF HAZARDOUS MATERIALS 2023; 448:130868. [PMID: 36709740 DOI: 10.1016/j.jhazmat.2023.130868] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 01/08/2023] [Accepted: 01/24/2023] [Indexed: 06/18/2023]
Abstract
Dissolved organic matter (DOM) exists widely in natural waters and plays an important role in river carbon cycles and greenhouse gas emissions through microbial interactions. However, information on DOM-microbe associations in response to environmental stress is limited. River environments are the main carriers of microplastic (MP) pollution, and global heat waves (HWs) are threatening river ecology. Here, through MP exposure and HW simulation experiments, we found that DOM molecular weight and aromaticity were closely related to initial microbial communities. Moreover, MP-derived DOM regulated microbial community abundance and diversity, influenced microorganism succession trajectories as deterministic factors, and competed with riverine DOM for microbial utilization. SimulatedHWs enhanced the MP-derived DOM competitive advantage and drove the microbial community to adopt a K-strategy for effective recalcitrant carbon utilization. Relative to single environmental stressor exposure, combined MP pollution and HWs led to a more unstable microbial network. This study addresses how MPs and HWs drive DOM-microbe interactions in rivers, contributes to an in-depth understanding of the fate of river DOM and microbial community succession processes, and narrows the knowledge gap in understanding carbon sinks in aquatic ecosystems influenced by human activities and climate change.
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Affiliation(s)
- Zhongwei Wang
- Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education)/Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, 300350 Tianjin, China
| | - Xiangang Hu
- Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education)/Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, 300350 Tianjin, China.
| | - Weilu Kang
- Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education)/Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, 300350 Tianjin, China
| | - Qian Qu
- Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education)/Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, 300350 Tianjin, China
| | - Ruihong Feng
- Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education)/Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, 300350 Tianjin, China
| | - Li Mu
- Tianjin Key Laboratory of Agro-Environment and Product Safety, Key Laboratory for Environmental Factors Controlling Agro-Product Quality Safety (Ministry of Agriculture and Rural Affairs), Institute of Agro-Environmental Protection, Ministry of Agriculture and Rural Affairs, 300191 Tianjin, China
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20
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Li T, Li W, Chai X, Dai X, Wu B. PHA stimulated denitrification through regulation of preferential cofactor provision and intracellular carbon metabolism at different dissolved oxygen levels by Pseudomonas stutzeri. CHEMOSPHERE 2022; 309:136641. [PMID: 36183891 DOI: 10.1016/j.chemosphere.2022.136641] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 09/08/2022] [Accepted: 09/26/2022] [Indexed: 06/16/2023]
Abstract
Denitrification, a typical biological process mediated by complex environmental factors, i.e., carbon sources and dissolved oxygen (DO), has attracted great attention due to its contribution to the control of eutrophication and the biochemical cycling of nitrogen. However, the effects of carbon source on electron distribution and enzyme expression for enhanced denitrification under competition of electron acceptors (DO and nitrate) remain unclear. Here, we profile the carbon metabolic pathway of polyhydroxybutyrate (PHB) and glucose (Glu) at high and low DO levels (50% and 10% saturated DO, respectively). It was found that PHB enhanced the growth of Pseudomonas stutzeri (model denitrifying bacterium) and improved the specific nitrogen removal rate (SNRR) at all DO levels. The functional proteins had a better affinity for the cofactor nicotinamide-adenine dinucleotide (NADH) than for nicotinamide adenine dinucleotide phosphate (NADPH); thus, more electrons were involved in nitrogen reduction and intracellular PHB production in the PHB groups than in the Glu groups. Furthermore, the expression difference of enzymes in glucose and PHB metabolism was demonstrated by metaproteomic and target protein analysis, implying that PHB-driven intracellular carbon accumulation could optimize the intracellular electron allocation and correspondingly promote nitrogen metabolism. Our work integrated the mechanisms of intracellular carbon metabolism with preferences for electron transfer pathways in denitrification, providing a new perspective on how the selective parameters regulated microbial functions involved in denitrification.
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Affiliation(s)
- Tingting Li
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping 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
| | - 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.
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21
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Li S, Diao M, Wang S, Zhu X, Dong X, Strous M, Ji G. Distinct oxygen isotope fractionations driven by different electron donors during microbial nitrate reduction in lake sediments. ENVIRONMENTAL MICROBIOLOGY REPORTS 2022; 14:812-821. [PMID: 35691702 DOI: 10.1111/1758-2229.13101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 05/29/2022] [Indexed: 06/15/2023]
Abstract
Microbial nitrate reduction can be driven by organic carbon oxidation, as well as by inorganic electron donors, such as reduced forms of sulfur and iron. An apparent inverse oxygen isotope fractionation effect was observed during nitrate reduction in sediment incubations from five sampling sites of a freshwater lake, Hongze Lake, China. Incubations with organic and inorganic electron donor additions were performed. Especially, the inverse oxygen isotope effect was intensified after glucose addition, whereas the incubations with sulfide and Fe2+ showed normal fractionation factors. Nitrate reductase encoding genes, napA and narG, were analysed with metagenomics. Higher napA/narG ratios were associated with higher oxygen fractionation factors. The most abundant clade (59%) of NapA in the incubation with glucose was affiliated with Rhodocyclales. In contrast, it only accounted for 8%-9% of NapA in the incubations with sulfide and Fe2+ . Differences in nitrate reductases might explain different oxygen isotope effects. Our findings also suggested that large variance of O-nitrate isotope fractionations might have to be considered in the interpretation of natural isotope records.
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Affiliation(s)
- Shengjie Li
- Key Laboratory of Water and Sediment Sciences, Ministry of Education, Department of Environmental Engineering, Peking University, Beijing, China
- Department of Geoscience, University of Calgary, Calgary, AB, Canada
| | - Muhe Diao
- Department of Geoscience, University of Calgary, Calgary, AB, Canada
| | - Shuo Wang
- Key Laboratory of Water and Sediment Sciences, Ministry of Education, Department of Environmental Engineering, Peking University, Beijing, China
| | - Xianfang Zhu
- Key Laboratory of Water and Sediment Sciences, Ministry of Education, Department of Environmental Engineering, Peking University, Beijing, China
| | - Xiaoli Dong
- Department of Geoscience, University of Calgary, Calgary, AB, Canada
| | - Marc Strous
- Department of Geoscience, University of Calgary, Calgary, AB, Canada
| | - Guodong Ji
- Key Laboratory of Water and Sediment Sciences, Ministry of Education, Department of Environmental Engineering, Peking University, Beijing, China
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22
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Visser AN, Wankel SD, Frey C, Kappler A, Lehmann MF. Unchanged nitrate and nitrite isotope fractionation during heterotrophic and Fe(II)-mixotrophic denitrification suggest a non-enzymatic link between denitrification and Fe(II) oxidation. Front Microbiol 2022; 13:927475. [PMID: 36118224 PMCID: PMC9478938 DOI: 10.3389/fmicb.2022.927475] [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: 04/24/2022] [Accepted: 07/29/2022] [Indexed: 11/13/2022] Open
Abstract
Natural-abundance measurements of nitrate and nitrite (NOx) isotope ratios (δ15N and δ18O) can be a valuable tool to study the biogeochemical fate of NOx species in the environment. A prerequisite for using NOx isotopes in this regard is an understanding of the mechanistic details of isotope fractionation (15ε, 18ε) associated with the biotic and abiotic NOx transformation processes involved (e.g., denitrification). However, possible impacts on isotope fractionation resulting from changing growth conditions during denitrification, different carbon substrates, or simply the presence of compounds that may be involved in NOx reduction as co-substrates [e.g., Fe(II)] remain uncertain. Here we investigated whether the type of organic substrate, i.e., short-chained organic acids, and the presence/absence of Fe(II) (mixotrophic vs. heterotrophic growth conditions) affect N and O isotope fractionation dynamics during nitrate (NO3–) and nitrite (NO2–) reduction in laboratory experiments with three strains of putative nitrate-dependent Fe(II)-oxidizing bacteria and one canonical denitrifier. Our results revealed that 15ε and 18ε values obtained for heterotrophic (15ε-NO3–: 17.6 ± 2.8‰, 18ε-NO3–:18.1 ± 2.5‰; 15ε-NO2–: 14.4 ± 3.2‰) vs. mixotrophic (15ε-NO3–: 20.2 ± 1.4‰, 18ε-NO3–: 19.5 ± 1.5‰; 15ε-NO2–: 16.1 ± 1.4‰) growth conditions are very similar and fall within the range previously reported for classical heterotrophic denitrification. Moreover, availability of different short-chain organic acids (succinate vs. acetate), while slightly affecting the NOx reduction dynamics, did not produce distinct differences in N and O isotope effects. N isotope fractionation in abiotic controls, although exhibiting fluctuating results, even expressed transient inverse isotope dynamics (15ε-NO2–: –12.4 ± 1.3 ‰). These findings imply that neither the mechanisms ordaining cellular uptake of short-chain organic acids nor the presence of Fe(II) seem to systematically impact the overall N and O isotope effect during NOx reduction. The similar isotope effects detected during mixotrophic and heterotrophic NOx reduction, as well as the results obtained from the abiotic controls, may not only imply that the enzymatic control of NOx reduction in putative NDFeOx bacteria is decoupled from Fe(II) oxidation, but also that Fe(II) oxidation is indirectly driven by biologically (i.e., via organic compounds) or abiotically (catalysis via reactive surfaces) mediated processes co-occurring during heterotrophic denitrification.
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Affiliation(s)
- Anna-Neva Visser
- Aquatic and Isotope Biogeochemistry, Department of Environmental Sciences, Basel University, Basel, Switzerland
- *Correspondence: Anna-Neva Visser,
| | - Scott D. Wankel
- Stable Isotope Biogeochemistry, Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Falmouth, MA, United States
| | - Claudia Frey
- Aquatic and Isotope Biogeochemistry, Department of Environmental Sciences, Basel University, Basel, Switzerland
| | - Andreas Kappler
- Geomicrobiology, Center for Applied Geosciences, Eberhard Karls University, Tuebingen, Germany
- Cluster of Excellence: EXC 2124: Controlling Microbes to Fight Infection, Tuebingen, Germany
| | - Moritz F. Lehmann
- Aquatic and Isotope Biogeochemistry, Department of Environmental Sciences, Basel University, Basel, Switzerland
- Moritz F. Lehmann,
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23
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Li S, Jiang Z, Ji G. Effect of sulfur sources on the competition between denitrification and DNRA. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 305:119322. [PMID: 35447253 DOI: 10.1016/j.envpol.2022.119322] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 04/13/2022] [Accepted: 04/14/2022] [Indexed: 06/14/2023]
Abstract
The fate of nitrogen is controlled by the competition between nitrate reduction pathways. Denitrification removes nitrogen in the system to the atmosphere, whereas dissimilatory nitrate reduction to ammonia (DNRA) retains nitrate in the form of ammonia. Different microbes specialize in the oxidation of different electron donors, thus electron donors might influence the outcomes of the competition. Here, we investigated the fate of nitrate with five forms of sulfur as electron donors. Chemoautotrophic nitrate reduction did not continue after the passages of the enrichments with sulfide, sulfite and pyrite. Nitrate reduction rate was the highest in the enrichment with thiosulfate. Denitrification was stimulated and no DNRA was observed with thiosulfate, while both denitrification and DNRA were stimulated with elemental sulfur. Metagenomes of the enrichments were assembled and binned into ten genomes. The enriched populations with thiosulfate included Thiobacillus, Lentimicrobium, Sulfurovum and Hydrogenophaga, all of which contained genes involved in sulfur oxidation. Elemental sulfur-based DNRA was performed by Thiobacillus (with NrfA and NirB) and Nocardioides (with only NirB). Our study established a link between sulfur sources, nitrate reduction pathways and microbial populations.
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Affiliation(s)
- Shengjie Li
- Key Laboratory of Water and Sediment Sciences, Ministry of Education, Department of Environmental Engineering, Peking University, Beijing, 100871, China
| | - Zhuo Jiang
- Key Laboratory of Water and Sediment Sciences, Ministry of Education, Department of Environmental Engineering, Peking University, Beijing, 100871, China
| | - Guodong Ji
- Key Laboratory of Water and Sediment Sciences, Ministry of Education, Department of Environmental Engineering, Peking University, Beijing, 100871, China.
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24
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Gao J, Liu G, Li X, Tang M, Cao X, Zhou Y, Song C. Organic carbon quantity and composition jointly modulate the differentiation of nitrate reduction pathways in sediments of the Chinese eutrophic lake, Lake Chaohu. WATER RESEARCH 2022; 220:118720. [PMID: 35700644 DOI: 10.1016/j.watres.2022.118720] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Revised: 06/03/2022] [Accepted: 06/05/2022] [Indexed: 06/15/2023]
Abstract
Twelve sampling sites from two basins of Lake Chaohu were studied seasonally from June 2020 to April 2021 in Hefei City (China) to better understand the effect of organic carbon (C) quantity and composition on nitrate (NO3--N) reduction pathways. Serious algal bloom in the west basin of Lake Chaohu (WLC) resulted in higher organic C accumulation and NO3--N deficiency in interstitial water compared to the east basin of Lake Chaohu (ELC), jointly leading to a high C/NO3--N ratio. This triggered dissimilatory nitrate reduction to ammonium (DNRA) over denitrification in terms of higher DNRA rate, nitrogen retaining index (NRI), and nrfA gene abundance mediating DNRA. Furthermore, high oxygen-alkyl C and abundance of functional genes mediating labile organic C decomposition and DNRA suggested that the alkyl carbon-oxygen bond was responsible for DNRA induction. Different bacterial community composition and diversity involved in C and nitrogen (N) metabolism in two basins indicated that bacteria in sediments of WLC were more active in NO3--N reduction. Spearman correlation analysis showed that the less represented genera, such as Thiobacillus and Clostridium, were positively correlated with both organic C and NO3--N reduction rates, respectively. Hence, organic C composition could affect NO3--N reduction function by shaping the specific bacterial community.
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Affiliation(s)
- Junkai Gao
- College of Resources & Environment, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Guanglong Liu
- College of Resources & Environment, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Xiaowen Li
- State Key Laboratory of Freshwater Ecology and Biotechnology, Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, PR China
| | | | - Xiuyun Cao
- State Key Laboratory of Freshwater Ecology and Biotechnology, Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, PR China
| | - Yiyong Zhou
- State Key Laboratory of Freshwater Ecology and Biotechnology, Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, PR China
| | - Chunlei Song
- State Key Laboratory of Freshwater Ecology and Biotechnology, Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, PR China.
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25
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Chandrasiri S, Perera T, Dilhara A, Perera I, Mallawaarachchi V. CH-Bin: A Convex Hull Based Approach for Binning Metagenomic Contigs. Comput Biol Chem 2022; 100:107734. [DOI: 10.1016/j.compbiolchem.2022.107734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 07/12/2022] [Indexed: 11/30/2022]
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26
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He S, Song N, Yao Z, Jiang H. An assessment of the purification performance and resilience of sponge-based aerobic biofilm reactors for treating polluted urban surface waters. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:45919-45932. [PMID: 35150429 DOI: 10.1007/s11356-022-19083-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 02/02/2022] [Indexed: 06/14/2023]
Abstract
Pollutants are continuously released into surface waters, which decrease the dissolved oxygen (DO) concentration and leads to the formation of black-odorous water, especially in slow-flowing urban lakes and enclosed small ponds. In situ treatment by artificial aeration or water cycling, coupled with biofilm, can address this problem without occupying large amounts of land. In this study, we designed a novel sponge-based aerobic biofilm reactor (SABR) and evaluated its performance in purifying urban surface water under different conditions. In the urban lake water treatment, the continuous inflow results revealed that the NH4+-N and NO2--N concentrations in the effluent were stable and remained lower than 0.10 mg/L and 0.05 mg/L, respectively. Abrupt increases in the NH4+-N and NO2--N concentrations in the influent and sudden increases in the NH4+-N and NO2--N concentrations in the effluent were observed, and only 4 to 8 days were required for the concentrations to decline below 0.10 mg/L and 0.05 mg/L, respectively. Increases in the polyurethane sponge filling ratios in the SABRs can reduce the DO concentration but do not affect NH4+-N removal. When no biodegradable organic matter was present in the enclosed surface water, the degradation time of NH4+-N from 14.22 to 0.10 mg/L was only 9 days when SABRs were combined with water cycling, which was shorter than the time needed by water cycling alone (16 days), and most of the NH4+-N was converted to NO3--N. When massive amounts of biodegradable organic matter were present in the enclosed surface water, 22 days were required to remove the NH4+-N when SABRs were combined with water cycling. Our results indicated that organic matter could be used as a carbon source to eliminate the produced NO3--N in SABRs. Therefore, the newly developed bioreactor provides an effective approach for treating N-polluted urban surface waters.
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Affiliation(s)
- Shangwei He
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Na Song
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China
| | - Zongbao Yao
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China
| | - Helong Jiang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China.
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27
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Bryson SJ, Hunt KA, Stahl DA, Winkler MKH. Metagenomic Insights Into Competition Between Denitrification and Dissimilatory Nitrate Reduction to Ammonia Within One-Stage and Two-Stage Partial-Nitritation Anammox Bioreactor Configurations. Front Microbiol 2022; 13:825104. [PMID: 35547121 PMCID: PMC9083452 DOI: 10.3389/fmicb.2022.825104] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 03/30/2022] [Indexed: 11/13/2022] Open
Abstract
Anaerobic ammonia oxidizing bacteria (Anammox) are implemented in high-efficiency wastewater treatment systems operated in two general configurations; one-stage systems combine aerobic ammonia oxidizing bacteria (AOB) and Anammox within a single aerated reactor, whereas two-stage configurations separate these processes into discrete tanks. Within both configurations heterotrophic populations that perform denitrification or dissimilatory nitrate reduction to ammonia (DNRA) compete for carbon and nitrate or nitrite and can impact reactor performance because DNRA retains nitrogen in the system. Therefore, it is important to understand how selective pressures imposed by one-stage and two-stage reactor configurations impact the microbial community structure and associated nitrogen transforming functions. We performed 16S rRNA gene and metagenomic sequencing on different biomass fractions (granules, flocs, and suspended biomass) sampled from two facilities treating sludge dewatering centrate: a one-stage treatment facility (Chambers Creek, Tacoma, WA) and a two-stage system (Rotterdam, Netherlands). Similar microbial populations were identified across the different samples, but relative abundances differed between reactor configurations and biomass sources. Analysis of metagenome assembled genomes (MAGs) indicated different lifestyles for abundant heterotrophic populations. Acidobacteria, Bacteroidetes, and Chloroflexi MAGs had varying capacity for DNRA and denitrification. Acidobacteria MAGs possessed high numbers of glycosyl hydrolases and glycosyl transferases indicating a role in biomass degradation. Ignavibacteria and Phycosphaerae MAGs contributed to the greater relative abundance of DNRA associated nrf genes in the two-stage granules and contained genomic features suggesting a preference for an anoxic or microoxic niche. In the one-stage granules a MAG assigned to Burkholderiales accounted for much of the abundant denitrification genes and had genomic features, including the potential for autotrophic denitrification using reduced sulfur, that indicate an ability to adapt its physiology to varying redox conditions. Overall, the competition for carbon substrates between denitrifying and DNRA performing heterotrophs may be impacted by configuration specific selective pressures. In one-stage systems oxygen availability in the bulk liquid and the oxygen gradient within granules would provide a greater niche space for heterotrophic populations capable of utilizing both oxygen and nitrate or nitrite as terminal electron acceptors, compared to two-stage systems where a homogeneous anoxic environment would favor heterotrophic populations primarily adapted to anaerobic metabolism.
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Affiliation(s)
- Samuel J Bryson
- Department of Civil and Environmental Engineering, University of Washington, Seattle, WA, United States
| | - Kristopher A Hunt
- Department of Civil and Environmental Engineering, University of Washington, Seattle, WA, United States
| | - David A Stahl
- Department of Civil and Environmental Engineering, University of Washington, Seattle, WA, United States
| | - Mari-Karoliina H Winkler
- Department of Civil and Environmental Engineering, University of Washington, Seattle, WA, United States
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28
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Gopalakrishnappa C, Gowda K, Prabhakara KH, Kuehn S. An ensemble approach to the structure-function problem in microbial communities. iScience 2022; 25:103761. [PMID: 35141504 PMCID: PMC8810406 DOI: 10.1016/j.isci.2022.103761] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The metabolic activity of microbial communities plays a primary role in the flow of essential nutrients throughout the biosphere. Molecular genetics has revealed the metabolic pathways that model organisms utilize to generate energy and biomass, but we understand little about how the metabolism of diverse, natural communities emerges from the collective action of its constituents. We propose that quantifying and mapping metabolic fluxes to sequencing measurements of genomic, taxonomic, or transcriptional variation across an ensemble of diverse communities, either in the laboratory or in the wild, can reveal low-dimensional descriptions of community structure that can explain or predict their emergent metabolic activity. We survey the types of communities for which this approach might be best suited, review the analytical techniques available for quantifying metabolite fluxes in communities, and discuss what types of data analysis approaches might be lucrative for learning the structure-function mapping in communities from these data.
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Affiliation(s)
| | - Karna Gowda
- Department of Ecology and Evolution, University of Chicago, Chicago, IL 60637, USA
- Center for the Physics of Evolving Systems, University of Chicago, Chicago, IL 60637, USA
| | - Kaumudi H. Prabhakara
- Department of Ecology and Evolution, University of Chicago, Chicago, IL 60637, USA
- Center for the Physics of Evolving Systems, University of Chicago, Chicago, IL 60637, USA
| | - Seppe Kuehn
- Department of Ecology and Evolution, University of Chicago, Chicago, IL 60637, USA
- Center for the Physics of Evolving Systems, University of Chicago, Chicago, IL 60637, USA
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29
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Liu X, Sun R, Hu S, Zhong Y, Wu Y. Aromatic compounds releases aroused by sediment resuspension alter nitrate transformation rates and pathways during aerobic-anoxic transition. JOURNAL OF HAZARDOUS MATERIALS 2022; 424:127365. [PMID: 34879562 DOI: 10.1016/j.jhazmat.2021.127365] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 09/23/2021] [Accepted: 09/25/2021] [Indexed: 06/13/2023]
Abstract
Aromatic compounds (ACs) releases aroused by sediment resuspension would certainly change the concentrations of suspended sediment (SPS) and organic carbon, which may alter nitrate-N transformation during aerobic-anoxic transition. To prove this, three typical ACs (aniline, nitrobenzene, and methylbenzene) with different octanol-water partition coefficients (Kow) were selected to investigate the effects of ACs releases aroused by sediment resuspension on nitrate-N transformation during aerobic-anoxic transition. ACs releases aroused by sediment resuspension accelerated nitrate-N transformation and enhanced the potential for dissimilatory nitrate reduction to ammonium (DNRA), compared to that without sediment resuspension. With sediment resuspension, methylbenzene releases affected nitrate-N transformation rates and pathways more significantly than aniline and nitrobenzene releases. Microbial analysis indicated that sediment resuspension created complicated microbial co-occurrence networks and changed the associations among bacteria; dominant bacteria abundance varied with different ACs releases. Further analysis revealed that ACs distributed in SPS, which increased with logKow, indirectly affected nitrate-N transformation rates and pathways via altering dominant bacteria abundance and electron transport system activity (ETSA). Especially, ETSA, which was positively associated with ACs distributed in SPS, affected nitrate-N transformation most directly. Overall, ACs release fate played important roles in nitrate-N transformation, causing ammonia-N retention and alterations in nitrogen cycle during aerobic-anoxic transition.
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Affiliation(s)
- Xiaoyan Liu
- School of chemistry and chemical engineering, Northwestern Polytechnical University, Xi'an 710129, China
| | - Ran Sun
- School of chemistry and chemical engineering, Northwestern Polytechnical University, Xi'an 710129, China
| | - Sihai Hu
- School of chemistry and chemical engineering, Northwestern Polytechnical University, Xi'an 710129, China
| | - Yangquanwei Zhong
- School of chemistry and chemical engineering, Northwestern Polytechnical University, Xi'an 710129, China
| | - Yaoguo Wu
- School of chemistry and chemical engineering, Northwestern Polytechnical University, Xi'an 710129, China.
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30
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Li S, Liao Y, Pang Y, Dong X, Strous M, Ji G. Denitrification and dissimilatory nitrate reduction to ammonia in long-term lake sediment microcosms with iron(II). THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 807:150835. [PMID: 34627917 DOI: 10.1016/j.scitotenv.2021.150835] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 09/19/2021] [Accepted: 10/02/2021] [Indexed: 06/13/2023]
Abstract
Nitrate is an abundant pollutant in aquatic environments. Competition between the nitrate reduction processes, denitrification, which converts nitrate into nitrogen gas, and dissimilatory nitrate reduction to ammonia (DNRA), which converts nitrate into ammonia, decides whether an ecosystem removes or retains nitrogen. The presence of iron was previously reported to stimulate DNRA while sometimes inhibiting denitrification in in-situ studies, but long-term effect of iron(II) inputs on the competition is unknown. Here we inoculated long-term microcosms with sediments from two freshwater lakes. During 540 days of incubations, the microcosms with nitrate and Fe(II) additions of both lakes were able to sustain high nitrate reduction rates. Lepidocrocite was produced as a product of iron oxidation. We found both denitrification and DNRA were stimulated by nitrate and iron in the absence of external organic carbon addition. Phylogenetic analysis of denitrification genes, nirK and nirS, and DNRA genes, nirB and nrfA, was performed with metagenomic sequencing results. Enrichment was shown for reported Fe(II)-dependent nitrate reducers associated with nirS and nirB. Most of these bacteria are affiliated with Betaproteobacteria. From 16S rRNA gene analysis, Betaproteobacteria was enriched as well. In parallel, heterotrophic denitrifiers and methanotrophic DNRA archaea increased in abundance. Our results suggested heterotrophic and Fe(II)-dependent nitrate reducers both contributed to denitrification and DNRA in long-term microcosm incubations provided with iron.
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Affiliation(s)
- Shengjie Li
- Key Laboratory of Water and Sediment Sciences, Ministry of Education, Department of Environmental Engineering, Peking University, Beijing 100871, China; Department of Geoscience, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Yinhao Liao
- Key Laboratory of Water and Sediment Sciences, Ministry of Education, Department of Environmental Engineering, Peking University, Beijing 100871, China
| | - Yunmeng Pang
- Key Laboratory of Water and Sediment Sciences, Ministry of Education, Department of Environmental Engineering, Peking University, Beijing 100871, China; Collaborative Innovation Center for Advanced Nuclear Energy Technology, INET, Tsinghua University, Beijing 100084, China
| | - Xiaoli Dong
- Department of Geoscience, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Marc Strous
- Department of Geoscience, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Guodong Ji
- Key Laboratory of Water and Sediment Sciences, Ministry of Education, Department of Environmental Engineering, Peking University, Beijing 100871, China.
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31
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Qi C, Zhou Y, Suenaga T, Oba K, Lu J, Wang G, Zhang L, Yoon S, Terada A. Organic carbon determines nitrous oxide consumption activity of clade I and II nosZ bacteria: Genomic and biokinetic insights. WATER RESEARCH 2022; 209:117910. [PMID: 34920314 DOI: 10.1016/j.watres.2021.117910] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 11/20/2021] [Accepted: 11/27/2021] [Indexed: 05/21/2023]
Abstract
Harnessing nitrous oxide (N2O)-reducing bacteria is a promising strategy to reduce the N2O footprint of engineered systems. Applying a preferred organic carbon source as an electron donor accelerates N2O consumption by these bacteria. However, their N2O consumption potential and activity when fed different organic carbon species remain unclear. Here, we systematically compared the effects of various organic carbon sources on the activity of N2O-reducing bacteria via investigation of their biokinetic properties and genomic potentials. Five organic carbon sources-acetate, succinate, glycerol, ethanol, and methanol-were fed to four N2O-reducing bacteria harboring either clade I or clade II nosZ gene. Respirometric analyses were performed with four N2O-reducing bacterial strains, identifying distinct shifts in DO- and N2O-consumption biokinetics in response to the different feeding schemes. Regardless of the N2O-reducing bacteria, higher N2O consumption rates, accompanied by higher biomass yields, were obtained with acetate and succinate. The biomass yield (15.45 ± 1.07 mg-biomass mmol-N2O-1) of Azospira sp. strain I13 (clade II nosZ) observed under acetate-fed condition was significantly higher than those of Paracoccus denitrificans and Pseudomonas stutzeri, exhibiting greater metabolic efficiency. However, the spectrum of the organic carbon species utilizable to Azospira sp. strain I13 was limited, as demonstrated by the highly variable N2O consumption rates observed with different substrates. The potential to metabolize the supplemented carbon sources was investigated by genomic analysis, the results of which corroborated the N2O consumption biokinetics results. Moreover, electron donor selection had a substantial impact on how N2O consumption activities were recovered after oxygen exposure. Collectively, our findings highlight the importance of choosing appropriate electron donor additives for increasing the N2O sink capability of biological nitrogen removal systems.
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Affiliation(s)
- Chuang Qi
- College of Food Science and Engineering, Nanjing University of Finance and Economics, Nanjing 210023, China; Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka Koganei, Tokyo 184-8588, Japan
| | - Yiwen Zhou
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka Koganei, Tokyo 184-8588, Japan
| | - Toshikazu Suenaga
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka Koganei, Tokyo 184-8588, Japan; Department of Chemical Engineering, Hiroshima University, Hiroshima 739-8527, Japan; Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, 3-8-1 Harumi-cho, Fuchu, Tokyo, 185-8538, Japan
| | - Kohei Oba
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka Koganei, Tokyo 184-8588, Japan
| | - Jilai Lu
- College of Food Science and Engineering, Nanjing University of Finance and Economics, Nanjing 210023, China
| | - Guoxiang Wang
- School of Environment, Nanjing Normal University, Nanjing 210023, China; Jiangsu Engineering Lab of Water and Soil Eco-remediation, Nanjing Normal University, Nanjing 210023, China
| | - Limin Zhang
- Jiangsu Engineering Lab of Water and Soil Eco-remediation, Nanjing Normal University, Nanjing 210023, China; Green Economy Development Institute, Nanjing University of Finance and Economics, Nanjing 210023, China
| | - Sukhwan Yoon
- Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea
| | - Akihiko Terada
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka Koganei, Tokyo 184-8588, Japan; Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, 3-8-1 Harumi-cho, Fuchu, Tokyo, 185-8538, Japan.
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Gao J, Qin J, Ye F, Ding F, Liu G, Li A, Ren C, Xu Y. Constructing simplified microbial consortia to improve the key flavour compounds during strong aroma-type Baijiu fermentation. Int J Food Microbiol 2022; 369:109594. [DOI: 10.1016/j.ijfoodmicro.2022.109594] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 02/08/2022] [Accepted: 02/22/2022] [Indexed: 11/25/2022]
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Estrela S, Vila JCC, Lu N, Bajić D, Rebolleda-Gómez M, Chang CY, Goldford JE, Sanchez-Gorostiaga A, Sánchez Á. Functional attractors in microbial community assembly. Cell Syst 2022; 13:29-42.e7. [PMID: 34653368 PMCID: PMC8800145 DOI: 10.1016/j.cels.2021.09.011] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Revised: 06/02/2021] [Accepted: 09/21/2021] [Indexed: 01/21/2023]
Abstract
For microbiome biology to become a more predictive science, we must identify which descriptive features of microbial communities are reproducible and predictable, which are not, and why. We address this question by experimentally studying parallelism and convergence in microbial community assembly in replicate glucose-limited habitats. Here, we show that the previously observed family-level convergence in these habitats reflects a reproducible metabolic organization, where the ratio of the dominant metabolic groups can be explained from a simple resource-partitioning model. In turn, taxonomic divergence among replicate communities arises from multistability in population dynamics. Multistability can also lead to alternative functional states in closed ecosystems but not in metacommunities. Our findings empirically illustrate how the evolutionary conservation of quantitative metabolic traits, multistability, and the inherent stochasticity of population dynamics, may all conspire to generate the patterns of reproducibility and variability at different levels of organization that are commonplace in microbial community assembly.
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Affiliation(s)
- Sylvie Estrela
- Department of Ecology and Evolutionary Biology and Microbial Sciences Institute, Yale University, New Haven, CT 06511, USA.
| | - Jean C C Vila
- Department of Ecology and Evolutionary Biology and Microbial Sciences Institute, Yale University, New Haven, CT 06511, USA
| | - Nanxi Lu
- Department of Ecology and Evolutionary Biology and Microbial Sciences Institute, Yale University, New Haven, CT 06511, USA
| | - Djordje Bajić
- Department of Ecology and Evolutionary Biology and Microbial Sciences Institute, Yale University, New Haven, CT 06511, USA
| | - Maria Rebolleda-Gómez
- Department of Ecology and Evolutionary Biology and Microbial Sciences Institute, Yale University, New Haven, CT 06511, USA
| | - Chang-Yu Chang
- Department of Ecology and Evolutionary Biology and Microbial Sciences Institute, Yale University, New Haven, CT 06511, USA
| | - Joshua E Goldford
- Physics of Living Systems, Massachusetts Institute of Technology, Boston, MA 02139, USA
| | - Alicia Sanchez-Gorostiaga
- Department of Ecology and Evolutionary Biology and Microbial Sciences Institute, Yale University, New Haven, CT 06511, USA; Department of Microbial Biotechnology, Centro Nacional de Biotecnología, CSIC, UAM Cantoblanco, 28049 Madrid, Spain
| | - Álvaro Sánchez
- Department of Ecology and Evolutionary Biology and Microbial Sciences Institute, Yale University, New Haven, CT 06511, USA.
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Biochar and Zeolite as Alternative Biofilter Media for Denitrification of Aquaculture Effluents. WATER 2021. [DOI: 10.3390/w13192703] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Denitrification processes are crucial in aquaculture as they convert the undesirable nitrate to safer forms of nitrogen. Conventionally, plastic media are used for the biofiltration of wastewater. However, alternative media may be as effective/better than plastic and enhance the sustainability of the system. This study evaluated biochar and zeolite as alternatives for the denitrification of aquaculture effluents. Triplicates of laboratory-scale bioreactors were fabricated to compare the denitrification efficiencies of biochar and zeolite to that of plastic. The bioreactors were fed synthetic aquaculture wastewater having nitrate loading rates of 50, 125, and 150 mg/L. Zeolite exhibited highest values of surface roughness in terms of arithmetic mean height (0.89 µm), maximum height (6.52 µm), and root-mean-square height (1.17 µm), as corroborated by surface profilometry and scanning electron microscopy. The results revealed that under pseudo-steady-state conditions, zeolite displayed the highest nitrate removal efficiency (maximum 95.02 ± 0.01%), which was followed by biochar and plastic (maximum 92.91 ± 0.01% and 92.57 ± 0.02%, respectively) due to its extraordinary surface roughness that provided better adhesion to the bacteria. However, by the end of the study, all the media exhibited comparable rates. Thus, both zeolite and biochar are sustainable alternatives of biomedia for nitrate removal. However, time and labor constraints must be accounted for to scale-up such bioreactors.
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Microbial Lipopeptide-Producing Strains and Their Metabolic Roles under Anaerobic Conditions. Microorganisms 2021; 9:microorganisms9102030. [PMID: 34683351 PMCID: PMC8540375 DOI: 10.3390/microorganisms9102030] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 09/09/2021] [Accepted: 09/10/2021] [Indexed: 01/17/2023] Open
Abstract
The lipopeptide produced by microorganisms is one of the representative biosurfactants and is characterized as a series of structural analogues of different families. Thirty-four families covering about 300 lipopeptide compounds have been reported in the last decades, and most of the reported lipopeptides produced by microorganisms were under aerobic conditions. The lipopeptide-producing strains under anaerobic conditions have attracted much attention from both the academic and industrial communities, due to the needs and the challenge of their applications in anaerobic environments, such as in oil reservoirs and in microbial enhanced oil recovery (MEOR). In this review, the fifty-eight reported bacterial strains, mostly isolated from oil reservoirs and dominated by the species Bacillus subtilis, producing lipopeptide biosurfactants, and the species Pseudomonas aeruginosa, producing glycolipid biosurfactants under anaerobic conditions were summarized. The metabolic pathway and the non-ribosomal peptide synthetases (NRPSs) of the strain Bacillus subtilis under anaerobic conditions were analyzed, which is expected to better understand the key mechanisms of the growth and production of lipopeptide biosurfactants of such kind of bacteria under anaerobic conditions, and to expand the industrial application of anaerobic biosurfactant-producing bacteria.
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Sun X, Xiang J. Mechanism Underlying the Role of LuxR Family Transcriptional Regulator abaR in Biofilm Formation by Acinetobacter baumannii. Curr Microbiol 2021; 78:3936-3944. [PMID: 34522977 PMCID: PMC8439540 DOI: 10.1007/s00284-021-02654-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 09/02/2021] [Indexed: 11/26/2022]
Abstract
Our study attempted to explore the mechanism underlying the role of LuxR family transcriptional regulator abaR in biofilm formation by Acinetobacter baumannii. The abaR gene was knocked out in ATCC 17978 strain using homologous recombination method. The growth curve and biofilm formation were measured in the wild type and abaR gene knockdown strains. Transcriptome sequencing was performed in the wild type and abaR gene knockdown strains following 8 h of culture. The growth curve in the abaR gene knockdown strain was similar to that of the wild-type strain. Biofilm formation significantly declined in the abaR gene knockdown strain at 8 and 48 h after culture. A total of 137 differentially expressed genes (DEGs) were obtained including 20 downregulated DEGs and 117 upregulated DEGs. Genes with differential expression were closely related to viral procapsid maturation (GO:0046797), acetoin catabolism (GO:0045150), carbon metabolism (ko01200), and the glycolysis/gluconeogenesis (ko00010)-related pathways. The results of the eight verified expression DEGs were consistent with the results predicted by bioinformatics. AbaR gene knockdown significantly affected biofilm formation by A. baumannii ATCC 17978 strain. The glycolysis/gluconeogenesis pathways were significantly dysregulated and induced by abaR gene knockdown in A. baumannii.
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Affiliation(s)
- Xu Sun
- Department of Burn, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jun Xiang
- Department of Burn, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China.
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37
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Chen H, Tu Z, Wu S, Yu G, Du C, Wang H, Yang E, Zhou L, Deng B, Wang D, Li H. Recent advances in partial denitrification-anaerobic ammonium oxidation process for mainstream municipal wastewater treatment. CHEMOSPHERE 2021; 278:130436. [PMID: 33839386 DOI: 10.1016/j.chemosphere.2021.130436] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Revised: 03/25/2021] [Accepted: 03/27/2021] [Indexed: 05/05/2023]
Abstract
To solve the bottleneck of the unstable accumulation of nitrite in the partial nitrification (PN)-anammox (AMX) in municipal wastewater treatment, a novel process called partial denitrification (PD)-AMX has been developed. PD-AMX, which is known for cost-efficiency and environmental friendliness, has currently exhibited a promising potential for the removal of biological nitrogen from municipal wastewater and has attracted much research interest regarding its process mechanisms, as well as its practical applications. Here, we review the recent advances in the PD process and its coupling to the anammox process, including the development, basic principles, main characteristics, and critical process parameters of the stable operation of the PD-AMX process. We also explore the microbial community and its characteristics in the system and summarize the knowledge of the dominant bacteria to clarify the key factors affecting PD-AMX. Then, we introduce the engineering feasibility and economic feasibility as well as the potential challenges of the process. The induction and implementation of partial denitrification and maintenance of mainstream anammox are critical issues to be urgently solved. Meanwhile, the implementation of a full mainstream anammox application remains burdensome, while the mechanism of partial denitrification coupled to anammox needs to be further studied. Additionally, stable operation performance and process control1 methods need to be optimized or developed for the PD-AMX system for better engineering practice. This review can help to accelerate the research and application of the PD-AMX process for municipal wastewater treatment.
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Affiliation(s)
- Hong Chen
- Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, School of Hydraulic Engineering, Changsha University of Science and Technology, Changsha, 410004, China; Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, Sendai, 980-8579, Japan
| | - Zhi Tu
- Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, School of Hydraulic Engineering, Changsha University of Science and Technology, Changsha, 410004, China; College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China
| | - Sha Wu
- Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, School of Hydraulic Engineering, Changsha University of Science and Technology, Changsha, 410004, China
| | - Guanlong Yu
- Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, School of Hydraulic Engineering, Changsha University of Science and Technology, Changsha, 410004, China
| | - Chunyan Du
- Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, School of Hydraulic Engineering, Changsha University of Science and Technology, Changsha, 410004, China
| | - Hong Wang
- Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, School of Hydraulic Engineering, Changsha University of Science and Technology, Changsha, 410004, China; College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China
| | - Enzhe Yang
- Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, School of Hydraulic Engineering, Changsha University of Science and Technology, Changsha, 410004, China; School of Energy Science and Engineering, Central South University, Changsha, 410083, China
| | - Lu Zhou
- Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, School of Hydraulic Engineering, Changsha University of Science and Technology, Changsha, 410004, China
| | - Bin Deng
- Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, School of Hydraulic Engineering, Changsha University of Science and Technology, Changsha, 410004, China
| | - Dongbo Wang
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China.
| | - Hailong Li
- School of Energy Science and Engineering, Central South University, Changsha, 410083, China.
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38
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Qi H, Zhao Y, Wang X, Wei Z, Zhang X, Wu J, Xie X, Kang K, Yang H, Shi M, Su X, Zhang C, Wu Z. Manganese dioxide driven the carbon and nitrogen transformation by activating the complementary effects of core bacteria in composting. BIORESOURCE TECHNOLOGY 2021; 330:124960. [PMID: 33744737 DOI: 10.1016/j.biortech.2021.124960] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 03/03/2021] [Accepted: 03/05/2021] [Indexed: 06/12/2023]
Abstract
This study revealed core bacterial metabolic mechanisms involved in carbon (C) and nitrogen (N) in composting with adding MnO2. Two tests (control group (CK), adding MnO2 (M)) were performed. The results indicated that the MnO2 accelerated the transformation of carbon and nitrogen in composting. Core bacteria involved in the C and N conversion were identified, the complementarity effects of core bacteria were stimulated in M composting. Additionally, the influence of core bacteria on the C and N conversion could be divided into two pathways in M composting. One was that core bacteria promoted C and N conversion by accelerating the flow of amino acids into the tricarboxylic acid cycle. Another was that the complementarity effects of core bacteria increased the overall bacterial diversity, which contributed to C and N conversion. These findings showed that the addition of MnO2 to composting was a promising application to treat agricultural organic waste.
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Affiliation(s)
- Haishi Qi
- College of Life Science, Northeast Agricultural University, Harbin 150030, China
| | - Yue Zhao
- College of Life Science, Northeast Agricultural University, Harbin 150030, China
| | - Xue Wang
- College of Life Science, Northeast Agricultural University, Harbin 150030, China
| | - Zimin Wei
- College of Life Science, Northeast Agricultural University, Harbin 150030, China.
| | - Xu Zhang
- College of Life Science, Northeast Agricultural University, Harbin 150030, China
| | - Junqiu Wu
- College of Life Science, Northeast Agricultural University, Harbin 150030, China
| | - Xinyu Xie
- College of Life Science, Northeast Agricultural University, Harbin 150030, China
| | - Kejia Kang
- Heilongjiang Province Environmental Science Research Institute, Harbin 150056, China
| | - Hongyan Yang
- Heilongjiang Province Environmental Science Research Institute, Harbin 150056, China
| | - Mingzi Shi
- College of Life Science, Northeast Agricultural University, Harbin 150030, China
| | - Xinya Su
- College of Life Science, Northeast Agricultural University, Harbin 150030, China
| | - Chunhao Zhang
- College of Life Science, Northeast Agricultural University, Harbin 150030, China
| | - Zhanhai Wu
- College of Life Science, Northeast Agricultural University, Harbin 150030, China
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Shi M, Zhao Y, Zhang A, Zhao M, Zhai W, Wei Z, Song Y, Tang X, He P. Factoring distinct materials and nitrogen-related microbes into assessments of nitrogen pollution risks during composting. BIORESOURCE TECHNOLOGY 2021; 329:124896. [PMID: 33657502 DOI: 10.1016/j.biortech.2021.124896] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 02/17/2021] [Accepted: 02/20/2021] [Indexed: 06/12/2023]
Abstract
The aim of this study was to evaluate nitrogen pollution risks from distinct materials composting with the discrepancy of component, including chicken manure, municipal solid and straw waste (CM, MSW, SW). Results showed total nitrogen maximum mean concentrations were observed in CM (39.57 g/kg). Pollution risks in CM were continuous, while MSW and SW mainly concentrated during heating phases. Microbial analysis confirmed that pollution risks from ammonification and nitrification were more prevalent in CM. The risks of pollution caused by nitrate reduction accompanied N2O were the most serious in MSW. The multifunctional nitrogen-related microbes Pseudomonas and Bacillus were affected by microenvironments and contributed to different pollution risks. Furthermore, PICRUSt analysis identified the "inferred" key genes (pmoC-amoC, nrfH, nifD etc.) related to nitrogen pollution risks. This study evaluated nitrogen pollution risks and proposed the future directions, providing theoretical basis and feasible optimization measures for the mitigation of nitrogen pollution during composting.
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Affiliation(s)
- Mingzi Shi
- College of Life Science, Northeast Agricultural University, Harbin 150030, China
| | - Yue Zhao
- College of Life Science, Northeast Agricultural University, Harbin 150030, China
| | - An Zhang
- College of Life Science, Northeast Agricultural University, Harbin 150030, China
| | - Maoyuan Zhao
- College of Life Science, Northeast Agricultural University, Harbin 150030, China
| | - Wenhao Zhai
- College of Life Science, Northeast Agricultural University, Harbin 150030, China
| | - Zimin Wei
- College of Life Science, Northeast Agricultural University, Harbin 150030, China.
| | - Yangyang Song
- College of Life Science, Northeast Agricultural University, Harbin 150030, China
| | - Xiaofei Tang
- Heilongjiang Province Environmental Science Research Institute, Harbin 150056, China
| | - Pingping He
- Heilongjiang Province Environmental Science Research Institute, Harbin 150056, China
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40
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Lin Y, Wang L, Xu K, Huang H, Ren H. Algae Biofilm Reduces Microbe-Derived Dissolved Organic Nitrogen Discharges: Performance and Mechanisms. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:6227-6238. [PMID: 33891391 DOI: 10.1021/acs.est.0c06915] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Microbe-derived dissolved organic nitrogen (mDON) can readily induce harmful phytoplankton blooms, and thus, restricting its discharges is necessary. Recently, algae biofilm (AB) has attracted increasing interest for its advantages in nutrient recovery. However, its features in mDON control remain unexplored. Herein, AB's mDON formation and utilization performance, molecular characteristics, and metabolic traits have been investigated, with activated sludge (AS) as the benchmark for comparisons. Comparatively, AB reduced mDON formation by 83% when fed with DON-free wastewater. When fed with AS's effluent, it consumed at least 72% of the exogenous mDON and notably reduced the amount of protein/amino sugar-like compounds. Irrespective of the influent, AB ultimately produced more various unsaturated hydrocarbon and lignin analogues. Redundancy and network analysis highlighted the algal-bacterial synergistic effects exemplified by cross-feeding in reducing mDON concentrations and shaping mDON pools. Moreover, metagenomics-based metabolic reconstruction revealed that cyanobacteria Limnothrix and Kamptonema spp. facilitated mDON uptake, ammonification, and recycling, which supplied the extensive nitrogen assimilatory demand for amino acids, vitamins, and cofactors biosynthesis, and therefore promoted mDON scavenging. Our findings demonstrate that regardless of the secondary or tertiary process, cyanobacteria-dominated AB is promising to minimize bioavailable mDON discharges, which has implications for future eutrophication control.
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Affiliation(s)
- Yuan Lin
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, No. 163 Xianlin Avenue, Nanjing 210023, Jiangsu, P. R. China
| | - Liye Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, No. 163 Xianlin Avenue, Nanjing 210023, Jiangsu, P. R. China
| | - Ke Xu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, No. 163 Xianlin Avenue, Nanjing 210023, Jiangsu, P. R. China
| | - Hui Huang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, No. 163 Xianlin Avenue, Nanjing 210023, Jiangsu, P. R. China
| | - Hongqiang Ren
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, No. 163 Xianlin Avenue, Nanjing 210023, Jiangsu, P. R. China
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Lui LM, Majumder ELW, Smith HJ, Carlson HK, von Netzer F, Fields MW, Stahl DA, Zhou J, Hazen TC, Baliga NS, Adams PD, Arkin AP. Mechanism Across Scales: A Holistic Modeling Framework Integrating Laboratory and Field Studies for Microbial Ecology. Front Microbiol 2021; 12:642422. [PMID: 33841364 PMCID: PMC8024649 DOI: 10.3389/fmicb.2021.642422] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 02/22/2021] [Indexed: 11/13/2022] Open
Abstract
Over the last century, leaps in technology for imaging, sampling, detection, high-throughput sequencing, and -omics analyses have revolutionized microbial ecology to enable rapid acquisition of extensive datasets for microbial communities across the ever-increasing temporal and spatial scales. The present challenge is capitalizing on our enhanced abilities of observation and integrating diverse data types from different scales, resolutions, and disciplines to reach a causal and mechanistic understanding of how microbial communities transform and respond to perturbations in the environment. This type of causal and mechanistic understanding will make predictions of microbial community behavior more robust and actionable in addressing microbially mediated global problems. To discern drivers of microbial community assembly and function, we recognize the need for a conceptual, quantitative framework that connects measurements of genomic potential, the environment, and ecological and physical forces to rates of microbial growth at specific locations. We describe the Framework for Integrated, Conceptual, and Systematic Microbial Ecology (FICSME), an experimental design framework for conducting process-focused microbial ecology studies that incorporates biological, chemical, and physical drivers of a microbial system into a conceptual model. Through iterative cycles that advance our understanding of the coupling across scales and processes, we can reliably predict how perturbations to microbial systems impact ecosystem-scale processes or vice versa. We describe an approach and potential applications for using the FICSME to elucidate the mechanisms of globally important ecological and physical processes, toward attaining the goal of predicting the structure and function of microbial communities in chemically complex natural environments.
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Affiliation(s)
- Lauren M. Lui
- Division of Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Erica L.-W. Majumder
- Department of Bacteriology, University of Wisconsin–Madison, Madison, WI, United States
| | - Heidi J. Smith
- Center for Biofilm Engineering, Department of Microbiology and Immunology, Montana State University, Bozeman, MT, United States
| | - Hans K. Carlson
- Division of Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Frederick von Netzer
- Department of Civil and Environmental Engineering, University of Washington, Seattle, WA, United States
| | - Matthew W. Fields
- Center for Biofilm Engineering, Department of Microbiology and Immunology, Montana State University, Bozeman, MT, United States
| | - David A. Stahl
- Department of Civil and Environmental Engineering, University of Washington, Seattle, WA, United States
| | - Jizhong Zhou
- Institute for Environmental Genomics, Department of Microbiology & Plant Biology, School of Civil Engineering and Environmental Sciences, University of Oklahoma, Norman, OK, United States
| | - Terry C. Hazen
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, Knoxville, TN, United States
| | | | - Paul D. Adams
- Division of Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
- Department of Bioengineering, University of California, Berkeley, Berkeley, CA, United States
| | - Adam P. Arkin
- Division of Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
- Department of Bioengineering, University of California, Berkeley, Berkeley, CA, United States
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Hellman M, Hubalek V, Juhanson J, Almstrand R, Peura S, Hallin S. Substrate type determines microbial activity and community composition in bioreactors for nitrate removal by denitrification at low temperature. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 755:143023. [PMID: 33158531 DOI: 10.1016/j.scitotenv.2020.143023] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 10/08/2020] [Accepted: 10/08/2020] [Indexed: 06/11/2023]
Abstract
High levels of nitrogen originating from blasting operations, for example at mining sites or quarries, risk contaminating water bodies through leaching from waste rock dumps. Woodchip bioreactors can be a simple and cost-effective way of reducing nitrate concentrations in the leachate. In this study we investigated how bottle sedge, barley straw, and pine woodchips used as electron donors for denitrification influenced microbial community composition and nitrate removal in lab-scale bioreactors during 270 days. The reactors were operated to ensure that nitrate was never limiting and to achieve similar nitrate removal (%). Distinct bacterial communities developed due to the different substrates, as determined by sequencing of the 16S rRNA gene. Sedge and straw reactors shared more taxa with each other than with woodchips and throughout the experimental period, sedge and straw were more diverse than woodchips. Cellulose degrading bacteria like Fibrobacteres and Verrucomicrobia were detected in the substrates after 100-150 days of operation. Nitrate removal rates were highest in the sedge and straw reactors. After initial fluctuations, these reactors removed 5.1-6.3 g N m-3 water day-1, which was 3.3-4.4 times more than in the woodchip reactors. This corresponded to 48%, 42%, and 44% nitrate removal for the sedge, straw, and woodchip reactors respectively. The functional communities were characterized by quantitative PCR and denitrification was the major nitrate removing process based on genetic potential and water chemistry, although sedge and straw developed a capacity for ammonification. Gene ratios suggested that denitrification was initially incomplete and terminating with nitrous oxide. An increase in abundances of nitrous oxide reducing capacity in all substrate types towards the end increased the potential for less emissions of the greenhouse gas nitrous oxide.
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Affiliation(s)
- Maria Hellman
- Swedish University of Agricultural Sciences, Department of Forest Mycology and Plant Pathology, Box 7026, 75007 Uppsala, Sweden.
| | - Valerie Hubalek
- Swedish University of Agricultural Sciences, Department of Forest Mycology and Plant Pathology, Box 7026, 75007 Uppsala, Sweden.
| | - Jaanis Juhanson
- Swedish University of Agricultural Sciences, Department of Forest Mycology and Plant Pathology, Box 7026, 75007 Uppsala, Sweden.
| | - Robert Almstrand
- Swedish University of Agricultural Sciences, Department of Forest Mycology and Plant Pathology, Box 7026, 75007 Uppsala, Sweden.
| | - Sari Peura
- Swedish University of Agricultural Sciences, Department of Forest Mycology and Plant Pathology, Box 7026, 75007 Uppsala, Sweden.
| | - Sara Hallin
- Swedish University of Agricultural Sciences, Department of Forest Mycology and Plant Pathology, Box 7026, 75007 Uppsala, Sweden.
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Abstract
Nitrate-reducing bacteria (NRB) and sulfate-reducing bacteria (SRB) colonize diverse anoxic environments, including soil subsurface, groundwater, and wastewater. NRB and SRB compete for resources, and their interplay has major implications on the global cycling of nitrogen and sulfur species, with undesirable outcomes in some contexts. Competition between nitrate-reducing bacteria (NRB) and sulfate-reducing bacteria (SRB) for resources in anoxic environments is generally thought to be governed largely by thermodynamics. It is now recognized that intermediates of nitrogen and sulfur cycling (e.g., hydrogen sulfide, nitrite, etc.) can also directly impact NRB and SRB activities in freshwater, wastewater, and sediment and therefore may play important roles in competitive interactions. Here, through comparative transcriptomic and metabolomic analyses, we have uncovered mechanisms of hydrogen sulfide- and cysteine-mediated inhibition of nitrate respiratory growth for the NRB Intrasporangium calvum C5. Specifically, the systems analysis predicted that cysteine and hydrogen sulfide inhibit growth of I. calvum C5 by disrupting distinct steps across multiple pathways, including branched-chain amino acid (BCAA) biosynthesis, utilization of specific carbon sources, and cofactor metabolism. We have validated these predictions by demonstrating that complementation with BCAAs and specific carbon sources relieves the growth inhibitory effects of cysteine and hydrogen sulfide. We discuss how these mechanistic insights give new context to the interplay and stratification of NRB and SRB in diverse environments. IMPORTANCE Nitrate-reducing bacteria (NRB) and sulfate-reducing bacteria (SRB) colonize diverse anoxic environments, including soil subsurface, groundwater, and wastewater. NRB and SRB compete for resources, and their interplay has major implications on the global cycling of nitrogen and sulfur species, with undesirable outcomes in some contexts. For instance, the removal of reactive nitrogen species by NRB is desirable for wastewater treatment, but in agricultural soils, NRB can drive the conversion of nitrates from fertilizers into nitrous oxide, a potent greenhouse gas. Similarly, the hydrogen sulfide produced by SRB can help sequester and immobilize toxic heavy metals but is undesirable in oil wells where competition between SRB and NRB has been exploited to suppress hydrogen sulfide production. By characterizing how reduced sulfur compounds inhibit growth and activity of NRB, we have gained systems-level and mechanistic insight into the interplay of these two important groups of organisms and drivers of their stratification in diverse environments.
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Application of natural biodegradable fiber as biofilm medium and carbon source in DEnitrifying AMmonium OXidation (DEAMOX) process for nitrogen removal from wastewater. J Taiwan Inst Chem Eng 2021. [DOI: 10.1016/j.jtice.2021.01.030] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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Rosier BT, Moya-Gonzalvez EM, Corell-Escuin P, Mira A. Isolation and Characterization of Nitrate-Reducing Bacteria as Potential Probiotics for Oral and Systemic Health. Front Microbiol 2020; 11:555465. [PMID: 33042063 PMCID: PMC7522554 DOI: 10.3389/fmicb.2020.555465] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 08/24/2020] [Indexed: 12/29/2022] Open
Abstract
Recent evidence indicates that the reduction of salivary nitrate by oral bacteria can contribute to prevent oral diseases, as well as increase systemic nitric oxide levels that can improve conditions such as hypertension and diabetes. The objective of the current manuscript was to isolate nitrate-reducing bacteria from the oral cavity of healthy donors and test their in vitro probiotic potential to increase the nitrate-reduction capacity (NRC) of oral communities. Sixty-two isolates were obtained from five different donors of which 53 were confirmed to be nitrate-reducers. Ten isolates were selected based on high NRC as well as high growth rates and low acidogenicity, all being Rothia species. The genomes of these ten isolates confirmed the presence of nitrate- and nitrite reductase genes, as well as lactate utilization genes, and the absence of antimicrobial resistance, mobile genetic elements and virulence genes. The pH at which most nitrate was reduced differed between strains. However, acidic pH 6 always stimulated the reduction of nitrite compared to neutral pH 7 or slightly alkaline pH 7.5 (p < 0.01). We tested the effect of six out of 10 isolates on in vitro oral biofilm development in the presence or absence of 6.5 mM nitrate. The integration of the isolates into in vitro communities was confirmed by Illumina sequencing. The NRC of the bacterial communities increased when adding the isolates compared to controls without isolates (p < 0.05). When adding nitrate (prebiotic treatment) or isolates in combination with nitrate (symbiotic treatment), a smaller decrease in pH derived from sugar metabolism was observed (p < 0.05), which for some symbiotic combinations appeared to be due to lactate consumption. Interestingly, there was a strong correlation between the NRC of oral communities and ammonia production even in the absence of nitrate (R = 0.814, p < 0.01), which indicates that bacteria involved in these processes are related. As observed in our study, individuals differ in their NRC. Thus, some may have direct benefits from nitrate as a prebiotic as their microbiota naturally reduces significant amounts, while others may benefit more from a symbiotic combination (nitrate + nitrate-reducing probiotic). Future clinical studies should test the effects of these treatments on oral and systemic health.
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Affiliation(s)
| | | | | | - Alex Mira
- Department of Health and Genomics, Center for Advanced Research in Public Health, FISABIO Foundation, Valencia, Spain
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