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Chen J, Hu G, Liu J, Poulain AJ, Pu Q, Huang R, Meng B, Feng X. The divergent effects of nitrate and ammonium application on mercury methylation, demethylation, and reduction in flooded paddy slurries. JOURNAL OF HAZARDOUS MATERIALS 2023; 460:132457. [PMID: 37669605 DOI: 10.1016/j.jhazmat.2023.132457] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 07/30/2023] [Accepted: 08/30/2023] [Indexed: 09/07/2023]
Abstract
The production of methylmercury (MeHg) in flooded paddy fields determines its accumulation in rice grains; this, in turn, results in MeHg exposure risks for not only rice-eating humans but also wildlife. Nitrogen (N) fertilizers have been widely applied in rice cultivation fields to supply essential nutrients. However, the effects of N fertilizer addition on mercury (Hg) transformations are not unclear. This limits our understanding of MeHg formation in rice paddy ecosystems. In this study, we spiked three Hg tracers (200HgII, Me198Hg, and 202Hg0) in paddy slurries fertilized with urea, ammonium, and nitrate. The influences of N fertilization on Hg methylation, demethylation, and reduction and the underlying mechanisms were elucidated. The results revealed that dissimilatory nitrate reduction was the dominant process in the incubated paddy slurries. Nitrate addition inhibited HgII reduction, HgII methylation, and MeHg demethylation. Competition between nitrates and other electron acceptors (e.g., HgII, sulfate, or carbon dioxide) under dark conditions was the mechanism underlying nitrate-regulated Hg transformation. Ammonium and urea additions promoted HgII reduction, and anaerobic ammonium oxidation coupled with HgII reduction (Hgammox) was likely the reason. This work highlighted that nitrate addition not only inhibited HgII methylation but also reduced the demethylation of MeHg and therefore may generate more accumulation of MeHg in the incubated paddy slurries. Findings from this study link the biogeochemical cycling of N and Hg and provide crucial knowledge for assessing Hg risks in intermittently flooded wetland ecosystems.
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Affiliation(s)
- Ji Chen
- College of Chemical Engineering, Huaqiao University, Xiamen 361021, China; State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Gongren Hu
- College of Chemical Engineering, Huaqiao University, Xiamen 361021, China
| | - Jiang Liu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Alexandre J Poulain
- Biology Department, University of Ottawa, 30 Marie Curie, Ottawa, ON K1N 6N5, Canada
| | - Qiang Pu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Rong Huang
- College of Resources, Sichuan Agricultural University, Chengdu 611130, China
| | - Bo Meng
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China.
| | - Xinbin Feng
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
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Wan R, Zha Y, Wu M, Li X, Yang H, Liu H. Long-term effective remediation of black-odorous water via regulating calcium nitrate sustained-release. ENVIRONMENTAL MONITORING AND ASSESSMENT 2023; 195:1065. [PMID: 37598137 DOI: 10.1007/s10661-023-11659-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 08/01/2023] [Indexed: 08/21/2023]
Abstract
Nitrate addition is reported as a cost-effective method for remediating black-odorous water, which is mainly induced by the deficiency of electron acceptor. However, excessive release of nitrate and lack of long-term effectiveness significantly limited the application of direct nitrate dosing technology. Herein, for remediating black-odorous water, we constructed a nitrate sustained-release ecological concrete (ecoN-concrete), in which calcium nitrate (Ca(NO3)2) was dosed into concrete block to regulate the release of nitrate. The results showed that chemical oxygen demand (COD), turbidity, ammonia, phosphate, and sulfate were significantly removed in an ecoN-concrete-contained reactor fed with black-odorous water, and its removal efficiency was largely dependent on Ca(NO3)2 dosage. Meanwhile, the released nitrate was lower than 25% of its total dosage and nitrite was lower than 1.5 mg/L during 14 days remediation. After three recycles, the removal efficiencies of COD and turbidity by using ecoN-concrete were still more than 85%, indicating an excellent nitrate sustained-release performance of ecoN-concrete, which can be applied for preventing water re-blackening and re-stinking. Further investigation illustrated that the ecoN-concrete (1) decreased the abundance of Desulfovibrio, Desulfomonile, and Desulforhabdus in the phylum of Desulfobacterota to alleviate the odorous gas production and (2) significantly increased the abundance of Bacillus and Thermomonas, which utilized the released-nitrate for consuming organic matters and ammonia. This study provided an artful Ca(NO3)2 dosing strategy and long-term effective method for black-odorous water remediation.
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Affiliation(s)
- Rui Wan
- School of Ecology and Environment, Anhui Normal University, Wuhu, 241002, China.
| | - Yunyi Zha
- School of Ecology and Environment, Anhui Normal University, Wuhu, 241002, China
| | - Mengqi Wu
- School of Ecology and Environment, Anhui Normal University, Wuhu, 241002, China
| | - Xiaoxiao Li
- School of Ecology and Environment, Anhui Normal University, Wuhu, 241002, China
- College of Environment, Hohai University, Nanjing, 210098, China
| | - Haifeng Yang
- Donghu Innovation Center, Anhui Phoneya Environmental Technology Co. Ltd, Hefei, 230601, China
| | - Hongming Liu
- College of Life Sciences, Anhui Normal University, Wuhu, 241001, China
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Chen Z, Huang Y, Shen Y, Zhang J, Deng J, Chen X. Denitrification shifted autotroph-heterotroph interactions in Microcystis aggregates. ENVIRONMENTAL RESEARCH 2023; 231:116269. [PMID: 37257745 DOI: 10.1016/j.envres.2023.116269] [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: 03/14/2023] [Revised: 05/13/2023] [Accepted: 05/27/2023] [Indexed: 06/02/2023]
Abstract
Denitrification is the most important process for nitrogen removal in eutrophic lakes and was mostly investigated in lake sediment. Denitrification could also be mediated by cyanobacterial aggregates, yet how this process impacts nitrogen (N) availability and the associated autotroph-heterotroph relationships within cyanobacterial aggregates has not been investigated. In this study, incubation experiments with nitrate amendment were conducted with Microcystis aggregates (MAs). Measurement of nitrogen contents, 16S rRNA-based microbial community profiling and metatranscriptomic sequencing were used to jointly assess nitrogen turnover dynamics, as well as changes in microbial composition and gene expression. Strong denitrification potential was revealed, and maximal N removal was achieved within two days, after which the communities entered a state of severe N limitation. Changes of active microbial communities were further promoted both with regard to taxonomic composition and transcriptive activities. Expression of transportation-related genes confirmed competition for N sources by Microcystis and phycospheric communities. Strong stress response to reactive oxygen species by Microcystis was revealed. Notably, interspecific relationships among Microcystis and phycospheric communities exhibited a shift toward antagonistic interactions, particularly evidenced by overall increased expression of genes related to cell lysis and utilization of cellular materials. Patterns of fatty acid and starch metabolism also suggested changes in carbon metabolism and cross-feeding patterns within MAs. Taken together, this study demonstrated substantial denitrification potential of MAs, which, importantly, further induced changes in both metabolic activities and autotroph-heterotroph interactions. These findings also highlight the key role of nutrient condition in shaping autotroph-heterotroph relationships.
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Affiliation(s)
- Zhijie Chen
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restorations, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, China
| | - Yingying Huang
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restorations, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, China; Technology Innovation Center for Land Spatial Eco-restoration in Metropolitan Area, Ministry of Natural Resources, Shanghai, China.
| | - Yingshi Shen
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restorations, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, China
| | - Junyi Zhang
- Jiangsu Wuxi Environmental Monitoring Center, Jiangsu, China
| | - Jie Deng
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restorations, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, China; Technology Innovation Center for Land Spatial Eco-restoration in Metropolitan Area, Ministry of Natural Resources, Shanghai, China.
| | - Xuechu Chen
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restorations, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, China; Technology Innovation Center for Land Spatial Eco-restoration in Metropolitan Area, Ministry of Natural Resources, Shanghai, China
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4
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Jroundi F, Povedano-Priego C, Pinel-Cabello M, Descostes M, Grizard P, Purevsan B, Merroun ML. Evidence of microbial activity in a uranium roll-front deposit: Unlocking their potential role as bioenhancers of the ore genesis. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 861:160636. [PMID: 36464038 DOI: 10.1016/j.scitotenv.2022.160636] [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: 09/23/2022] [Revised: 11/26/2022] [Accepted: 11/28/2022] [Indexed: 06/17/2023]
Abstract
Uranium (U) roll-front deposits constitute a valuable source for an economical extraction by in situ recovery (ISR) mining. Such technology may induce changes in the subsurface microbiota, raising questions about the way their activities could build a functional ecosystem in such extreme environments (i.e.: oligotrophy and high SO4 concentration and salinity). Additionally, more information is needed to dissipate the doubts about the microbial role in the genesis of such U orebodies. A U roll-front deposit hosted in an aquifer driven system (in Zoovch Ovoo, Mongolia), intended for mining by acid ISR, was previously explored and showed to be governed by a complex bacterial diversity, linked to the redox zonation and the geochemical conditions. Here for the first time, transcriptional activities of microorganisms living in such U ore deposits are determined and their metabolic capabilities allocated in the three redox-inherited compartments, naturally defined by the roll-front system. Several genes encoding for crucial metabolic pathways demonstrated a strong biological role controlling the subsurface cycling of many elements including nitrate, sulfate, metals and radionuclides (e.g.: uranium), through oxidation-reduction reactions. Interestingly, the discovered transcriptional behaviour gives important insights into the good microbial adaptation to the geochemical conditions and their active contribution to the stabilization of the U ore deposits. Overall, evidences on the importance of these microbial metabolic activities in the aquifer system are discussed that may clarify the doubts on the microbial role in the genesis of low-temperature U roll-front deposits, along the Zoovch Ovoo mine.
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Affiliation(s)
- Fadwa Jroundi
- Department of Microbiology, Faculty of Science, University of Granada, Avda. Fuentenueva s/n, 18071 Granada, Spain.
| | - Cristina Povedano-Priego
- Department of Microbiology, Faculty of Science, University of Granada, Avda. Fuentenueva s/n, 18071 Granada, Spain
| | - María Pinel-Cabello
- Department of Microbiology, Faculty of Science, University of Granada, Avda. Fuentenueva s/n, 18071 Granada, Spain
| | - Michael Descostes
- ORANO Mining, 125 Avenue de Paris, 92330 Châtillon, France; Centre de Géosciences, MINES ParisTech, PSL University, 35 rue St Honoré, 77300 Fontainebleau, France
| | - Pierre Grizard
- ORANO Mining, 125 Avenue de Paris, 92330 Châtillon, France
| | - Bayaarma Purevsan
- Badrakh Energy LLC, Jamyan Gun Avenue - 9, Sukhbaatar district, 1st khoroo, UB-14240, Mongolia
| | - Mohamed L Merroun
- Department of Microbiology, Faculty of Science, University of Granada, Avda. Fuentenueva s/n, 18071 Granada, Spain
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Guan X, He R, Zhang B, Gao C, Liu F. Seasonal variations of microbial community structure, assembly processes, and influencing factors in karst river. Front Microbiol 2023; 14:1133938. [PMID: 37032860 PMCID: PMC10075313 DOI: 10.3389/fmicb.2023.1133938] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 03/03/2023] [Indexed: 04/11/2023] Open
Abstract
The physicochemical properties and microbial communities have significant annual and seasonal changes in karst aquifers. To explore the changes of microbial community and their relationships with environmental factors, water samples were collected from a typical karst river. Microbial communities in winter (Jan-2017 and Jan-2019) were stable with high similarity in spite of the 2 years sampling interval, but the microbial communities in Aug-2017 was different from that in Aug-2018. In four sampling times, there were 275 shared genera, whose average relative abundance ranging from 89.04 to 96.27%. The winter and summer specific genera were mainly from the recharge of tributary site K6 and discharge of waste water treatment plant (K2 and K3), respectively. The deterministic processes had a more significant effect on the microbial community assembly in winter than that in summer, which was affected by environmental pressure from pollution. Furthermore, antibiotics and inorganic nitrogen pollution affected element cycles of nitrogen and sulfur indirectly through microbial ecological modules in karst river, and the denitrification and desulfurization processes were potentially inhibited. These findings contributed to understand the changes and its assembly mechanism of microbial community, as well as the feedback to environment in polluted karst river.
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Affiliation(s)
- Xiangyu Guan
- School of Ocean Sciences, China University of Geosciences, Beijing, China
| | - Ruoxue He
- School of Ocean Sciences, China University of Geosciences, Beijing, China
- Department of Discipline Construction and Technology Development, Chengdu Technological University, Chengdu, China
| | - Biao Zhang
- School of Ocean Sciences, China University of Geosciences, Beijing, China
| | - Chengjie Gao
- Beijing Municipal Research Institute of Eco-Environmental Protection, Beijing, China
| | - Fei Liu
- Key Laboratory of Groundwater Conservation of MWR, China University of Geosciences, Beijing, China
- *Correspondence: Fei Liu,
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Dhar V, Singh R. Biohydrogen production potential with sulfate and nitrate removal by heat-pretreated enriched sulfate-reducing microorganisms-based bioelectrochemical system. Arch Microbiol 2022; 205:7. [PMID: 36454386 DOI: 10.1007/s00203-022-03352-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 11/06/2022] [Accepted: 11/21/2022] [Indexed: 12/03/2022]
Abstract
In this study, heat-pretreated sulfate-reducing bacteria (SRBs) were evaluated for simultaneous sulfate and nitrate removal in a bioelectrochemical system (BES). The effect of the applied potential of 20 mV to SRBs was evaluated at a sulfate concentration of 3 g/L and/or nitrate concentration of 0.5 g/L supplemented before heat pretreatment for sulfate and nitrate removal. The highest H2 production of 2.24 ± 0.04 mM/L in heat-pretreated culture was observed in the presence of sulfate at an applied potential of 20 mV (BHE-S). Simultaneous reduction of sulfate and nitrate was significant in BESs supplemented with either sulfate or nitrate during heat-shock pretreatment of the culture. The highest SO42- removal of 88.91 ± 0.8% was found in culture heat pretreated with NO3- and applied with 20 mV potential (BHE-N). The kinetics of heat-pretreated culture showed higher R2 and ultimate potential for H2 on the continuous application of 20 mV potential.
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Affiliation(s)
- Varsha Dhar
- School of Environment and Sustainable Development, Central University of Gujarat, Gandhinagar, 382030, India
| | - Rajesh Singh
- School of Environment and Sustainable Development, Central University of Gujarat, Gandhinagar, 382030, India.
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7
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Ostermeyer P, Van Landuyt J, Bonin L, Folens K, Williamson A, Hennebel T, Rabaey K. High rate production of concentrated sulfides from metal bearing wastewater in an expanded bed hydrogenotrophic sulfate reducing bioreactor. ENVIRONMENTAL SCIENCE AND ECOTECHNOLOGY 2022; 11:100173. [PMID: 36158753 PMCID: PMC9488047 DOI: 10.1016/j.ese.2022.100173] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Revised: 03/28/2022] [Accepted: 03/29/2022] [Indexed: 06/16/2023]
Abstract
Metallurgical wastewaters contain high concentrations of sulfate, up to 15 g L-1. Sulfate-reducing bioreactors are employed to treat these wastewaters, reducing sulfates to sulfides which subsequently co-precipitate metals. Sulfate loading and reduction rates are typically restricted by the total H2S concentration. Sulfide stripping, sulfide precipitation and dilution are the main strategies employed to minimize inhibition by H2S, but can be adversely compromised by suboptimal sulfate reduction, clogging and additional energy costs. Here, metallurgical wastewater was treated for over 250 days using two hydrogenotrophic granular activated carbon expanded bed bioreactors without additional removal of sulfides. H2S toxicity was minimized by operating at pH 8 ± 0.15, resulting in an average sulfate removal of 7.08 ± 0.08 g L-1, sulfide concentrations of 2.1 ± 0.2 g L-1 and peaks up to 2.3 ± 0.2 g L-1. A sulfate reduction rate of 20.6 ± 0.9 g L-1 d-1 was achieved, with maxima up to 27.2 g L-1 d-1, which is among the highest reported considering a literature review of 39 studies. The rates reported here are 6-8 times higher than those reported for other reactors without active sulfide removal and the only reported for expanded bed sulfate-reducing bioreactors using H2. By increasing the influent sulfate concentration and maintaining high sulfide concentrations, sulfate reducers were promoted while fermenters and methanogens were suppressed. Industrial wastewater containing 4.4 g L-1 sulfate, 0.036 g L-1 nitrate and various metals (As, Fe, Tl, Zn, Ni, Sb, Co and Cd) was successfully treated with all metal(loid)s, nitrates and sulfates removed below discharge limits.
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Affiliation(s)
- Pieter Ostermeyer
- Center of Microbial Ecology and Technology (CMET), Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000, Gent, Belgium
- CAPTURE, Frieda Saeysstraat 1, 9000, Gent, Belgium1
www.capture-resources.be
| | - Josefien Van Landuyt
- Center of Microbial Ecology and Technology (CMET), Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000, Gent, Belgium
| | - Luiza Bonin
- Center of Microbial Ecology and Technology (CMET), Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000, Gent, Belgium
- CAPTURE, Frieda Saeysstraat 1, 9000, Gent, Belgium1
www.capture-resources.be
| | - Karel Folens
- Center of Microbial Ecology and Technology (CMET), Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000, Gent, Belgium
| | - Adam Williamson
- Center of Microbial Ecology and Technology (CMET), Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000, Gent, Belgium
- CENBG, Université de Bordeaux, CNRS-IN2P3/, 19 chemin du Solarium, CS10120, 33175, Gradignan, France
| | - Tom Hennebel
- Center of Microbial Ecology and Technology (CMET), Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000, Gent, Belgium
- CAPTURE, Frieda Saeysstraat 1, 9000, Gent, Belgium1
www.capture-resources.be - Umicore, Group Research & Development, Competence Area Recycling and Extraction Technologies, Watertorenstraat 33, B-2250, Olen, Belgium
| | - Korneel Rabaey
- Center of Microbial Ecology and Technology (CMET), Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000, Gent, Belgium
- CAPTURE, Frieda Saeysstraat 1, 9000, Gent, Belgium1
www.capture-resources.be
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Zhou J, Xing J. Haloalkaliphilic denitrifiers-dependent sulfate-reducing bacteria thrive in nitrate-enriched environments. WATER RESEARCH 2021; 201:117354. [PMID: 34157573 DOI: 10.1016/j.watres.2021.117354] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 05/17/2021] [Accepted: 06/06/2021] [Indexed: 06/13/2023]
Abstract
As bridge in global cycles of carbon, nitrogen, and sulfur, sulfate-reducing bacteria (SRB) play more and more important role under various environments, especially the saline-alkali environments with significant increase in area caused by human activities. Sulfate reduction can be inhibited by environmental nitrate. However, how SRB cope with environmental nitrate stress in these extreme environments still remain unclear. Here, after a long-term enrichment of sediment from saline-alkali Qinghai Lake of China using anaerobic filter reactors, nitrate was added to evaluate the response of SRB. With the increase in nitrate concentrations, the inhibition on sulfate reduction was gradually observed. Interestingly, extension of hydraulic retention time can relieve the inhibition caused by high nitrate concentration. Mass balance analysis showed that nitrate reduction is prior to sulfate reduction. Further metatranscriptomic analysis shows that, genes of nitrite reductase (periplasmic cytochrome c nitrite reductase gene) and energy metabolisms (lactate dehydrogenase, formate dehydrogenase, pyruvate:ferredoxin-oxidoreductase, and fumarate reductase genes) in SRB was down-regulated, challenging the long-held opinion that up-regulation of these genes can relieve the nitrate inhibition. Most importantly, the nitrate addition activated the denitrification pathway in denitrifying bacteria (DB) via significantly up-regulating the expression of the corresponding genes (nitrite reductase, nitric oxide reductase c subunit, nitric oxide reductase activation protein and nitrous oxide reductase genes), quickly reducing the environmental nitrate and relieving the nitrate inhibition on SRB. Our findings unravel that in response to environmental nitrate stress, haloalkaliphilic SRB show dependency on DB, and expand our knowledge of microbial relationship during sulfur and nitrogen cycles.
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Affiliation(s)
- Jiemin Zhou
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| | - Jianmin Xing
- Key Laboratory of Green Process and Engineering, State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
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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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Experimental evolution reveals nitrate tolerance mechanisms in Desulfovibrio vulgaris. ISME JOURNAL 2020; 14:2862-2876. [PMID: 32934357 DOI: 10.1038/s41396-020-00753-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 08/09/2020] [Accepted: 08/17/2020] [Indexed: 11/08/2022]
Abstract
Elevated nitrate in the environment inhibits sulfate reduction by important microorganisms of sulfate-reducing bacteria (SRB). Several SRB may respire nitrate to survive under elevated nitrate, but how SRB that lack nitrate reductase survive to elevated nitrate remains elusive. To understand nitrate adaptation mechanisms, we evolved 12 populations of a model SRB (i.e., Desulfovibrio vulgaris Hildenborough, DvH) under elevated NaNO3 for 1000 generations, analyzed growth and acquired mutations, and linked their genotypes with phenotypes. Nitrate-evolved (EN) populations significantly (p < 0.05) increased nitrate tolerance, and whole-genome resequencing identified 119 new mutations in 44 genes of 12 EN populations, among which six functional gene groups were discovered with high mutation frequencies at the population level. We observed a high frequency of nonsense or frameshift mutations in nitrosative stress response genes (NSR: DVU2543, DVU2547, and DVU2548), nitrogen regulatory protein C family genes (NRC: DVU2394-2396, DVU2402, and DVU2405), and nitrate cluster (DVU0246-0249 and DVU0251). Mutagenesis analysis confirmed that loss-of-functions of NRC and NSR increased nitrate tolerance. Also, functional gene groups involved in fatty acid synthesis, iron regulation, and two-component system (LytR/LytS) known to be responsive to multiple stresses, had a high frequency of missense mutations. Mutations in those gene groups could increase nitrate tolerance through regulating energy metabolism, barring entry of nitrate into cells, altering cell membrane characteristics, or conferring growth advantages at the stationary phase. This study advances our understanding of nitrate tolerance mechanisms and has important implications for linking genotypes with phenotypes in DvH.
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Anion transport as a target of adaption to perchlorate in sulfate-reducing communities. ISME JOURNAL 2019; 14:450-462. [PMID: 31659234 DOI: 10.1038/s41396-019-0540-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 09/04/2019] [Accepted: 09/12/2019] [Indexed: 11/09/2022]
Abstract
Inhibitors can be used to control the functionality of microbial communities by targeting specific metabolisms. The targeted inhibition of dissimilatory sulfate reduction limits the generation of toxic and corrosive hydrogen sulfide across several industrial systems. Sulfate-reducing microorganisms (SRM) are specifically inhibited by sulfate analogs, such as perchlorate. Previously, we showed pure culture SRM adaptation to perchlorate stress through mutation of the sulfate adenylyltransferase, a central enzyme in the sulfate reduction pathway. Here, we explored adaptation to perchlorate across unconstrained SRM on a community scale. We followed natural and bio-augmented sulfidogenic communities through serial transfers in increasing concentrations of perchlorate. Our results demonstrated that perchlorate stress altered community structure by initially selecting for innately more resistant strains. Isolation, whole-genome sequencing, and molecular biology techniques allowed us to define subsequent genetic mechanisms of adaptation that arose across the dominant adapting SRM. Changes in the regulation of divalent anion:sodium symporter family transporters led to increased intracellular sulfate to perchlorate ratios, allowing SRM to escape the effects of competitive inhibition. Thus, in contrast to pure-culture results, SRM in communities cope with perchlorate stress via changes in anion transport and its regulation. This highlights the value of probing evolutionary questions in an ecological framework, bridging the gap between ecology, evolution, genomics, and physiology.
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12
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Shen J, Zerkle AL, Stueeken E, Claire MW. Nitrates as a Potential N Supply for Microbial Ecosystems in a Hyperarid Mars Analog System. Life (Basel) 2019; 9:life9040079. [PMID: 31635024 PMCID: PMC6958444 DOI: 10.3390/life9040079] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 10/08/2019] [Accepted: 10/17/2019] [Indexed: 11/16/2022] Open
Abstract
Nitrate is common in Mars sediments owing to long-term atmospheric photolysis, oxidation, and potentially, impact shock heating. The Atacama Desert in Chile, which is the driest region on Earth and rich in nitrate deposits, is used as a Mars analog in this study to explore the potential effects of high nitrate levels on growth of extremophilic ecosystems. Seven study sites sampled across an aridity gradient in the Atacama Desert were categorized into 3 clusters—hyperarid, middle, and arid sites—as defined by essential soil physical and chemical properties. Intriguingly, the distribution of nitrate concentrations in the shallow subsurface suggests that the buildup of nitrate is not solely controlled by precipitation. Correlations of nitrate with SiO2/Al2O3 and grain sizes suggest that sedimentation rates may also be important in controlling nitrate distribution. At arid sites receiving more than 10 mm/yr precipitation, rainfall shows a stronger impact on biomass than nitrate does. However, high nitrate to organic carbon ratios are generally beneficial to N assimilation, as evidenced both by soil geochemistry and enriched culturing experiments. This study suggests that even in the absence of precipitation, nitrate levels on a more recent, hyperarid Mars could be sufficiently high to benefit potentially extant Martian microorganisms.
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Affiliation(s)
- Jianxun Shen
- School of Earth and Environmental Sciences and Centre for Exoplanet Science, University of St Andrews, St Andrews KY16 9AL, Scotland, UK.
| | - Aubrey L Zerkle
- School of Earth and Environmental Sciences and Centre for Exoplanet Science, University of St Andrews, St Andrews KY16 9AL, Scotland, UK.
| | - Eva Stueeken
- School of Earth and Environmental Sciences and Centre for Exoplanet Science, University of St Andrews, St Andrews KY16 9AL, Scotland, UK.
| | - Mark W Claire
- School of Earth and Environmental Sciences and Centre for Exoplanet Science, University of St Andrews, St Andrews KY16 9AL, Scotland, UK.
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13
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Qian Z, Tianwei H, Mackey HR, van Loosdrecht MCM, Guanghao C. Recent advances in dissimilatory sulfate reduction: From metabolic study to application. WATER RESEARCH 2019; 150:162-181. [PMID: 30508713 DOI: 10.1016/j.watres.2018.11.018] [Citation(s) in RCA: 82] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 10/25/2018] [Accepted: 11/08/2018] [Indexed: 05/24/2023]
Abstract
Sulfate-reducing bacteria (SRB) are a group of diverse anaerobic microorganisms omnipresent in natural habitats and engineered environments that use sulfur compounds as the electron acceptor for energy metabolism. Dissimilatory sulfate reduction (DSR)-based techniques mediated by SRB have been utilized in many sulfate-containing wastewater treatment systems worldwide, particularly for acid mine drainage, groundwater, sewage and industrial wastewater remediation. However, DSR processes are often operated suboptimally and disturbances are common in practical application. To improve the efficiency and robustness of SRB-based processes, it is necessary to study SRB metabolism and operational conditions. In this review, the mechanisms of DSR processes are reviewed and discussed focusing on intracellular and extracellular electron transfer with different electron donors (hydrogen, organics, methane and electrodes). Based on the understanding of the metabolism of SRB, responses of SRB to environmental stress (pH-, temperature-, and salinity-related stress) are summarized at the species and community levels. Application in these stressed conditions is discussed and future research is proposed. The feasibility of recovering energy and resources such as biohydrogen, hydrocarbons, polyhydroxyalkanoates, magnetite and metal sulfides through the use of SRB were investigated but some long-standing questions remain unanswered. Linking the existing scientific understanding and observations to practical application is the challenge as always for promotion of SRB-based techniques.
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Affiliation(s)
- Zeng Qian
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Hao Tianwei
- Department of Civil and Environmental Engineering, Faculty of Science and Technology, University of Macau, Macau, China; Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China.
| | - Hamish Robert Mackey
- Division of Sustainable Development, College of Science and Engineering, Hamad Bin Khalifa University, Qatar Foundation, Doha, Qatar
| | | | - Chen Guanghao
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China; Water Technology Center, The Hong Kong University of Science and Technology, Hong Kong, China; Hong Kong Branch of Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science and Technology, Hong Kong, China; Wastewater Treatment Laboratory, FYT Graduate School, The Hong Kong University of Science and Technology, Nansha, Guangzhou, China.
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14
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Stoeva MK, Coates JD. Specific inhibitors of respiratory sulfate reduction: towards a mechanistic understanding. MICROBIOLOGY-SGM 2018; 165:254-269. [PMID: 30556806 DOI: 10.1099/mic.0.000750] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Microbial sulfate reduction (SR) by sulfate-reducing micro-organisms (SRM) is a primary environmental mechanism of anaerobic organic matter mineralization, and as such influences carbon and sulfur cycling in many natural and engineered environments. In industrial systems, SR results in the generation of hydrogen sulfide, a toxic, corrosive gas with adverse human health effects and significant economic and environmental consequences. Therefore, there has been considerable interest in developing strategies for mitigating hydrogen sulfide production, and several specific inhibitors of SRM have been identified and characterized. Specific inhibitors are compounds that disrupt the metabolism of one group of organisms, with little or no effect on the rest of the community. Putative specific inhibitors of SRM have been used to control sulfidogenesis in industrial and engineered systems. Despite the value of these inhibitors, mechanistic and quantitative studies into the molecular mechanisms of their inhibition have been sparse and unsystematic. The insight garnered by such studies is essential if we are to have a more complete understanding of SR, including the past and current selective pressures acting upon it. Furthermore, the ability to reliably control sulfidogenesis - and potentially assimilatory sulfate pathways - relies on a thorough molecular understanding of inhibition. The scope of this review is to summarize the current state of the field: how we measure and understand inhibition, the targets of specific SR inhibitors and how SRM acclimatize and/or adapt to these stressors.
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Affiliation(s)
- Magdalena K Stoeva
- 1Energy Biosciences Institute, University of California - Berkeley, Berkeley, CA, USA
- 2Department of Plant and Microbial Biology, University of California - Berkeley, Berkeley, CA, USA
| | - John D Coates
- 2Department of Plant and Microbial Biology, University of California - Berkeley, Berkeley, CA, USA
- 1Energy Biosciences Institute, University of California - Berkeley, Berkeley, CA, USA
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15
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Chakraborty S, Kenney LJ. A New Role of OmpR in Acid and Osmotic Stress in Salmonella and E. coli. Front Microbiol 2018; 9:2656. [PMID: 30524381 PMCID: PMC6262077 DOI: 10.3389/fmicb.2018.02656] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 10/17/2018] [Indexed: 12/24/2022] Open
Abstract
Bacteria survive and respond to diverse environmental conditions and during infection inside the host by systematic regulation of stress response genes. E. coli and S. Typhimurium can undergo large changes in intracellular osmolality (up to 1.8 Osmol/kg) and can tolerate cytoplasmic acidification to at least pHi 5.6. Recent analyses of single cells challenged a long held view that bacteria respond to extracellular acid stress by rapid acidification followed by a rapid recovery. It is now appreciated that both S. Typhimurium and E. coli maintain an acidic cytoplasm through the actions of the outer membrane protein regulator OmpR via its regulation of distinct signaling pathways. However, a comprehensive comparison of OmpR regulons between S. Typhimurium and E. coli is lacking. In this study, we examined the expression profiles of wild-type and ompR null strains of the intracellular pathogen S. Typhimurium and a commensal E. coli in response to acid and osmotic stress. Herein, we classify distinct OmpR regulons and also identify shared OmpR regulatory pathways between S. Typhimurium and E. coli in response to acid and osmotic stress. Our study establishes OmpR as a key regulator of bacterial virulence, growth and metabolism, in addition to its role in regulating outer membrane proteins.
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Affiliation(s)
- Smarajit Chakraborty
- Mechanobiology Institute, National University of Singapore, Singapore, Singapore
| | - Linda J. Kenney
- Mechanobiology Institute, National University of Singapore, Singapore, Singapore
- Department of Biochemistry, National University of Singapore, Singapore, Singapore
- Departments of Microbiology and Immunology, University of Illinois at Chicago, Chicago, IL, United States
- Bioengineering, University of Illinois at Chicago, Chicago, IL, United States
- Jesse Brown Veterans Administration Medical Center, Chicago, IL, United States
- *Correspondence: Linda J. Kenney,
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16
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Barbosa AD, da Silva LF, de Paula HM, Romualdo LL, Sadoyama G, Andrade LS. Combined use of coagulation (M. oleifera) and electrochemical techniques in the treatment of industrial paint wastewater for reuse and/or disposal. WATER RESEARCH 2018; 145:153-161. [PMID: 30142513 DOI: 10.1016/j.watres.2018.08.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 07/30/2018] [Accepted: 08/09/2018] [Indexed: 06/08/2023]
Abstract
In this work, water-based paint (WBP) wastewater was treated using a natural coagulant, Moringa oleifera aqueous extract (MOAE), fortified with Ca2+ (from nitrate and chloride salts). In order to improve the quality of the treated wastewater and render it suitable for disposal, an electrolytic flow process was associated with the wastewater treatment using a filter-press reactor with a boron doped diamond (BDD) electrode. The feasibility of the treatment was evidenced by the reuse of the treated wastewater in the production of a new paint (manufactured by the company supplying the raw wastewater), whose quality was compatible with the water used by the manufacturer. The best conditions for the coagulation-flocculation process involved the use of 80 mL of MOAE (50 g/L of MO and 0.125 mol/L of Ca2+) for every 1.0 L of wastewater at pH 6.5. The limiting current density (35 mA/cm2) and an electrolysis time of 90 min (charge passed of 3.68 A h/L) were used in the electrochemical treatment. Biotoxicity assays using the brine shrimp Artemia salina revealed that the mortality (in %) of microcrustaceans was reduced from 100% (raw wastewater) to only 11% at the end of the electrolysis process, in addition to eliminating the strong odor and 85% of the organic load. Moreover, microbiological tests showed that the number of mesophiles decreased by more than six orders of magnitude and there was no growth of thermotolerant coliforms (TC).
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Affiliation(s)
- Andreia D Barbosa
- UAE-Chemistry, Federal University of Goiás (Universidade Federal de Goiás) - Regional Catalão, 75704-020 Catalão, GO, Brazil
| | - Larissa F da Silva
- UAE-Chemistry, Federal University of Goiás (Universidade Federal de Goiás) - Regional Catalão, 75704-020 Catalão, GO, Brazil
| | - Heber M de Paula
- Faculty of Engineering, Federal University of Goiás (Universidade Federal de Goiás) - Regional Catalão, 75704-020 Catalão, GO, Brazil
| | - Lincoln L Romualdo
- UAE-Chemistry, Federal University of Goiás (Universidade Federal de Goiás) - Regional Catalão, 75704-020 Catalão, GO, Brazil
| | - Geraldo Sadoyama
- IBIOTEC, Federal University of Goiás (Universidade Federal de Goiás) - Regional Catalão, 75704-020 Catalão, GO, Brazil
| | - Leonardo S Andrade
- UAE-Chemistry, Federal University of Goiás (Universidade Federal de Goiás) - Regional Catalão, 75704-020 Catalão, GO, Brazil.
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17
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Shatsky M, Allen S, Gold BL, Liu NL, Juba TR, Reveco SA, Elias DA, Prathapam R, He J, Yang W, Szakal ED, Liu H, Singer ME, Geller JT, Lam BR, Saini A, Trotter VV, Hall SC, Fisher SJ, Brenner SE, Chhabra SR, Hazen TC, Wall JD, Witkowska HE, Biggin MD, Chandonia JM, Butland G. Bacterial Interactomes: Interacting Protein Partners Share Similar Function and Are Validated in Independent Assays More Frequently Than Previously Reported. Mol Cell Proteomics 2016; 15:1539-55. [PMID: 26873250 DOI: 10.1074/mcp.m115.054692] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Indexed: 01/31/2023] Open
Abstract
Numerous affinity purification-mass spectrometry (AP-MS) and yeast two-hybrid screens have each defined thousands of pairwise protein-protein interactions (PPIs), most of which are between functionally unrelated proteins. The accuracy of these networks, however, is under debate. Here, we present an AP-MS survey of the bacterium Desulfovibrio vulgaris together with a critical reanalysis of nine published bacterial yeast two-hybrid and AP-MS screens. We have identified 459 high confidence PPIs from D. vulgaris and 391 from Escherichia coli Compared with the nine published interactomes, our two networks are smaller, are much less highly connected, and have significantly lower false discovery rates. In addition, our interactomes are much more enriched in protein pairs that are encoded in the same operon, have similar functions, and are reproducibly detected in other physical interaction assays than the pairs reported in prior studies. Our work establishes more stringent benchmarks for the properties of protein interactomes and suggests that bona fide PPIs much more frequently involve protein partners that are annotated with similar functions or that can be validated in independent assays than earlier studies suggested.
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Affiliation(s)
- Maxim Shatsky
- From the Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, 94720
| | - Simon Allen
- the Department of Obstetrics, Gynecology and Reproductive Sciences and Sandler-Moore Mass Spectrometry Core Facility, University of California at San Francisco, San Francisco, California, 94143
| | - Barbara L Gold
- the Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, 94720
| | - Nancy L Liu
- the Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, 94720
| | - Thomas R Juba
- the Departments of Biochemistry and of Molecular Microbiology and Immunology, University of Missouri, Columbia, Missouri, 65211
| | - Sonia A Reveco
- From the Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, 94720
| | - Dwayne A Elias
- the Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831
| | - Ramadevi Prathapam
- the Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, 94720
| | - Jennifer He
- the Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, 94720
| | - Wenhong Yang
- the Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, 94720
| | - Evelin D Szakal
- the Department of Obstetrics, Gynecology and Reproductive Sciences and Sandler-Moore Mass Spectrometry Core Facility, University of California at San Francisco, San Francisco, California, 94143
| | - Haichuan Liu
- the Department of Obstetrics, Gynecology and Reproductive Sciences and Sandler-Moore Mass Spectrometry Core Facility, University of California at San Francisco, San Francisco, California, 94143
| | - Mary E Singer
- the Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, 94720
| | - Jil T Geller
- the Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, 94720
| | - Bonita R Lam
- the Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, 94720
| | - Avneesh Saini
- the Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, 94720
| | - Valentine V Trotter
- the Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, 94720
| | - Steven C Hall
- the Department of Obstetrics, Gynecology and Reproductive Sciences and Sandler-Moore Mass Spectrometry Core Facility, University of California at San Francisco, San Francisco, California, 94143
| | - Susan J Fisher
- the Department of Obstetrics, Gynecology and Reproductive Sciences and Sandler-Moore Mass Spectrometry Core Facility, University of California at San Francisco, San Francisco, California, 94143
| | - Steven E Brenner
- From the Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, 94720; the Department of Plant and Microbial Biology, University of California at Berkeley, Berkeley, California, 94720
| | - Swapnil R Chhabra
- From the Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, 94720
| | - Terry C Hazen
- the Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, Tennessee, 37996; and
| | - Judy D Wall
- the Departments of Biochemistry and of Molecular Microbiology and Immunology, University of Missouri, Columbia, Missouri, 65211
| | - H Ewa Witkowska
- the Department of Obstetrics, Gynecology and Reproductive Sciences and Sandler-Moore Mass Spectrometry Core Facility, University of California at San Francisco, San Francisco, California, 94143
| | - Mark D Biggin
- the Genomics Division, Lawrence Berkeley National Laboratory, Berkeley, California, 94720
| | - John-Marc Chandonia
- From the Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, 94720;
| | - Gareth Butland
- the Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, 94720; From the Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, 94720;
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18
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Suitability of different growth substrates as source of nitrogen for sulfate reducing bacteria. Biodegradation 2015; 26:415-30. [DOI: 10.1007/s10532-015-9745-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 09/05/2015] [Indexed: 11/26/2022]
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Regulation of Nitrite Stress Response in Desulfovibrio vulgaris Hildenborough, a Model Sulfate-Reducing Bacterium. J Bacteriol 2015; 197:3400-8. [PMID: 26283774 DOI: 10.1128/jb.00319-15] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Accepted: 08/12/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Sulfate-reducing bacteria (SRB) are sensitive to low concentrations of nitrite, and nitrite has been used to control SRB-related biofouling in oil fields. Desulfovibrio vulgaris Hildenborough, a model SRB, carries a cytochrome c-type nitrite reductase (nrfHA) that confers resistance to low concentrations of nitrite. The regulation of this nitrite reductase has not been directly examined to date. In this study, we show that DVU0621 (NrfR), a sigma54-dependent two-component system response regulator, is the positive regulator for this operon. NrfR activates the expression of the nrfHA operon in response to nitrite stress. We also show that nrfR is needed for fitness at low cell densities in the presence of nitrite because inactivation of nrfR affects the rate of nitrite reduction. We also predict and validate the binding sites for NrfR upstream of the nrfHA operon using purified NrfR in gel shift assays. We discuss possible roles for NrfR in regulating nitrate reductase genes in nitrate-utilizing Desulfovibrio spp. IMPORTANCE The NrfA nitrite reductase is prevalent across several bacterial phyla and required for dissimilatory nitrite reduction. However, regulation of the nrfA gene has been studied in only a few nitrate-utilizing bacteria. Here, we show that in D. vulgaris, a bacterium that does not respire nitrate, the expression of nrfHA is induced by NrfR upon nitrite stress. This is the first report of regulation of nrfA by a sigma54-dependent two-component system. Our study increases our knowledge of nitrite stress responses and possibly of the regulation of nitrate reduction in SRB.
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da Silva SM, Amaral C, Neves SS, Santos C, Pimentel C, Rodrigues-Pousada C. An HcpR paralog of Desulfovibrio gigas provides protection against nitrosative stress. FEBS Open Bio 2015; 5:594-604. [PMID: 26273559 PMCID: PMC4534486 DOI: 10.1016/j.fob.2015.07.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Accepted: 07/01/2015] [Indexed: 01/12/2023] Open
Abstract
Desulfovibrio gigas genome encodes two HcpR paralogs, HcpR1 and HcpR2. Cells lacking HcpR1 are less tolerant to NO. HcpR1 regulates the expression of several genes related to nitrogen metabolism. Phylogenetic analyses indicate that the presence of HcpR paralogs is a common finding among Desulfovibrio species.
Desulfovibrio gigas belongs to the group of sulfate reducing bacteria (SRB). These ubiquitous and metabolically versatile microorganisms are often exposed to reactive nitrogen species (RNS). Nonetheless, the mechanisms and regulatory elements involved in nitrosative stress protection are still poorly understood. The transcription factor HcpR has emerged as a putative regulator of nitrosative stress response among anaerobic bacteria. HcpR is known to orchestrate the expression of the hybrid cluster protein gene, hcp, proposed to be involved in cellular defense against RNS. According to phylogenetic analyses, the occurrence of hcpR paralog genes is a common feature among several Desulfovibrio species. Within the D. gigas genome we have identified two HcpR-related sequences. One of these sequences, hcpR1, was found in the close vicinity of the hcp gene and this finding prompted us to proceed with its functional characterization. We observed that the growth of a D. gigas strain lacking hcpR1 is severely impaired under nitrosative stress. An in silico search revealed several putative targets of HcpR1 that were experimentally validated. The fact that HcpR1 regulates several genes encoding proteins involved in nitrite and nitrate metabolism, together with the sensitive growth phenotype to NO displayed by an hcpR1 mutant strain, strongly supports a relevant role of this factor under nitrosative stress. Moreover, the finding that several Desulfovibrio species possess HcpR paralogs, which have been transmitted vertically in the evolution and diversification of the genus, suggests that these sequences may confer adaptive or survival advantage to these organisms, possibly by increasing their tolerance to nitrosative stress.
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Key Words
- BI, Bayesian inference
- BS, bootstrap
- CRP/FNR, cAMP receptor protein/fumarate and nitrate reductase regulatory protein
- Desulfovibrio
- Frdx, ferredoxin
- GSNO, S-nitrosoglutathione
- HGT, horizontal gene transfer
- Hcp, hybrid cluster protein
- HcpR
- ML, maximum likelihood
- MP, maximum parsimony
- Molecular phylogeny
- NO, nitric oxide
- Nitrosative stress
- PP, posterior probability
- RNS, reactive nitrogen species
- ROO, rubredoxin oxygen reductase
- SRB, sulfate reducing bacteria
- Sulfate reducing bacteria
- Transcription regulation
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Affiliation(s)
- Sofia M da Silva
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal
| | - Catarina Amaral
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal
| | - Susana S Neves
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal
| | - Cátia Santos
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal
| | - Catarina Pimentel
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal
| | - Claudina Rodrigues-Pousada
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal
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A Post-Genomic View of the Ecophysiology, Catabolism and Biotechnological Relevance of Sulphate-Reducing Prokaryotes. Adv Microb Physiol 2015. [PMID: 26210106 DOI: 10.1016/bs.ampbs.2015.05.002] [Citation(s) in RCA: 174] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Dissimilatory sulphate reduction is the unifying and defining trait of sulphate-reducing prokaryotes (SRP). In their predominant habitats, sulphate-rich marine sediments, SRP have long been recognized to be major players in the carbon and sulphur cycles. Other, more recently appreciated, ecophysiological roles include activity in the deep biosphere, symbiotic relations, syntrophic associations, human microbiome/health and long-distance electron transfer. SRP include a high diversity of organisms, with large nutritional versatility and broad metabolic capacities, including anaerobic degradation of aromatic compounds and hydrocarbons. Elucidation of novel catabolic capacities as well as progress in the understanding of metabolic and regulatory networks, energy metabolism, evolutionary processes and adaptation to changing environmental conditions has greatly benefited from genomics, functional OMICS approaches and advances in genetic accessibility and biochemical studies. Important biotechnological roles of SRP range from (i) wastewater and off gas treatment, (ii) bioremediation of metals and hydrocarbons and (iii) bioelectrochemistry, to undesired impacts such as (iv) souring in oil reservoirs and other environments, and (v) corrosion of iron and concrete. Here we review recent advances in our understanding of SRPs focusing mainly on works published after 2000. The wealth of publications in this period, covering many diverse areas, is a testimony to the large environmental, biogeochemical and technological relevance of these organisms and how much the field has progressed in these years, although many important questions and applications remain to be explored.
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22
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Bundhoo MAZ, Mohee R, Hassan MA. Effects of pre-treatment technologies on dark fermentative biohydrogen production: A review. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2015; 157:20-48. [PMID: 25881150 DOI: 10.1016/j.jenvman.2015.04.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Revised: 04/05/2015] [Accepted: 04/07/2015] [Indexed: 05/24/2023]
Abstract
Biohydrogen production from dark fermentation of lignocellulosic materials represents a huge potential in terms of renewable energy exploitation. However, the low hydrogen yield is currently hindering its development on industrial scale. This study reviewed various technologies that have been investigated for enhancing dark fermentative biohydrogen production. The pre-treatment technologies can be classified based on their applications as inoculum or substrates pre-treatment or they can be categorised into physical, chemical, physicochemical and biological based on the techniques used. From the different technologies reviewed, heat and acid pre-treatments are the most commonly studied technologies for both substrates and inoculum pre-treatment. Nevertheless, these two technologies need not necessarily be the most suitable since across different studies, a wide array of other emerging techniques as well as combined technologies have yielded positive findings. To date, there exists no perfect technology for either inoculum or substrate pre-treatment. Although the aim of inoculum pre-treatment is to suppress H2-consumers and enrich H2-producers, many sporulating H2-consumers survive the pre-treatment while some non-spore H2-producers are inhibited. Besides, several inoculum pre-treatment techniques are not effective in the long run and repeated pre-treatment may be required for continuous suppression of H2-consumers and sustained biohydrogen production. Furthermore, many technologies employed for substrates pre-treatment may yield inhibitory compounds that can eventually decrease biohydrogen production. Consequently, much research needs to be done to find out the best technology for both substrates and inoculum pre-treatment while also taking into consideration the energetic, economic and technical feasibility of implementing such a process on an industrial scale.
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Affiliation(s)
- M A Zumar Bundhoo
- Department of Chemical & Environmental Engineering, Faculty of Engineering, University of Mauritius, Réduit, Mauritius.
| | | | - M Ali Hassan
- Department of Bioprocess Technology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor Darul Ehsan, Malaysia.
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23
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Korte HL, Saini A, Trotter VV, Butland GP, Arkin AP, Wall JD. Independence of nitrate and nitrite inhibition of Desulfovibrio vulgaris Hildenborough and use of nitrite as a substrate for growth. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:924-931. [PMID: 25534748 DOI: 10.1021/es504484m] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Sulfate-reducing microbes, such as Desulfovibrio vulgaris Hildenborough, cause “souring” of petroleum reservoirs through produced sulfide and precipitate heavy metals, either as sulfides or by alteration of the metal reduction state. Thus, inhibitors of these microbes, including nitrate and nitrite ions, are studied in order to limit their impact. Nitrite is a potent inhibitor of sulfate reducers, and it has been suggested that nitrate does not inhibit these microbes directly but by reduction to nitrite, which serves as the ultimate inhibitor. Here we provide evidence that nitrate inhibition of D. vulgaris can be independent of nitrite production. We also show that D. vulgaris can use nitrite as a nitrogen source or terminal electron acceptor for growth. Moreover, we report that use of nitrite as a terminal electron acceptor requires nitrite reductase (nrfA) as a D. vulgaris nrfA mutant cannot respire nitrite but remains capable of utilizing nitrite as a nitrogen source. These results illuminate previously uncharacterized metabolic abilities of D. vulgaris that may allow niche expansion in low-sulfate environments. Understanding these abilities may lead to better control of sulfate-reducing bacteria in industrial settings and more accurate prediction of their interactions in the environment.
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Nowka B, Off S, Daims H, Spieck E. Improved isolation strategies allowed the phenotypic differentiation of two Nitrospira strains from widespread phylogenetic lineages. FEMS Microbiol Ecol 2014; 91:fiu031. [DOI: 10.1093/femsec/fiu031] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
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Changes in metabolic pathways of Desulfovibrio alaskensis G20 cells induced by molybdate excess. J Biol Inorg Chem 2014; 20:311-22. [PMID: 25488518 DOI: 10.1007/s00775-014-1224-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 11/25/2014] [Indexed: 01/06/2023]
Abstract
The activity of sulfate-reducing bacteria (SRB) intensifies the problems associated to corrosion of metals and the solution entails significant economic costs. Although molybdate can be used to control the negative effects of these organisms, the mechanisms triggered in the cells exposed to Mo-excess are poorly understood. In this work, the effects of molybdate ions on the growth and morphology of the SRB Desulfovibrio alaskensis G20 (DaG20) were investigated. In addition, the cellular localization, ion uptake and regulation of protein expression were studied. We found that molybdate concentrations ranging between 50 and 150 µM produce a twofold increase in the doubling time with this effect being more significant at 200 µM molybdate (five times increase in the doubling time). It was also observed that 500 µM molybdate completely inhibits the cellular growth. On the context of protein regulation, we found that several enzymes involved in energy metabolism, cellular division and metal uptake processes were particularly influenced under the conditions tested. An overall description of some of the mechanisms involved in the DaG20 adaptation to molybdate-stress conditions is discussed.
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Hao TW, Xiang PY, Mackey HR, Chi K, Lu H, Chui HK, van Loosdrecht MCM, Chen GH. A review of biological sulfate conversions in wastewater treatment. WATER RESEARCH 2014; 65:1-21. [PMID: 25086411 DOI: 10.1016/j.watres.2014.06.043] [Citation(s) in RCA: 180] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Revised: 06/26/2014] [Accepted: 06/30/2014] [Indexed: 06/03/2023]
Abstract
Treatment of waters contaminated with sulfur containing compounds (S) resulting from seawater intrusion, the use of seawater (e.g. seawater flushing, cooling) and industrial processes has become a challenging issue since around two thirds of the world's population live within 150 km of the coast. In the past, research has produced a number of bioengineered systems for remediation of industrial sulfate containing sewage and sulfur contaminated groundwater utilizing sulfate reducing bacteria (SRB). The majority of these studies are specific with SRB only or focusing on the microbiology rather than the engineered application. In this review, existing sulfate based biotechnologies and new approaches for sulfate contaminated waters treatment are discussed. The sulfur cycle connects with carbon, nitrogen and phosphorus cycles, thus a new platform of sulfur based biotechnologies incorporating sulfur cycle with other cycles can be developed, for the removal of sulfate and other pollutants (e.g. carbon, nitrogen, phosphorus and metal) from wastewaters. All possible electron donors for sulfate reduction are summarized for further understanding of the S related biotechnologies including rates and benefits/drawbacks of each electron donor. A review of known SRB and their environmental preferences with regard to bioreactor operational parameters (e.g. pH, temperature, salinity etc.) shed light on the optimization of sulfur conversion-based biotechnologies. This review not only summarizes information from the current sulfur conversion-based biotechnologies for further optimization and understanding, but also offers new directions for sulfur related biotechnology development.
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Affiliation(s)
- Tian-wei Hao
- Department of Civil & Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Peng-yu Xiang
- Department of Civil & Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Hamish R Mackey
- Department of Civil & Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Kun Chi
- Department of Civil & Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Hui Lu
- SYSU-HKUST Joint Research Centre for Innovative Environmental Technology, Sun Yat-sen University, Guangzhou, China
| | - Ho-kwong Chui
- Department of Civil & Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Mark C M van Loosdrecht
- Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC, Delft, The Netherlands
| | - Guang-Hao Chen
- Department of Civil & Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong; SYSU-HKUST Joint Research Centre for Innovative Environmental Technology, Sun Yat-sen University, Guangzhou, China.
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Wilkins MJ, Hoyt DW, Marshall MJ, Alderson PA, Plymale AE, Markillie LM, Tucker AE, Walter ED, Linggi BE, Dohnalkova AC, Taylor RC. CO2 exposure at pressure impacts metabolism and stress responses in the model sulfate-reducing bacterium Desulfovibrio vulgaris strain Hildenborough. Front Microbiol 2014; 5:507. [PMID: 25309528 PMCID: PMC4174866 DOI: 10.3389/fmicb.2014.00507] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 09/09/2014] [Indexed: 12/02/2022] Open
Abstract
Geologic carbon dioxide (CO2) sequestration drives physical and geochemical changes in deep subsurface environments that impact indigenous microbial activities. The combined effects of pressurized CO2 on a model sulfate-reducing microorganism, Desulfovibrio vulgaris, have been assessed using a suite of genomic and kinetic measurements. Novel high-pressure NMR time-series measurements using 13C-lactate were used to track D. vulgaris metabolism. We identified cessation of respiration at CO2 pressures of 10 bar, 25 bar, 50 bar, and 80 bar. Concurrent experiments using N2 as the pressurizing phase had no negative effect on microbial respiration, as inferred from reduction of sulfate to sulfide. Complementary pressurized batch incubations and fluorescence microscopy measurements supported NMR observations, and indicated that non-respiring cells were mostly viable at 50 bar CO2 for at least 4 h, and at 80 bar CO2 for 2 h. The fraction of dead cells increased rapidly after 4 h at 80 bar CO2. Transcriptomic (RNA-Seq) measurements on mRNA transcripts from CO2-incubated biomass indicated that cells up-regulated the production of certain amino acids (leucine, isoleucine) following CO2 exposure at elevated pressures, likely as part of a general stress response. Evidence for other poorly understood stress responses were also identified within RNA-Seq data, suggesting that while pressurized CO2 severely limits the growth and respiration of D. vulgaris cells, biomass retains intact cell membranes at pressures up to 80 bar CO2. Together, these data show that geologic sequestration of CO2 may have significant impacts on rates of sulfate reduction in many deep subsurface environments where this metabolism is a key respiratory process.
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Affiliation(s)
- Michael J Wilkins
- Pacific Northwest National Laboratory, Biological Sciences Division Richland, WA, USA ; Department of Microbiology, School of Earth Sciences, The Ohio State University Columbus, OH, USA
| | - David W Hoyt
- Environmental and Molecular Sciences Laboratory, Pacific Northwest National Laboratory Richland, WA, USA
| | - Matthew J Marshall
- Pacific Northwest National Laboratory, Biological Sciences Division Richland, WA, USA
| | - Paul A Alderson
- Pacific Northwest National Laboratory, Biological Sciences Division Richland, WA, USA
| | - Andrew E Plymale
- Pacific Northwest National Laboratory, Biological Sciences Division Richland, WA, USA
| | - L Meng Markillie
- Environmental and Molecular Sciences Laboratory, Pacific Northwest National Laboratory Richland, WA, USA
| | - Abby E Tucker
- Pacific Northwest National Laboratory, Biological Sciences Division Richland, WA, USA
| | - Eric D Walter
- Environmental and Molecular Sciences Laboratory, Pacific Northwest National Laboratory Richland, WA, USA
| | - Bryan E Linggi
- Environmental and Molecular Sciences Laboratory, Pacific Northwest National Laboratory Richland, WA, USA
| | - Alice C Dohnalkova
- Environmental and Molecular Sciences Laboratory, Pacific Northwest National Laboratory Richland, WA, USA
| | - Ron C Taylor
- Environmental and Molecular Sciences Laboratory, Pacific Northwest National Laboratory Richland, WA, USA
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Yu H, Chen C, Ma J, Liu W, Zhou J, Lee DJ, Ren N, Wang A. GeoChip-based analysis of the microbial community functional structures in simultaneous desulfurization and denitrification process. J Environ Sci (China) 2014; 26:1375-1382. [PMID: 25079984 DOI: 10.1016/j.jes.2014.05.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Revised: 12/02/2013] [Accepted: 12/31/2013] [Indexed: 06/03/2023]
Abstract
The elemental sulfur (S°) recovery was evaluated in the presence of nitrate in two development models of simultaneous desulfurization and denitrification (SDD) process. At the loading rates of 0.9 kg S/(m³·day) for sulfide and 0.4 kg N/(m³·day) for nitrate, S° conversion rate was 91.1% in denitrifying sulfide removal (DSR) model which was higher than in integrated simultaneous desulfurization and denitrification (ISDD) model (25.6%). A comprehensive analysis of functional diversity, structure and metabolic potential of microbial communities was examined in two models by using functional gene array (GeoChip 2.0). GeoChip data indicated that diversity indices, community structure, and abundance of functional genes were distinct between two models. Diversity indices (Simpson's diversity index (1/D) and Shannon-Weaver index (H')) of all detected genes showed that with elevated influent loading rate, the functional diversity decreased in ISDD model but increased in DSR model. In contrast to ISDD model, the overall abundance of dsr genes was lower in DSR model, while some functional genes targeting from nitrate-reducing sulfide-oxidizing bacteria (NR-SOB), such as Thiobacillus denitrificans, Sulfurimonas denitrificans, and Paracoccus pantotrophus were more abundant in DSR model which were highly associated with the change of S(0) conversion rate obtained in two models. The results obtained in this study provide additional insights into the microbial metabolic mechanisms involved in ISDD and DSR models, which in turn will improve the overall performance of SDD process.
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Affiliation(s)
- Hao Yu
- School of Environmental Science and Engineering, Liaoning Technical University, Fuxin 123000, China; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
| | - Chuan Chen
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
| | - Jincai Ma
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | - Wenzong Liu
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Jizhong Zhou
- Institute for Environmental Genomics, Department of Botany and Microbiology, University of Oklahoma, Norman, OK 73019, USA
| | - Duu-Jong Lee
- Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan
| | - Nanqi Ren
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Aijie Wang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China; Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
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Engelbrektson A, Hubbard CG, Tom LM, Boussina A, Jin YT, Wong H, Piceno YM, Carlson HK, Conrad ME, Anderson G, Coates JD. Inhibition of microbial sulfate reduction in a flow-through column system by (per)chlorate treatment. Front Microbiol 2014; 5:315. [PMID: 25071731 PMCID: PMC4092371 DOI: 10.3389/fmicb.2014.00315] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 06/09/2014] [Indexed: 11/13/2022] Open
Abstract
Microbial sulfate reduction is a primary cause of oil reservoir souring. Here we show that amendment with chlorate or perchlorate [collectively (per)chlorate] potentially resolves this issue. Triplicate packed columns inoculated with marine sediment were flushed with coastal water amended with yeast extract and one of nitrate, chlorate, or perchlorate. Results showed that although sulfide production was dramatically reduced by all treatments, effluent sulfide was observed in the nitrate (10 mM) treatment after an initial inhibition period. In contrast, no effluent sulfide was observed with (per)chlorate (10 mM). Microbial community analyses indicated temporal community shifts and phylogenetic clustering by treatment. Nitrate addition stimulated Xanthomonadaceae and Rhizobiaceae growth, supporting their role in nitrate metabolism. (Per)chlorate showed distinct effects on microbial community structure compared with nitrate and resulted in a general suppression of the community relative to the untreated control combined with a significant decrease in sulfate reducing species abundance indicating specific toxicity. Furthermore, chlorate stimulated Pseudomonadaceae and Pseudoalteromonadaceae, members of which are known chlorate respirers, suggesting that chlorate may also control sulfidogenesis by biocompetitive exclusion of sulfate-reduction. Perchlorate addition stimulated Desulfobulbaceae and Desulfomonadaceae, which contain sulfide oxidizing and elemental sulfur-reducing species respectively, suggesting that effluent sulfide concentrations may be controlled through sulfur redox cycling in addition to toxicity and biocompetitive exclusion. Sulfur isotope analyses further support sulfur cycling in the columns, even when sulfide is not detected. This study indicates that (per)chlorate show great promise as inhibitors of sulfidogenesis in natural communities and provides insight into which organisms and respiratory processes are involved.
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Affiliation(s)
- Anna Engelbrektson
- Department of Plant and Microbial Biology, University of California, Berkeley Berkeley, CA, USA
| | | | - Lauren M Tom
- Lawrence Berkeley National Laboratory, Earth Sciences Division Berkeley, CA, USA
| | - Aaron Boussina
- Department of Plant and Microbial Biology, University of California, Berkeley Berkeley, CA, USA
| | - Yong T Jin
- Department of Plant and Microbial Biology, University of California, Berkeley Berkeley, CA, USA
| | - Hayden Wong
- Department of Plant and Microbial Biology, University of California, Berkeley Berkeley, CA, USA
| | - Yvette M Piceno
- Lawrence Berkeley National Laboratory, Earth Sciences Division Berkeley, CA, USA
| | - Hans K Carlson
- Department of Plant and Microbial Biology, University of California, Berkeley Berkeley, CA, USA
| | - Mark E Conrad
- Lawrence Berkeley National Laboratory, Earth Sciences Division Berkeley, CA, USA
| | - Gary Anderson
- Lawrence Berkeley National Laboratory, Earth Sciences Division Berkeley, CA, USA
| | - John D Coates
- Department of Plant and Microbial Biology, University of California, Berkeley Berkeley, CA, USA ; Lawrence Berkeley National Laboratory, Earth Sciences Division Berkeley, CA, USA
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Korte HL, Fels SR, Christensen GA, Price MN, Kuehl JV, Zane GM, Deutschbauer AM, Arkin AP, Wall JD. Genetic basis for nitrate resistance in Desulfovibrio strains. Front Microbiol 2014; 5:153. [PMID: 24795702 PMCID: PMC4001038 DOI: 10.3389/fmicb.2014.00153] [Citation(s) in RCA: 162] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 03/21/2014] [Indexed: 12/31/2022] Open
Abstract
Nitrate is an inhibitor of sulfate-reducing bacteria (SRB). In petroleum production sites, amendments of nitrate and nitrite are used to prevent SRB production of sulfide that causes souring of oil wells. A better understanding of nitrate stress responses in the model SRB, Desulfovibrio vulgaris Hildenborough and Desulfovibrio alaskensis G20, will strengthen predictions of environmental outcomes of nitrate application. Nitrate inhibition of SRB has historically been considered to result from the generation of small amounts of nitrite, to which SRB are quite sensitive. Here we explored the possibility that nitrate might inhibit SRB by a mechanism other than through nitrite inhibition. We found that nitrate-stressed D. vulgaris cultures grown in lactate-sulfate conditions eventually grew in the presence of high concentrations of nitrate, and their resistance continued through several subcultures. Nitrate consumption was not detected over the course of the experiment, suggesting adaptation to nitrate. With high-throughput genetic approaches employing TnLE-seq for D. vulgaris and a pooled mutant library of D. alaskensis, we determined the fitness of many transposon mutants of both organisms in nitrate stress conditions. We found that several mutants, including homologs present in both strains, had a greatly increased ability to grow in the presence of nitrate but not nitrite. The mutated genes conferring nitrate resistance included the gene encoding the putative Rex transcriptional regulator (DVU0916/Dde_2702), as well as a cluster of genes (DVU0251-DVU0245/Dde_0597-Dde_0605) that is poorly annotated. Follow-up studies with individual D. vulgaris transposon and deletion mutants confirmed high-throughput results. We conclude that, in D. vulgaris and D. alaskensis, nitrate resistance in wild-type cultures is likely conferred by spontaneous mutations. Furthermore, the mechanisms that confer nitrate resistance may be different from those that confer nitrite resistance.
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Affiliation(s)
- Hannah L Korte
- Department of Biochemistry, University of Missouri Columbia, MO, USA ; Ecosystems and Networks Integrated with Genes and Molecular Assemblies Berkeley, CA, USA
| | - Samuel R Fels
- Ecosystems and Networks Integrated with Genes and Molecular Assemblies Berkeley, CA, USA ; Department of Molecular Microbiology and Immunology, University of Missouri Columbia, MO, USA
| | - Geoff A Christensen
- Department of Biochemistry, University of Missouri Columbia, MO, USA ; Ecosystems and Networks Integrated with Genes and Molecular Assemblies Berkeley, CA, USA
| | - Morgan N Price
- Ecosystems and Networks Integrated with Genes and Molecular Assemblies Berkeley, CA, USA ; Physical Biosciences Division, Lawrence Berkeley National Laboratory Berkeley, CA, USA
| | - Jennifer V Kuehl
- Ecosystems and Networks Integrated with Genes and Molecular Assemblies Berkeley, CA, USA ; Physical Biosciences Division, Lawrence Berkeley National Laboratory Berkeley, CA, USA
| | - Grant M Zane
- Department of Biochemistry, University of Missouri Columbia, MO, USA ; Ecosystems and Networks Integrated with Genes and Molecular Assemblies Berkeley, CA, USA
| | - Adam M Deutschbauer
- Ecosystems and Networks Integrated with Genes and Molecular Assemblies Berkeley, CA, USA ; Physical Biosciences Division, Lawrence Berkeley National Laboratory Berkeley, CA, USA
| | - Adam P Arkin
- Ecosystems and Networks Integrated with Genes and Molecular Assemblies Berkeley, CA, USA ; Physical Biosciences Division, Lawrence Berkeley National Laboratory Berkeley, CA, USA
| | - Judy D Wall
- Department of Biochemistry, University of Missouri Columbia, MO, USA ; Ecosystems and Networks Integrated with Genes and Molecular Assemblies Berkeley, CA, USA ; Department of Molecular Microbiology and Immunology, University of Missouri Columbia, MO, USA
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Carrino-Kyker SR, Smemo KA, Burke DJ. Shotgun metagenomic analysis of metabolic diversity and microbial community structure in experimental vernal pools subjected to nitrate pulse. BMC Microbiol 2013; 13:78. [PMID: 23574744 PMCID: PMC3629998 DOI: 10.1186/1471-2180-13-78] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Accepted: 04/01/2013] [Indexed: 12/29/2022] Open
Abstract
Background Human activities have greatly increased nitrogen (N) levels in natural habitats through atmospheric N deposition and nutrient leaching, which can have large effects on N cycling and other ecosystem processes. Because of the significant role microorganisms play in N cycling, high inputs of nitrogenous compounds, such as nitrate (NO3-), into natural ecosystems could have cascading effects on microbial community structure and the metabolic processes that microbes perform. To investigate the multiple effects of NO3- pollution on microbial communities, we created two shotgun metagenomes from vernal pool microcosms that were either enriched with a solution of 10 mg NO3--N (+NO3-) or received distilled water as a control (−N). Results After only 20 hours of exposure to NO3-, the initial microbial community had shifted toward one containing a higher proportional abundance of stress tolerance and fermentation environmental gene tags (EGTs). Surprisingly, we found no changes to N metabolism EGTs, even though large shifts in denitrification rates were seen between the +NO3- and –N microcosms. Thus, in the absence of NO3- addition, it is plausible that the microbes used other respiratory pathways for energy. Respiratory pathways involving iron may have been particularly important in our –N microcosms, since iron acquisition EGTs were proportionally higher in the –N metagenome. Additionally, we noted a proportional increase in Acidobacteria and Alphaproteobacteria EGTs in response to NO3- addition. These community shifts in were not evident with TRFLP, suggesting that metagenomic analyses may detect fine-scale changes not possible with community profiling techniques. Conclusions Our results suggest that the vernal pool microbial communities profiled here may rely on their metabolic plasticity for growth and survival when certain resources are limiting. The creation of these metagenomes also highlights how little is known about the effects of NO3- pollution on microbial communities, and the relationship between community stability and function in response to disturbance.
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Hybrid cluster proteins and flavodiiron proteins afford protection to Desulfovibrio vulgaris upon macrophage infection. J Bacteriol 2013; 195:2684-90. [PMID: 23564166 DOI: 10.1128/jb.00074-13] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Desulfovibrio species are Gram-negative anaerobic sulfate-reducing bacteria that colonize the human gut. Recently, Desulfovibrio spp. have been implicated in gastrointestinal diseases and shown to stimulate the epithelial immune response, leading to increased production of inflammatory cytokines by macrophages. Activated macrophages are key cells of the immune system that impose nitrosative stress during phagocytosis. Hence, we have analyzed the in vitro and in vivo responses of Desulfovibrio vulgaris Hildenborough to nitric oxide (NO) and the role of the hybrid cluster proteins (HCP1 and HCP2) and rubredoxin oxygen oxidoreductases (ROO1 and ROO2) in NO protection. Among the four genes, hcp2 was the gene most highly induced by NO, and the hcp2 transposon mutant exhibited the lowest viability under conditions of NO stress. Studies in murine macrophages revealed that D. vulgaris survives incubation with these phagocytes and triggers NO production at levels similar to those stimulated by the cytokine gamma interferon (IFN-γ). Furthermore, D. vulgaris hcp and roo mutants exhibited reduced viability when incubated with macrophages, revealing that these gene products contribute to the survival of D. vulgaris during macrophage infection.
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Clark ME, He Z, Redding AM, Joachimiak MP, Keasling JD, Zhou JZ, Arkin AP, Mukhopadhyay A, Fields MW. Transcriptomic and proteomic analyses of Desulfovibrio vulgaris biofilms: carbon and energy flow contribute to the distinct biofilm growth state. BMC Genomics 2012; 13:138. [PMID: 22507456 PMCID: PMC3431258 DOI: 10.1186/1471-2164-13-138] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Accepted: 02/27/2012] [Indexed: 11/10/2022] Open
Abstract
Background Desulfovibrio vulgaris Hildenborough is a sulfate-reducing bacterium (SRB) that is intensively studied in the context of metal corrosion and heavy-metal bioremediation, and SRB populations are commonly observed in pipe and subsurface environments as surface-associated populations. In order to elucidate physiological changes associated with biofilm growth at both the transcript and protein level, transcriptomic and proteomic analyses were done on mature biofilm cells and compared to both batch and reactor planktonic populations. The biofilms were cultivated with lactate and sulfate in a continuously fed biofilm reactor, and compared to both batch and reactor planktonic populations. Results The functional genomic analysis demonstrated that biofilm cells were different compared to planktonic cells, and the majority of altered abundances for genes and proteins were annotated as hypothetical (unknown function), energy conservation, amino acid metabolism, and signal transduction. Genes and proteins that showed similar trends in detected levels were particularly involved in energy conservation such as increases in an annotated ech hydrogenase, formate dehydrogenase, pyruvate:ferredoxin oxidoreductase, and rnf oxidoreductase, and the biofilm cells had elevated formate dehydrogenase activity. Several other hydrogenases and formate dehydrogenases also showed an increased protein level, while decreased transcript and protein levels were observed for putative coo hydrogenase as well as a lactate permease and hyp hydrogenases for biofilm cells. Genes annotated for amino acid synthesis and nitrogen utilization were also predominant changers within the biofilm state. Ribosomal transcripts and proteins were notably decreased within the biofilm cells compared to exponential-phase cells but were not as low as levels observed in planktonic, stationary-phase cells. Several putative, extracellular proteins (DVU1012, 1545) were also detected in the extracellular fraction from biofilm cells. Conclusions Even though both the planktonic and biofilm cells were oxidizing lactate and reducing sulfate, the biofilm cells were physiologically distinct compared to planktonic growth states due to altered abundances of genes/proteins involved in carbon/energy flow and extracellular structures. In addition, average expression values for multiple rRNA transcripts and respiratory activity measurements indicated that biofilm cells were metabolically more similar to exponential-phase cells although biofilm cells are structured differently. The characterization of physiological advantages and constraints of the biofilm growth state for sulfate-reducing bacteria will provide insight into bioremediation applications as well as microbially-induced metal corrosion.
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Affiliation(s)
- Melinda E Clark
- Center for Biofilm Engineering, Montana State University, Bozeman, USA
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Functional characterization of Crp/Fnr-type global transcriptional regulators in Desulfovibrio vulgaris Hildenborough. Appl Environ Microbiol 2011; 78:1168-77. [PMID: 22156435 DOI: 10.1128/aem.05666-11] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Crp/Fnr-type global transcriptional regulators regulate various metabolic pathways in bacteria and typically function in response to environmental changes. However, little is known about the function of four annotated Crp/Fnr homologs (DVU0379, DVU2097, DVU2547, and DVU3111) in Desulfovibrio vulgaris Hildenborough. A systematic study using bioinformatic, transcriptomic, genetic, and physiological approaches was conducted to characterize their roles in stress responses. Similar growth phenotypes were observed for the crp/fnr deletion mutants under multiple stress conditions. Nevertheless, the idea of distinct functions of Crp/Fnr-type regulators in stress responses was supported by phylogeny, gene transcription changes, fitness changes, and physiological differences. The four D. vulgaris Crp/Fnr homologs are localized in three subfamilies (HcpR, CooA, and cc). The crp/fnr knockout mutants were well separated by transcriptional profiling using detrended correspondence analysis (DCA), and more genes significantly changed in expression in a ΔDVU3111 mutant (JW9013) than in the other three paralogs. In fitness studies, strain JW9013 showed the lowest fitness under standard growth conditions (i.e., sulfate reduction) and the highest fitness under NaCl or chromate stress conditions; better fitness was observed for a ΔDVU2547 mutant (JW9011) under nitrite stress conditions and a ΔDVU2097 mutant (JW9009) under air stress conditions. A higher Cr(VI) reduction rate was observed for strain JW9013 in experiments with washed cells. These results suggested that the four Crp/Fnr-type global regulators play distinct roles in stress responses of D. vulgaris. DVU3111 is implicated in responses to NaCl and chromate stresses, DVU2547 in nitrite stress responses, and DVU2097 in air stress responses.
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Biological souring and mitigation in oil reservoirs. Appl Microbiol Biotechnol 2011; 92:263-82. [DOI: 10.1007/s00253-011-3542-6] [Citation(s) in RCA: 211] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2011] [Revised: 07/29/2011] [Accepted: 08/05/2011] [Indexed: 02/07/2023]
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Keuter S, Kruse M, Lipski A, Spieck E. Relevance of Nitrospira for nitrite oxidation in a marine recirculation aquaculture system and physiological features of a Nitrospira marina-like isolate. Environ Microbiol 2011; 13:2536-47. [DOI: 10.1111/j.1462-2920.2011.02525.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Mohanakrishnan J, Kofoed MVW, Barr J, Yuan Z, Schramm A, Meyer RL. Dynamic microbial response of sulfidogenic wastewater biofilm to nitrate. Appl Microbiol Biotechnol 2011; 91:1647-57. [DOI: 10.1007/s00253-011-3330-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2011] [Revised: 03/07/2011] [Accepted: 04/10/2011] [Indexed: 10/18/2022]
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How sulphate-reducing microorganisms cope with stress: lessons from systems biology. Nat Rev Microbiol 2011; 9:452-66. [PMID: 21572460 DOI: 10.1038/nrmicro2575] [Citation(s) in RCA: 120] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Sulphate-reducing microorganisms (SRMs) are a phylogenetically diverse group of anaerobes encompassing distinct physiologies with a broad ecological distribution. As SRMs have important roles in the biogeochemical cycling of carbon, nitrogen, sulphur and various metals, an understanding of how these organisms respond to environmental stresses is of fundamental and practical importance. In this Review, we highlight recent applications of systems biology tools in studying the stress responses of SRMs, particularly Desulfovibrio spp., at the cell, population, community and ecosystem levels. The syntrophic lifestyle of SRMs is also discussed, with a focus on system-level analyses of adaptive mechanisms. Such information is important for understanding the microbiology of the global sulphur cycle and for developing biotechnological applications of SRMs for environmental remediation, energy production, biocorrosion control, wastewater treatment and mineral recovery.
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An HcpR homologue from Desulfovibrio desulfuricans and its possible role in nitrate reduction and nitrosative stress. Biochem Soc Trans 2011; 39:224-9. [PMID: 21265778 DOI: 10.1042/bst0390224] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The Escherichia coli CRP (cAMP receptor protein), is a global regulator of transcription that modulates gene expression by activation or repression at a range of promoters in E. coli. A major function is to regulate the selection of nutrients required for growth. The anaerobic sulfate-reducing bacterium Desulfovibrio desulfuricans ATCC27774 is capable of utilizing sulfate, nitrite and nitrate as terminal electron acceptors. In the presence of both sulfate and nitrate, sulfate is reduced preferentially despite nitrate being the thermodynamically more favourable electron acceptor. Three inverted repeat sequences upstream of the D. desulfuricans ATCC27774 nap (nitrate reduction in the periplasm) operon have high levels of similarity to the consensus sequence for the E. coli CRP DNA-binding site. In other Desulfovibrio species a putative CRP homologue, HcpR [regulator of hcp (hybrid cluster protein) transcription], has a predicted regulon comprising genes involved in sulfate reduction and nitrosative stress. The presence of CRP consensus sites within the D. desulfuricans ATCC27774 nap promoter prompted a search for CRP homologues in the genomes of sulfate-reducing bacteria. This revealed the presence of a potential CRP homologue that we predict binds to CRP consensus sites such as those of the nap operon. Furthermore, we predict that much of the core HcpR regulon predicted in other Desulfovibrio species is conserved in D. desulfuricans.
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