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Obayori OS, Salam LB, Ashade AO, Oseni TD, Kalu MD, Mustapha FM. An animal charcoal contaminated cottage industry soil highlighted by halophilic archaea dominance and decimation of bacteria. World J Microbiol Biotechnol 2024; 40:327. [PMID: 39299940 DOI: 10.1007/s11274-024-04136-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2024] [Accepted: 09/09/2024] [Indexed: 09/22/2024]
Abstract
An animal charcoal contaminated cottage industry soil in Lagos, Nigeria (ACGT) was compared in an ex post facto study with a nearby unimpacted soil (ACGC). Hydrocarbon content was higher than regulatory limits in ACGT (180.2 mg/kg) but lower in ACGC (19.28 mg/kg). Heavy metals like nickel, cadmium, chromium and lead were below detection limit in ACGC. However, all these metals, except cadmium, were detected in ACGT, but at concentrations below regulatory limits. Furthermore, copper (253.205 mg/kg) and zinc (422.630 mg/kg) were above regulatory limits in ACGT. Next generation sequencing revealed that the procaryotic community was dominated by bacteria in ACGC (62%) while in ACGT archaea dominated (76%). Dominant phyla in ACGC were Euryarchaeota (37%), Pseudomonadota (16%) and Actinomycetota (12%). In ACGT it was Euryarchaeota (76%), Bacillota (9%), Pseudomonadota (7%) and Candidatus Nanohaloarchaeota (5%). Dominant Halobacteria genera in ACGT were Halobacterium (16%), Halorientalis (16%), unranked halophilic archaeon (13%) Salarchaeum (6%) and Candidatus Nanohalobium (5%), whereas ACGC showed greater diversity dominated by bacterial genera Salimicrobium (7%) and Halomonas (3%). Heavy metals homeostasis genes, especially for copper, were fairly represented in both soils but with bacterial taxonomic affiliations. Sites like ACGT, hitherto poorly studied and understood, could be sources of novel bioresources.
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Affiliation(s)
| | - Lateef Babatunde Salam
- Microbiology Unit, Department of Biological Sciences, Elizade University, Ilara-Mokin, Ondo State, Nigeria
| | - Ahmeed Olalekan Ashade
- Department of Microbiology, Faculty of Science, Lagos State University, Ojo, Lagos, Nigeria
| | | | - Mandy Divine Kalu
- Department of Microbiology, Faculty of Science, Lagos State University, Ojo, Lagos, Nigeria
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Bullows JE, Kanak A, Shedrick L, Kiessling C, Aklujkar M, Kostka J, Chin KJ. Anaerobic benzene oxidation in Geotalea daltonii involves activation by methylation and is regulated by the transition state regulator AbrB. Appl Environ Microbiol 2024:e0085624. [PMID: 39287397 DOI: 10.1128/aem.00856-24] [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: 05/01/2024] [Accepted: 08/18/2024] [Indexed: 09/19/2024] Open
Abstract
Benzene is a widespread groundwater contaminant that persists under anoxic conditions. The aim of this study was to more accurately investigate anaerobic microbial degradation pathways to predict benzene fate and transport. Preliminary genomic analysis of Geotalea daltonii strain FRC-32, isolated from contaminated groundwater, revealed the presence of putative aromatic-degrading genes. G. daltonii was subsequently shown to conserve energy for growth on benzene as the sole electron donor and fumarate or nitrate as the electron acceptor. The hbs gene, encoding for 3-hydroxybenzylsuccinate synthase (Hbs), a homolog of the radical-forming, toluene-activating benzylsuccinate synthase (Bss), was upregulated during benzene oxidation in G. daltonii, while the bss gene was upregulated during toluene oxidation. Addition of benzene to the G. daltonii whole-cell lysate resulted in toluene formation, indicating that methylation of benzene was occurring. Complementation of σ54- (deficient) E. coli transformed with the bss operon restored its ability to grow in the presence of toluene, revealing bss to be regulated by σ54. Binding sites for σ70 and the transition state regulator AbrB were identified in the promoter region of the σ54-encoding gene rpoN, and binding was confirmed. Induced expression of abrB during benzene and toluene degradation caused G. daltonii cultures to transition to the death phase. Our results suggested that G. daltonii can anaerobically oxidize benzene by methylation, which is regulated by σ54 and AbrB. Our findings further indicated that the benzene, toluene, and benzoate degradation pathways converge into a single metabolic pathway, representing a uniquely efficient approach to anaerobic aromatic degradation in G. daltonii. IMPORTANCE The contamination of anaerobic subsurface environments including groundwater with toxic aromatic hydrocarbons, specifically benzene, toluene, ethylbenzene, and xylene, has become a global issue. Subsurface groundwater is largely anoxic, and further study is needed to understand the natural attenuation of these compounds. This study elucidated a metabolic pathway utilized by the bacterium Geotalea daltonii capable of anaerobically degrading the recalcitrant molecule benzene using a unique activation mechanism involving methylation. The identification of aromatic-degrading genes and AbrB as a regulator of the anaerobic benzene and toluene degradation pathways provides insights into the mechanisms employed by G. daltonii to modulate metabolic pathways as necessary to thrive in anoxic contaminated groundwater. Our findings contribute to the understanding of novel anaerobic benzene degradation pathways that could potentially be harnessed to develop improved strategies for bioremediation of groundwater contaminants.
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Affiliation(s)
- James E Bullows
- Department of Biology, Georgia State University, Atlanta, Georgia, USA
| | - Alison Kanak
- Department of Biology, Georgia State University, Atlanta, Georgia, USA
| | - Lawrence Shedrick
- Department of Biology, Georgia State University, Atlanta, Georgia, USA
| | | | - Muktak Aklujkar
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts, USA
| | - Joel Kostka
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
- Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Kuk-Jeong Chin
- Department of Biology, Georgia State University, Atlanta, Georgia, USA
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Kaplieva-Dudek I, Samak NA, Bormann J, Kaschani F, Kaiser M, Meckenstock RU. Characterization of 2-phenanthroate:CoA ligase from the sulfate-reducing, phenanthrene-degrading enrichment culture TRIP. Appl Environ Microbiol 2024:e0129624. [PMID: 39248461 DOI: 10.1128/aem.01296-24] [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: 07/03/2024] [Accepted: 08/01/2024] [Indexed: 09/10/2024] Open
Abstract
Polycyclic aromatic hydrocarbons (PAHs) are chemically stable pollutants that are poorly degraded by microorganisms in anoxic sediments. The anaerobic degradation pathway of PAHs such as phenanthrene starts with a carboxylation reaction forming phenanthroic acid. In this study, we identified and characterized the next enzyme in the pathway, the 2-phenanthroate:CoA ligase involved in the ATP-dependent formation of 2-phenanthroyl-CoA from cell-free extracts of the sulfate-reducing enrichment culture TRIP grown anaerobically with phenanthrene. The identified gene sequence indicated that 2-phenanthroate:CoA ligase belongs to the phenylacetate:CoA ligase-like enzyme family. Based on the sequence, we predict a two-domain structure of the 2-phenanthroate:CoA ligase with a typical large N-terminal and a smaller C-terminal domain. Partial purification of 2-phenanthroate:CoA ligase allowed us to identify the coding gene in the genome. 2-Phenanthroate:CoA ligase gene was heterologously expressed in Escherichia coli. Characterization of the 2-phenanthroate:CoA ligase was performed using the partially purified enzyme from cell-free extract and the purified recombinant enzyme. Testing all possible phenanthroic acid isomers as substrate for the ligase reaction showed that 2-phenanthroic acid is the preferred substrate and only 3-phenanthroic acid can be utilized to a minor extent. This also suggests that the product of the prior carboxylase reaction is 2-phenanthroic acid. 2-Phenanthroate:CoA ligase has an optimal activity at pH 7.5 and is oxygen-insensitive, analogous to other aryl-CoA ligases. In contrast to aryl-Coenzyme A ligases reported in the literature, which need Mg2+ as cofactor, 2-phenanthroate:CoA ligase showed greatest activity with a combination of 5 mM MgCl2 and 5 mM KCl. Furthermore, a substrate inhibition was observed at ATP concentrations above 1 mM and the enzyme was also active with ADP. IMPORTANCE Polycyclic aromatic hydrocarbons (PAHs) constitute a class of very toxic and persistent pollutants in the environment. However, the anaerobic degradation of three-ring PAHs such as phenanthrene is barely investigated. The initial degradation step starts with a carboxylation followed by a CoA‑thioesterification reaction performed by an aryl-CoA ligase. The formation of a CoA-thioester is an important step in the degradation pathway of aromatic compounds because the CoA-ester is needed for all downstream biochemical reactions in the pathway. Furthermore, we provide biochemical proof for the identification of the first genes for anaerobic phenanthrene degradation. Results presented here provide information about the biochemical and structural properties of the purified 2‑phenanthroate:CoA ligase and expand our knowledge of aryl-CoA ligases.
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Affiliation(s)
- I Kaplieva-Dudek
- Environmental Microbiology and Biotechnology (EMB), Aquatic Microbiology, Faculty of Chemistry, University of Duisburg-Essen, Essen, Germany
| | - Nadia A Samak
- Environmental Microbiology and Biotechnology (EMB), Aquatic Microbiology, Faculty of Chemistry, University of Duisburg-Essen, Essen, Germany
| | - Jenny Bormann
- Department of Chemical Biology, ZMB, Faculty of Biology, University of Duisburg-Essen, Essen, Germany
- Analytics Core Facility Essen, ZMB, Faculty of Biology, University of Duisburg-Essen, Essen, Germany
| | - Farnusch Kaschani
- Department of Chemical Biology, ZMB, Faculty of Biology, University of Duisburg-Essen, Essen, Germany
- Analytics Core Facility Essen, ZMB, Faculty of Biology, University of Duisburg-Essen, Essen, Germany
| | - Markus Kaiser
- Department of Chemical Biology, ZMB, Faculty of Biology, University of Duisburg-Essen, Essen, Germany
| | - Rainer U Meckenstock
- Environmental Microbiology and Biotechnology (EMB), Aquatic Microbiology, Faculty of Chemistry, University of Duisburg-Essen, Essen, Germany
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Li Y, Liu Y, Guo D, Dong H. Differential degradation of petroleum hydrocarbons by Shewanella putrefaciens under aerobic and anaerobic conditions. Front Microbiol 2024; 15:1389954. [PMID: 38659987 PMCID: PMC11040095 DOI: 10.3389/fmicb.2024.1389954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Accepted: 03/27/2024] [Indexed: 04/26/2024] Open
Abstract
The complexity of crude oil composition, combined with the fluctuating oxygen level in contaminated environments, poses challenges for the bioremediation of oil pollutants, because of compound-specific microbial degradation of petroleum hydrocarbons under certain conditions. As a result, facultative bacteria capable of breaking down petroleum hydrocarbons under both aerobic and anaerobic conditions are presumably effective, however, this hypothesis has not been directly tested. In the current investigation, Shewanella putrefaciens CN32, a facultative anaerobic bacterium, was used to degrade petroleum hydrocarbons aerobically (using O2 as an electron acceptor) and anaerobically (using Fe(III) as an electron acceptor). Under aerobic conditions, CN32 degraded more saturates (65.65 ± 0.01%) than aromatics (43.86 ± 0.03%), with the following order of degradation: dibenzofurans > n-alkanes > biphenyls > fluorenes > naphthalenes > alkylcyclohexanes > dibenzothiophenes > phenanthrenes. In contrast, under anaerobic conditions, CN32 exhibited a higher degradation of aromatics (53.94 ± 0.02%) than saturates (23.36 ± 0.01%), with the following order of degradation: dibenzofurans > fluorenes > biphenyls > naphthalenes > dibenzothiophenes > phenanthrenes > n-alkanes > alkylcyclohexanes. The upregulation of 4-hydroxy-3-polyprenylbenzoate decarboxylase (ubiD), which plays a crucial role in breaking down resistant aromatic compounds, was correlated with the anaerobic degradation of aromatics. At the molecular level, CN32 exhibited a higher efficiency in degrading n-alkanes with low and high carbon numbers relative to those with medium carbon chain lengths. In addition, the degradation of polycyclic aromatic hydrocarbons (PAHs) under both aerobic and anaerobic conditions became increasingly difficult with increased numbers of benzene rings and methyl groups. This study offers a potential solution for the development of targeted remediation of pollutants under oscillating redox conditions.
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Affiliation(s)
- Yang Li
- Center for Geomicrobiology and Biogeochemistry Research, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing, China
- School of Earth Sciences and Resources, China University of Geosciences, Beijing, China
| | - Yuan Liu
- Center for Geomicrobiology and Biogeochemistry Research, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing, China
- School of Earth Sciences and Resources, China University of Geosciences, Beijing, China
| | - Dongyi Guo
- Center for Geomicrobiology and Biogeochemistry Research, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing, China
| | - Hailiang Dong
- Center for Geomicrobiology and Biogeochemistry Research, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing, China
- School of Earth Sciences and Resources, China University of Geosciences, Beijing, China
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Zhou N, Guo H, Zhang Z, Wang H. The discrepant metabolic pathways of PAHs by facultative anaerobic bacteria under aerobic and nitrate-reducing conditions. CHEMOSPHERE 2024; 351:141230. [PMID: 38237784 DOI: 10.1016/j.chemosphere.2024.141230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 01/07/2024] [Accepted: 01/14/2024] [Indexed: 01/28/2024]
Abstract
Studies regarding the facultative anaerobic biodegradation of polycyclic aromatic hydrocarbons (PAHs) were still in the initial stage. In this study, a facultative anaerobe which was identified as Bacillus Firmus and named as PheN7 was firstly isolated from the mixed petroleum-polluted soil samples using phenanthrene and nitrate as the solo carbon resource and electron acceptor under anaerobic condition. The degradation rates of PheN7 towards phenanthrene were detected as 33.17 μM/d, 13.81 μM/d and 7.11 μM/d at the initial phenanthrene concentration of 250.17 μM with oxygen, nitrate and sulfate as the electron acceptor, respectively. The metabolic pathways toward phenanthrene by PheN7 were deduced combining the metagenome analysis of PheN7 and intermediate metabolites of phenanthrene under aerobic and nitrate-reducing conditions. Dioxygenation and carboxylation were inferred as the initial activation reactions of phenanthrene degradation in these two pathways. This study highlighted the significance of facultative anaerobic bacteria in natural PAHs biodegradation, revealing the discrepant metabolic fates of PAHs by one solo bacteria under aerobic and anaerobic environments.
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Affiliation(s)
- Nan Zhou
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, China
| | - Haijiao Guo
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, China
| | - Zuotao Zhang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, China
| | - Hui Wang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, China.
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Chen Q, Li Z, Chen Y, Liu M, Yang Q, Zhu B, Mu J, Feng L, Chen Z. Effects of electron acceptors and donors on anaerobic biodegradation of PAHs in marine sediments. MARINE POLLUTION BULLETIN 2024; 199:115925. [PMID: 38113802 DOI: 10.1016/j.marpolbul.2023.115925] [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: 09/05/2023] [Revised: 12/06/2023] [Accepted: 12/10/2023] [Indexed: 12/21/2023]
Abstract
Polycyclic aromatic hydrocarbons (PAHs) are typical organic pollutants accumulated in the environment. PAHs' bioremediation in sediments can be promoted by adding electron acceptor (EA) and electron donor (ED). Bicarbonate and sulfate were chosen as two EAs, and acetate and lactate were selected as two EDs. Six groups of amendments were added into the sediments to access their role in the anaerobic biodegradation of five PAHs, containing phenanthrene, anthracene, fluoranthene, pyrene, and benzo[a]pyrene. The concentrations of PAHs, EAs and EDs, electron transport system activity, and microbial diversity were analyzed during 126-day biodegradation in serum bottles. The HA group (bicarbonate and acetate) achieved the maximum PAH degradation efficiency of 89.67 %, followed by the SL group (sulfate and lactate) with 87.10 %. As the main PAHs degrading bacteria, the abundance of Marinobacter in H group was 8.62 %, and the addition of acetate significantly increased the abundance of Marinobacter in the HA group by 75.65 %.
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Affiliation(s)
- Qingguo Chen
- Zhejiang Key Laboratory of Petrochemical Environmental Pollution, Zhejiang Ocean University, Zhoushan 316022, PR China; National & local Joint Engineering Research Center of Harbor Oil & Gas Storage and Transportation Technology, Zhejiang Ocean University, Zhoushan 316022, PR China
| | - Zhenzhen Li
- Zhejiang Key Laboratory of Petrochemical Environmental Pollution, Zhejiang Ocean University, Zhoushan 316022, PR China; School of Marine Science & Technology, Zhejiang Ocean University, Zhoushan 316022, PR China
| | - Yu Chen
- Zhejiang Key Laboratory of Petrochemical Environmental Pollution, Zhejiang Ocean University, Zhoushan 316022, PR China; School of Marine Science & Technology, Zhejiang Ocean University, Zhoushan 316022, PR China
| | - Mei Liu
- Zhejiang Key Laboratory of Petrochemical Environmental Pollution, Zhejiang Ocean University, Zhoushan 316022, PR China
| | - Qiao Yang
- Zhejiang Key Laboratory of Petrochemical Environmental Pollution, Zhejiang Ocean University, Zhoushan 316022, PR China
| | - Baikang Zhu
- Zhejiang Key Laboratory of Petrochemical Environmental Pollution, Zhejiang Ocean University, Zhoushan 316022, PR China; National & local Joint Engineering Research Center of Harbor Oil & Gas Storage and Transportation Technology, Zhejiang Ocean University, Zhoushan 316022, PR China
| | - Jun Mu
- College of Ecology and Environment, Hainan Tropical Ocean University, Sanya 572022, PR China.
| | - Lijuan Feng
- Zhejiang Key Laboratory of Petrochemical Environmental Pollution, Zhejiang Ocean University, Zhoushan 316022, PR China; National & local Joint Engineering Research Center of Harbor Oil & Gas Storage and Transportation Technology, Zhejiang Ocean University, Zhoushan 316022, PR China
| | - Zhi Chen
- Department of Building, Civil and Environmental Engineering, Faculty of Engineering & Computer Sciences, Concordia University, Montreal, Quebec H3G1M8, Canada
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Zhang Z, Sun J, Gong X, Wang C, Wang H. Anaerobic biodegradation of pyrene and benzo[a]pyrene by a new sulfate-reducing Desulforamulus aquiferis strain DSA. JOURNAL OF HAZARDOUS MATERIALS 2023; 459:132053. [PMID: 37482040 DOI: 10.1016/j.jhazmat.2023.132053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 06/23/2023] [Accepted: 07/11/2023] [Indexed: 07/25/2023]
Abstract
The study of anaerobic high molecular weight polycyclic aromatic hydrocarbons (HMW-PAHs) biodegradation under sulfate-reducing conditions by microorganisms, including microbial species responsible for biodegradation and relative metabolic processes, remains in its infancy. Here, we found that a new sulfate-reducer, designated as Desulforamulus aquiferis strain DSA, could biodegrade pyrene and benzo[a]pyrene (two kinds of HMW-PAHs) coupled with the reduction of sulfate to sulfide. Interestingly, strain DSA could simultaneously biodegrade pyrene and benzo[a]pyrene when they co-existed in culture. Additionally, the metabolic processes for anaerobic pyrene and benzo[a]pyrene biodegradation by strain DSA were newly proposed in this study based on the detection of intermediates, quantum chemical calculations and analyses of the genome and RTqPCR. The initial activation step for anaerobic pyrene and benzo[a]pyrene biodegradation by strain DSA was identified as the formation of pyrene-2-carboxylic acid and benzo[a]pyrene-11-carboxylic acid by carboxylation Thereafter, CoA ligase, ring reduction through hydrogenation, and ring cracking occurred, and short-chain fatty acids and carbon dioxide were identified as the final products. Additionally, DSA could also utilize benzene, naphthalene, anthracene, phenanthrene, and benz[a]anthracene as carbon sources. Our study can provide new guidance for the anaerobic HMW-PAHs biodegradation under sulfate-reducing conditions.
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Affiliation(s)
- Zuotao Zhang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Jiao Sun
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Xiaoqiang Gong
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Chongyang Wang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Hui Wang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
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Zehnle H, Otersen C, Benito Merino D, Wegener G. Potential for the anaerobic oxidation of benzene and naphthalene in thermophilic microorganisms from the Guaymas Basin. Front Microbiol 2023; 14:1279865. [PMID: 37840718 PMCID: PMC10570749 DOI: 10.3389/fmicb.2023.1279865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Accepted: 09/13/2023] [Indexed: 10/17/2023] Open
Abstract
Unsubstituted aromatic hydrocarbons (UAHs) are recalcitrant molecules abundant in crude oil, which is accumulated in subsurface reservoirs and occasionally enters the marine environment through natural seepage or human-caused spillage. The challenging anaerobic degradation of UAHs by microorganisms, in particular under thermophilic conditions, is poorly understood. Here, we established benzene- and naphthalene-degrading cultures under sulfate-reducing conditions at 50°C and 70°C from Guaymas Basin sediments. We investigated the microorganisms in the enrichment cultures and their potential for UAH oxidation through short-read metagenome sequencing and analysis. Dependent on the combination of UAH and temperature, different microorganisms became enriched. A Thermoplasmatota archaeon was abundant in the benzene-degrading culture at 50°C, but catabolic pathways remained elusive, because the archaeon lacked most known genes for benzene degradation. Two novel species of Desulfatiglandales bacteria were strongly enriched in the benzene-degrading culture at 70°C and in the naphthalene-degrading culture at 50°C. Both bacteria encode almost complete pathways for UAH degradation and for downstream degradation. They likely activate benzene via methylation, and naphthalene via direct carboxylation, respectively. The two species constitute the first thermophilic UAH degraders of the Desulfatiglandales. In the naphthalene-degrading culture incubated at 70°C, a Dehalococcoidia bacterium became enriched, which encoded a partial pathway for UAH degradation. Comparison of enriched bacteria with related genomes from environmental samples indicated that pathways for benzene degradation are widely distributed, while thermophily and capacity for naphthalene activation are rare. Our study highlights the capacities of uncultured thermophilic microbes for UAH degradation in petroleum reservoirs and in contaminated environments.
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Affiliation(s)
- Hanna Zehnle
- Max Planck Institute for Marine Microbiology, Bremen, Germany
- MARUM, Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany
- Faculty of Geosciences, University of Bremen, Bremen, Germany
| | - Carolin Otersen
- Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - David Benito Merino
- Max Planck Institute for Marine Microbiology, Bremen, Germany
- Faculty of Geosciences, University of Bremen, Bremen, Germany
| | - Gunter Wegener
- Max Planck Institute for Marine Microbiology, Bremen, Germany
- MARUM, Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany
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Nathani NM, Mootapally C, Sharma P, Solomon S, Kumar R, Fulke AB, Kumar M. Microbial machinery dealing diverse aromatic compounds: Decoded from pelagic sediment ecogenomics in the gulfs of Kathiawar Peninsula and Arabian Sea. ENVIRONMENTAL RESEARCH 2023; 225:115603. [PMID: 36863652 DOI: 10.1016/j.envres.2023.115603] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Revised: 02/16/2023] [Accepted: 02/28/2023] [Indexed: 05/25/2023]
Abstract
Aromatic hydrocarbons are persistent pollutants in aquatic systems as endocrine disruptors, significantly impacting natural ecosystems and human health. Microbes perform as natural bioremediators to remove and regulate aromatic hydrocarbons in the marine ecosystem. The present study focuses upon the comparative diversity and abundance of various hydrocarbon-degrading enzymes and their pathways from deep sediments along the Gulf of Kathiawar Peninsula and Arabian Sea, India. The elucidation of large number of degradation pathways in the study area under the presence of a wide range of pollutants whose fate needs to be addressed. Sediment core samples were collected, and the whole microbiome was sequenced. Analysis of the predicted ORFs (open reading frames) against the AromaDeg database revealed 2946 aromatic hydrocarbon-degrading enzyme sequences. Statistical analysis portrayed that the Gulfs were more diverse in degradation pathways compared to the open sea, with the Gulf of Kutch being more prosperous and more diverse than the Gulf of Cambay. The vast majority of the annotated ORFs belonged to groups of dioxygenases that included catechol, gentisate, and benzene dioxygenases, along with Rieske (2Fe-2S) and vicinal oxygen chelate (VOC) family proteins. From the sampling sites, only 960 of the total predicted genes were given taxonomic annotations, which mention the presence of many under-explored marine microorganism-derived hydrocarbon degrading genes and pathways. Through the present study, we tried to unveil the array of catabolic pathways of aromatic hydrocarbon degradation and genes from a marine ecosystem that upholds economic and ecological significance in India. Thus, this study provides vast opportunities and strategies for microbial resource recovery in marine ecosystems, which can be investigated to explore aromatic hydrocarbon degradation and their potential mechanisms under various oxic or anoxic environments. Future studies should focus on aromatic hydrocarbon degradation by considering degradation pathways, biochemical analysis, enzymatic, metabolic, and genetic systems, and regulations.
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Affiliation(s)
- Neelam M Nathani
- School of Applied Sciences & Technology (SAST-GTU), Gujarat Technological University, Ahmedabad, 382424, Gujarat, India; Department of Life Sciences, Maharaja Krishnakumarsinhji Bhavnagar University, Bhavnagar, 364001, Gujarat, India
| | - Chandrashekar Mootapally
- School of Applied Sciences & Technology (SAST-GTU), Gujarat Technological University, Ahmedabad, 382424, Gujarat, India; Department of Marine Science, Maharaja Krishnakumarsinhji Bhavnagar University, Bhavnagar, 364001, Gujarat, India
| | - Parth Sharma
- School of Applied Sciences & Technology (SAST-GTU), Gujarat Technological University, Ahmedabad, 382424, Gujarat, India
| | - Solly Solomon
- Department of Marine Biology, Microbiology and Biochemistry, School of Marine Sciences, Cochin University of Science & Technology, Kochi, 682022, Kerala, India; Cochin Base of Fishery Survey of India, Post Box 853 Kochangady, Cochin, 682005, Kerala, India
| | - Rakesh Kumar
- School of Ecology and Environment Studies, Nalanda University, Rajgir, 803116, Bihar, India
| | - Abhay B Fulke
- Microbiology Division, CSIR - National Institute of Oceanography (CSIR-NIO), Regional Centre, Andheri (West), Maharashtra, 400053, India
| | - Manish Kumar
- Sustainability Cluster, University of Petroleum & Energy Studies, Dehradun, Uttarakhand, 248007, India; Escuela de Ingeniería y Ciencias, Tecnologico de Monterrey, Campus Monterey, Monterrey, 64849, Nuevo Leon, Mexico.
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Chen C, Zhang Z, Xu P, Hu H, Tang H. Anaerobic biodegradation of polycyclic aromatic hydrocarbons. ENVIRONMENTAL RESEARCH 2023; 223:115472. [PMID: 36773640 DOI: 10.1016/j.envres.2023.115472] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 01/25/2023] [Accepted: 02/08/2023] [Indexed: 06/18/2023]
Abstract
Although many anaerobic microorganisms that can degrade PAHs have been harnessed, there is still a large gap between laboratory achievements and practical applications. Here, we review the recent advances in the biodegradation of PAHs under anoxic conditions and highlight the mechanistic insights into the metabolic pathways and functional genes. Achievements of practical application and enhancing strategies of anaerobic PAHs bioremediation in soil were summarized. Based on the concerned issues during research, perspectives of further development were proposed including time-consuming enrichment, byproducts with unknown toxicity, and activity inhibition with low temperatures. In addition, meta-omics, synthetic biology and engineering microbiome of developing microbial inoculum for anaerobic bioremediation applications are discussed. We anticipate that integrating the theoretical research on PAHs anaerobic biodegradation and its successful application will advance the development of anaerobic bioremediation.
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Affiliation(s)
- Chao Chen
- College of Life Science, Dalian Minzu University, Dalian, 116600, Liaoning, China; State Key Laboratory of Microbial Metabolism, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Zhan Zhang
- China Tobacco Henan Industrial Co. Ltd., Zhengzhou, 450000, China
| | - Ping Xu
- State Key Laboratory of Microbial Metabolism, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Haiyang Hu
- State Key Laboratory of Microbial Metabolism, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China.
| | - Hongzhi Tang
- State Key Laboratory of Microbial Metabolism, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China.
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11
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Zhang Z, Sun J, Gong X, Yang Z, Wang C, Wang H. Anaerobic phenanthrene biodegradation by a new salt-tolerant/halophilic and nitrate-reducing Virgibacillus halodenitrificans strain PheN4 and metabolic processes exploration. JOURNAL OF HAZARDOUS MATERIALS 2022; 435:129085. [PMID: 35650754 DOI: 10.1016/j.jhazmat.2022.129085] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 05/01/2022] [Accepted: 05/03/2022] [Indexed: 06/15/2023]
Abstract
The biodegradation of polycyclic aromatic hydrocarbons (PAHs) under hypersaline environments has received increasing attention, whereas the study of anaerobic PAH biodegradation under hypersaline environments is still lacking. Here, we found a pure culture designated PheN4, which was affiliated with Virgibacillus halodenitrificans and could degrade phenanthrene with nitrate as the terminal electron acceptor and a wide range of salinities (from 0.3% to 20%) under anaerobic environments. The optimal salinity for biodegradation of phenanthrene by PheN4 was 5%, which could degrade 93.5% of 0.62 ± 0.04 mM phenanthrene within 10 days with the initial inoculum of 0.01 gVSS/L. Meanwhile, an increased microbial amount could efficiently promote the phenanthrene biodegradation rate. The metabolic processes of anaerobic phenanthrene biodegradation under hypersaline conditions by PheN4 were proposed based on intermediates and genome analyses. Phenanthrene was initially activated via methylation to form 2-methylphenanthrene. Next, fumarate addition and β-oxidation or direct oxidation of the methyl group, ring reduction and ring cleavage were identified as the midstream and downstream steps. In addition, PheN4 could utilize benzene, naphthalene, and anthracene as carbon sources, but Benz[a]anthracene, pyrene, and Benzo[a]pyrene could not be biodegraded by PheN4. This study could provide some guidance for the bioremediation of PAH pollutants in anaerobic and hypersaline zones.
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Affiliation(s)
- Zuotao Zhang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Jiao Sun
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Xiaoqiang Gong
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Zhuoyue Yang
- College of Environmental Science & Engineering, Beijing Forestry University, Beijing 100091, China
| | - Chongyang Wang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Hui Wang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
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12
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Roberts GW, Leys D. Structural insights into UbiD reversible decarboxylation. Curr Opin Struct Biol 2022; 75:102432. [PMID: 35843126 DOI: 10.1016/j.sbi.2022.102432] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 06/14/2022] [Accepted: 06/17/2022] [Indexed: 11/03/2022]
Abstract
The ubiquitous UbiX-UbiD system is associated with a wide range of microbial (de)carboxylation reactions. Recent X-ray crystallographic studies have contributed to elucidating the enigmatic mechanism underpinning the conversion of α,β-unsaturated acids by this system. The UbiD component utilises a unique cofactor, prenylated flavin (prFMN), generated by the bespoke action of the associated UbiX flavin prenyltransferase. Structure determination of a range of UbiX/UbiD representatives has revealed a generic mode of action for both the flavin-to-prFMN metamorphosis and the (de)carboxylation. In contrast to the conserved UbiX, the UbiD superfamily is associated with a versatile substrate range. The latter is reflected in the considerable variety of UbiD quaternary structure, dynamic behaviour and active site architecture. Directed evolution of UbiD enzymes has taken advantage of this apparent malleability to generate new variants supporting in vivo hydrocarbon production. Other applications include coupling UbiD to carboxylic acid reductase to convert alkenes into α,β-unsaturated aldehydes via enzymatic CO2 fixation.
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Affiliation(s)
- George W Roberts
- Manchester Institute of Biotechnology, Department of Chemistry, University of Manchester, 131 Princess Street, Manchester, M1 7DN, UK
| | - David Leys
- Manchester Institute of Biotechnology, Department of Chemistry, University of Manchester, 131 Princess Street, Manchester, M1 7DN, UK.
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13
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Bloor S, Michurin I, Titchiner GR, Leys D. Prenylated flavins: structures and mechanisms. FEBS J 2022; 290:2232-2245. [PMID: 35073609 DOI: 10.1111/febs.16371] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 01/05/2022] [Accepted: 01/21/2022] [Indexed: 11/28/2022]
Abstract
The UbiX/UbiD system is widespread in microbes and responsible for the reversible decarboxylation of unsaturated carboxylic acids. The UbiD enzyme catalyzes this unusual reaction using a prenylated flavin (prFMN) as cofactor, the latter formed by the flavin prenyltransferase UbiX. A detailed picture of the biochemistry of flavin prenylation, oxidative maturation, and covalent catalysis underpinning reversible decarboxylation is emerging. This reveals the prFMN cofactor can undergo a wide range of transformations, complemented by considerable UbiD-variability. These provide a blueprint for biotechnological applications aimed at producing hydrocarbons or aromatic C-H activation through carboxylation.
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Affiliation(s)
- Samuel Bloor
- Department of Chemistry, Manchester Institute of Biotechnology, UK
| | | | | | - David Leys
- Department of Chemistry, Manchester Institute of Biotechnology, UK
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14
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Zhang Z, Guo H, Sun J, Gong X, Wang C, Wang H. Anaerobic phenanthrene biodegradation by a newly isolated sulfate-reducer, strain PheS1, and exploration of the biotransformation pathway. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 797:149148. [PMID: 34311378 DOI: 10.1016/j.scitotenv.2021.149148] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Revised: 07/14/2021] [Accepted: 07/15/2021] [Indexed: 06/13/2023]
Abstract
Phenanthrene is a widespread and harmful polycyclic aromatic hydrocarbon that is difficult to anaerobically biodegrade. Current challenges in anaerobic phenanthrene bioremediation are a lack of degrading cultures and limited knowledge of biotransformation pathways. Under sulfate-reducing conditions, pure-cultures and biotransformation processes for anaerobic phenanthrene biodegradation are poorly understood. In this study, strain PheS1, which is phylogenetically closely related to Desulfotomaculum, was found to be a sulfate-reducing phenanthrene-degrading bacterium. Anaerobic phenanthrene biodegradation using PheS1 was proposed based on metabolite and genome analyses, and the initial step was identified as carboxylation based on the detection of 2-phenanthroic acid, [13C]-2-phenanthroic acid, and [D9]-2- phenanthroic acid when phenanthrene+HCO3-, phenanthrene+H13CO3-, and [D10]-phenanthrene+HCO3- were used as the substrate, respectively. PheS1 genome ubiD gene encoding of carboxylase putatively involved in the biodegradation was performed. Next, benzene ring reduction and cleavage that produced benzene compounds and cyclohexane derivative were reported to occur in the downstream biotransformation processes. Additionally, benzene, naphthalene, benz[a]anthracene, and anthracene can be utilised by PheS1, whereas pyrene and benz[a]pyrene cannot. We discovered a new phenanthrene-degrading sulfate-reducer and provided the anaerobic phenanthrene biotransformation pathway under sulfate-reducing conditions, which can act as a reference for practical applications in bioremediation and for studying the molecular mechanisms of phenanthrene in anaerobic zones.
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Affiliation(s)
- Zuotao Zhang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Haijiao Guo
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Jiao Sun
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Xiaoqiang Gong
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Chongyang Wang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Hui Wang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
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15
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Abstract
Aryl coenzyme A (CoA) ligases belong to class I of the adenylate-forming enzyme superfamily (ANL superfamily). They catalyze the formation of thioester bonds between aromatic compounds and CoA and occur in nearly all forms of life. These ligases are involved in various metabolic pathways degrading benzene, toluene, ethylbenzene, and xylene (BTEX) or polycyclic aromatic hydrocarbons (PAHs). They are often necessary to produce the central intermediate benzoyl-CoA that occurs in various anaerobic pathways. The substrate specificity is very diverse between enzymes within the same class, while the dependency on Mg2+, ATP, and CoA as well as oxygen insensitivity are characteristics shared by the whole enzyme class. Some organisms employ the same aryl-CoA ligase when growing aerobically and anaerobically, while others induce different enzymes depending on the environmental conditions. Aryl-CoA ligases can be divided into two major groups, benzoate:CoA ligase-like enzymes and phenylacetate:CoA ligase-like enzymes. They are widely distributed between the phylogenetic clades of the ANL superfamily and show closer relationships within the subfamilies than to other aryl-CoA ligases. This, together with residual CoA ligase activity in various other enzymes of the ANL superfamily, leads to the conclusion that CoA ligases might be the ancestral proteins from which all other ANL superfamily enzymes developed.
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16
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Wang B, Kuang S, Shao H, Wang L, Wang H. Anaerobic-petroleum degrading bacteria: Diversity and biotechnological applications for improving coastal soil. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 224:112646. [PMID: 34399124 DOI: 10.1016/j.ecoenv.2021.112646] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 08/10/2021] [Accepted: 08/11/2021] [Indexed: 06/13/2023]
Abstract
Due to the industrial emissions and accidental spills, the critical material for modern industrial society petroleum pollution causes severe ecological damage. The prosperous oil exploitation and transportation causes the recalcitrant, hazardous, and carcinogenic sludge widespread in the coastal wetlands. The costly physicochemical-based remediation remains the secondary and inadequate treatment for the derivatives along with the tailings. Anaerobic microbial petroleum degrading biotechnology has received extensive attention for its cost acceptable, eco-friendly, and fewer health hazards. As a result of the advances in biotechnology and microbiology, the anaerobic oil-degrading bacteria have been well developing to achieve the same remediation effects with lower operating costs. This review summarizes the advantages and potential scenarios of the anaerobic degrading bacteria, such as sulfate-reducing bacteria, denitrifying bacteria, and metal-reducing bacteria in the coastal area decomposing the alkanes, alkenes, aromatic hydrocarbons, polycyclic aromatic, and related derivatives. In the future, a complete theoretical basis of microbiological biotechnology, molecular biology, and electrochemistry is necessary to make efficient and environmental-friendly use of anaerobic degradation bacteria to mineralize oil sludge organic wastes.
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Affiliation(s)
- Bingchen Wang
- College of Environment and Safety Engineering, Qingdao University of Science and Technology, Qingdao 266042, PR China
| | - Shaoping Kuang
- College of Environment and Safety Engineering, Qingdao University of Science and Technology, Qingdao 266042, PR China.
| | - Hongbo Shao
- College of Environment and Safety Engineering, Qingdao University of Science and Technology, Qingdao 266042, PR China; Institute of Agriculture Resources and Environment, Jiangsu Academy of Agricultural Sciences (JAAS), Nanjing 210014, PR China; Jiangsu Key Laboratory for Bioresources of Saline Soils, Jiangsu Synthetic Innovation Center for Coastal Bio-agriculture, Yancheng Teachers University, Yancheng 224002, China.
| | - Lei Wang
- College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, PR China
| | - Huihui Wang
- College of Polymer Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042, PR China
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17
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Sengupta K, Pal S. A review on microbial diversity and genetic markers involved in methanogenic degradation of hydrocarbons: futuristic prospects of biofuel recovery from contaminated regions. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:40288-40307. [PMID: 33844144 DOI: 10.1007/s11356-021-13666-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 03/23/2021] [Indexed: 06/12/2023]
Abstract
Microbial activities within oil reservoirs have adversely impacted the world's majority of oil by lowering its quality, thereby increasing its recovery and refining cost. Moreover, conventional method of extraction leaves behind nearly two-thirds of the fossil fuels in the oil fields. This huge potential can be extracted if engineered methanogenic consortium is adapted to convert the hydrocarbons into natural gas. This process involves conversion of crude oil hydrocarbons into methanogenic substrates by syntrophic and fermentative bacteria, which are subsequently utilized by methanogens to produce methane. Microbial diversity of such environments supports the viability of this process. This review illuminates the potentials of abundant microbial groups such as Syntrophaceae, Anaerolineaceae, Clostridiales and Euryarchaeota in petroleum hydrocarbon-related environment, their genetic markers, biochemical process and omics-based bioengineering methods involved in methane generation. Increase in the copy numbers of catabolic genes during methanogenesis highlights the prospect of developing engineered biofuel recovery technology. Several lab-based methanogenic consortia from depleted petroleum reservoirs and microcosm studies so far would not be enough for field application without the advent of multi-omics-based technologies to trawl out the bottleneck parameters of the enhanced fuel recovery process. The adaptability of efficient consortium of versatile hydrocarbonoclastic and methanogenic microorganisms under environmental stress conditions is further needed to be investigated. The improved process might hold the potential of methane extraction from petroleum waste like oil tank and refinery sludge, oil field deposits, etc. What sounds as biodegradation could be a beginning of converting waste into wealth by recovery of stranded energy assets.
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Affiliation(s)
- Kriti Sengupta
- Bioenergy Group, Agharkar Research Institute, Pune, 411004, India
| | - Siddhartha Pal
- National Centre for Cell Science, Ganeshkhind, Pune, 411007, India.
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18
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Zhang Z, Sun J, Guo H, Gong X, Wang C, Wang H. Investigation of anaerobic biodegradation of phenanthrene by a sulfate-dependent Geobacter sulfurreducens strain PheS2. JOURNAL OF HAZARDOUS MATERIALS 2021; 409:124522. [PMID: 33229262 DOI: 10.1016/j.jhazmat.2020.124522] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 11/05/2020] [Accepted: 11/06/2020] [Indexed: 06/11/2023]
Abstract
Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous and harmful contaminants, which can be degraded aerobically. However, the persistence of PAHs in anoxic environments indicates that anaerobic biodegradation of PAHs should also be investigated. Pure-culture and biotransformation processes for anaerobic phenanthrene biodegradation with sulfate as a terminal electron acceptor remains in its infancy. In this study, we investigated anaerobic biodegradation of PAHs by PheS2, an isolated phenanthrene-utilizing sulfate-reducer, using phenanthrene as a model compound. PheS2 was phylogenetically closely related to Geobacter sulfurreducens and reduced sulfate to sulfide during anaerobic phenanthrene biodegradation. Phenanthrene biodegradation processes were detected using gas chromatography-mass spectrometry, genome, and reverse transcription quantitative PCR analyses. Carboxylation was the initial step of anaerobic phenanthrene biodegradation based upon detection of 2- and 4-phenanthroic acid, its isotopically labeled analogs when using 13C-labeled bicarbonate and fully deuterated-phenanthrene (C14D10), and genes encoding enzymes putatively involved in the biodegradation. Further, ring-system reducing and cleavage occurred, and substituted benzene series and cyclohexane derivatives were detected in downstream biotransformation metabolites. Additionally, PheS2 can degrade benzene, naphthalene, anthracene, and benz[a]anthracene, but not pyrene and benz[a]pyrene. This study describes the isolation of an anaerobic phenanthrene-degrading sulfate-reducer, the first pure-culture evidence of phenanthrene biotransformation processes with sulfate as an electron acceptor.
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Affiliation(s)
- Zuotao Zhang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Jiao Sun
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Haijiao Guo
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Xiaoqiang Gong
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Chongyang Wang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Hui Wang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
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19
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Qian Y, Xu M, Deng T, Hu W, He Z, Yang X, Wang B, Song D, Chen L, Huang Y, Sun G. Synergistic interactions of Desulfovibrio and Petrimonas for sulfate-reduction coupling polycyclic aromatic hydrocarbon degradation. JOURNAL OF HAZARDOUS MATERIALS 2021; 407:124385. [PMID: 33229269 DOI: 10.1016/j.jhazmat.2020.124385] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Revised: 10/15/2020] [Accepted: 10/23/2020] [Indexed: 06/11/2023]
Abstract
Microbial sulfate-reduction coupling polycyclic aromatic hydrocarbon (PAH) degradation is an important process for the remediation of contaminated sediments. However, little is known about core players and their mechanisms in this process due to the complexity of PAH degradation and the large number of microorganisms involved. Here we analyzed potential core players in a black-odorous sediment using gradient-dilution culturing, isolation and genomic/metagenomic approaches. Along the dilution gradient, microbial PAH degradation and sulfate consumption were not decreased, and even a significant (p = 0.003) increase was observed in the degradation of phenanthrene although the microbial diversity declined. Two species, affiliated with Desulfovibrio and Petrimonas, were commonly present in all of the gradients as keystone taxa and showed as the dominant microorganisms in the single colony (SB8) isolated from the highest dilution culture with 93.49% and 4.73% of the microbial community, respectively. Desulfovibrio sp. SB8 and Petrimonas sp. SB8 could serve together as core players for sulfate-reduction coupling PAH degradation, in which Desulfovibrio sp. SB8 could degrade PAHs to hexahydro-2-naphthoyl through the carboxylation pathway while Petrimonas sp. SB8 might degrade intermediate metabolites of PAHs. This study provides new insights into the microbial sulfate-reduction coupling PAH degradation in black-odorous sediments.
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Affiliation(s)
- Youfen Qian
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China; College of Life Sciences, South China Agricultural University, Guangzhou 510642, China
| | - Meiying Xu
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China.
| | - Tongchu Deng
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
| | - Wenzhe Hu
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
| | - Zhili He
- Environmental Microbiomics Research Center and School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-Sen University, Guangzhou 510006, China
| | - Xunan Yang
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
| | - Bin Wang
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
| | - Da Song
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
| | - Letian Chen
- College of Life Sciences, South China Agricultural University, Guangzhou 510642, China
| | - Youda Huang
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
| | - Guoping Sun
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
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20
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Zhang Z, Guo H, Sun J, Gong X, Wang C, Wang H. Exploration of the biotransformation processes in the biodegradation of phenanthrene by a facultative anaerobe, strain PheF2, with Fe(III) or O 2 as an electron acceptor. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 750:142245. [PMID: 33182168 DOI: 10.1016/j.scitotenv.2020.142245] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 09/01/2020] [Accepted: 09/04/2020] [Indexed: 06/11/2023]
Abstract
The study of biodegradation of polycyclic aromatic hydrocarbons (PAHs) with metal ions as electron acceptors is still in its infancy. Here, a pure culture of PheF2 sharing 99.79% 16S rRNA-sequence similarity with Trichococcus alkaliphilus, which was recently reported to degrade PAHs, was isolated and found to degrade PAHs with Fe (III) or O2 reduction. Phenanthrene was selected as a model of PAH to study the biodegradation process by PheF2 with Fe (III) or O2 as an electron acceptor. PheF2 exhibited nearly 100%, 37.1%, and 28.5% anaerobic biodegradation of phenanthrene at initial concentrations of 280.7 μM, 280.6 μM, and 281.3 μM, respectively, within 10 days under anaerobic conditions with XAD-7 as a carrier, heptamethylnonane (HMN) as a solution, and nothing, respectively. PheF2 could degrade nearly 100% of the initial phenanthrene concentration of 283.4 μM under aerobic conditions within three days. The initial step of phenanthrene biodegradation by PheF2 involved carboxylation and dioxygenation under anaerobic and aerobic conditions, respectively. The biotransformation processes of phenanthrene degradation by PheF2 with Fe(III) or O2 as an electron acceptor were explored by metabolite and genome analysis. These findings provide an important theoretical support for evaluation of PAHs fate and for PAHs pollution control or remediation in anaerobic and aerobic environments.
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Affiliation(s)
- Zuotao Zhang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Haijiao Guo
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Jiao Sun
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Xiaoqiang Gong
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Chongyang Wang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Hui Wang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
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21
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Dong X, Rattray JE, Campbell DC, Webb J, Chakraborty A, Adebayo O, Matthews S, Li C, Fowler M, Morrison NM, MacDonald A, Groves RA, Lewis IA, Wang SH, Mayumi D, Greening C, Hubert CRJ. Thermogenic hydrocarbon biodegradation by diverse depth-stratified microbial populations at a Scotian Basin cold seep. Nat Commun 2020; 11:5825. [PMID: 33203858 PMCID: PMC7673041 DOI: 10.1038/s41467-020-19648-2] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 10/06/2020] [Indexed: 11/08/2022] Open
Abstract
At marine cold seeps, gaseous and liquid hydrocarbons migrate from deep subsurface origins to the sediment-water interface. Cold seep sediments are known to host taxonomically diverse microorganisms, but little is known about their metabolic potential and depth distribution in relation to hydrocarbon and electron acceptor availability. Here we combined geophysical, geochemical, metagenomic and metabolomic measurements to profile microbial activities at a newly discovered cold seep in the deep sea. Metagenomic profiling revealed compositional and functional differentiation between near-surface sediments and deeper subsurface layers. In both sulfate-rich and sulfate-depleted depths, various archaeal and bacterial community members are actively oxidizing thermogenic hydrocarbons anaerobically. Depth distributions of hydrocarbon-oxidizing archaea revealed that they are not necessarily associated with sulfate reduction, which is especially surprising for anaerobic ethane and butane oxidizers. Overall, these findings link subseafloor microbiomes to various biochemical mechanisms for the anaerobic degradation of deeply-sourced thermogenic hydrocarbons.
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Affiliation(s)
- Xiyang Dong
- School of Marine Sciences, Sun Yat-Sen University, Zhuhai, 519082, China.
- Department of Biological Sciences, University of Calgary, Calgary, AB, T2N 1N4, Canada.
| | - Jayne E Rattray
- Department of Biological Sciences, University of Calgary, Calgary, AB, T2N 1N4, Canada
| | - D Calvin Campbell
- Geological Survey of Canada-Atlantic, Dartmouth, NS, B3B 1A6, Canada
| | - Jamie Webb
- Applied Petroleum Technology (Canada), Calgary, AB, T2N 1Z6, Canada
| | - Anirban Chakraborty
- Department of Biological Sciences, University of Calgary, Calgary, AB, T2N 1N4, Canada
| | - Oyeboade Adebayo
- Department of Biological Sciences, University of Calgary, Calgary, AB, T2N 1N4, Canada
| | - Stuart Matthews
- Department of Biological Sciences, University of Calgary, Calgary, AB, T2N 1N4, Canada
| | - Carmen Li
- Department of Biological Sciences, University of Calgary, Calgary, AB, T2N 1N4, Canada
| | - Martin Fowler
- Applied Petroleum Technology (Canada), Calgary, AB, T2N 1Z6, Canada
| | - Natasha M Morrison
- Nova Scotia Department of Energy and Mines, Halifax, NS, B2Y 4A2, Canada
| | - Adam MacDonald
- Nova Scotia Department of Energy and Mines, Halifax, NS, B2Y 4A2, Canada
| | - Ryan A Groves
- Department of Biological Sciences, University of Calgary, Calgary, AB, T2N 1N4, Canada
| | - Ian A Lewis
- Department of Biological Sciences, University of Calgary, Calgary, AB, T2N 1N4, Canada
| | - Scott H Wang
- Department of Biological Sciences, University of Calgary, Calgary, AB, T2N 1N4, Canada
| | - Daisuke Mayumi
- Institute for Geo-Resources and Environment, Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, 305-8567, Japan
| | - Chris Greening
- School of Biological Sciences, Monash University, Clayton, VIC, 3800, Australia
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Casey R J Hubert
- Department of Biological Sciences, University of Calgary, Calgary, AB, T2N 1N4, Canada.
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22
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Laczi K, Erdeiné Kis Á, Szilágyi Á, Bounedjoum N, Bodor A, Vincze GE, Kovács T, Rákhely G, Perei K. New Frontiers of Anaerobic Hydrocarbon Biodegradation in the Multi-Omics Era. Front Microbiol 2020; 11:590049. [PMID: 33304336 PMCID: PMC7701123 DOI: 10.3389/fmicb.2020.590049] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 10/26/2020] [Indexed: 12/17/2022] Open
Abstract
The accumulation of petroleum hydrocarbons in the environment substantially endangers terrestrial and aquatic ecosystems. Many microbial strains have been recognized to utilize aliphatic and aromatic hydrocarbons under aerobic conditions. Nevertheless, most of these pollutants are transferred by natural processes, including rain, into the underground anaerobic zones where their degradation is much more problematic. In oxic zones, anaerobic microenvironments can be formed as a consequence of the intensive respiratory activities of (facultative) aerobic microbes. Even though aerobic bioremediation has been well-characterized over the past few decades, ample research is yet to be done in the field of anaerobic hydrocarbon biodegradation. With the emergence of high-throughput techniques, known as omics (e.g., genomics and metagenomics), the individual biodegraders, hydrocarbon-degrading microbial communities and metabolic pathways, interactions can be described at a contaminated site. Omics approaches provide the opportunity to examine single microorganisms or microbial communities at the system level and elucidate the metabolic networks, interspecies interactions during hydrocarbon mineralization. Metatranscriptomics and metaproteomics, for example, can shed light on the active genes and proteins and functional importance of the less abundant species. Moreover, novel unculturable hydrocarbon-degrading strains and enzymes can be discovered and fit into the metabolic networks of the community. Our objective is to review the anaerobic hydrocarbon biodegradation processes, the most important hydrocarbon degraders and their diverse metabolic pathways, including the use of various terminal electron acceptors and various electron transfer processes. The review primarily focuses on the achievements obtained by the current high-throughput (multi-omics) techniques which opened new perspectives in understanding the processes at the system level including the metabolic routes of individual strains, metabolic/electric interaction of the members of microbial communities. Based on the multi-omics techniques, novel metabolic blocks can be designed and used for the construction of microbial strains/consortia for efficient removal of hydrocarbons in anaerobic zones.
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Affiliation(s)
- Krisztián Laczi
- Department of Biotechnology, University of Szeged, Szeged, Hungary
| | - Ágnes Erdeiné Kis
- Department of Biotechnology, University of Szeged, Szeged, Hungary.,Institute of Biophysics, Biological Research Centre, Szeged, Hungary
| | - Árpád Szilágyi
- Department of Biotechnology, University of Szeged, Szeged, Hungary
| | - Naila Bounedjoum
- Department of Biotechnology, University of Szeged, Szeged, Hungary.,Institute of Environmental and Technological Sciences, University of Szeged, Szeged, Hungary
| | - Attila Bodor
- Department of Biotechnology, University of Szeged, Szeged, Hungary.,Institute of Biophysics, Biological Research Centre, Szeged, Hungary.,Institute of Environmental and Technological Sciences, University of Szeged, Szeged, Hungary
| | | | - Tamás Kovács
- Department of Biotechnology, Nanophagetherapy Center, Enviroinvest Corporation, Pécs, Hungary
| | - Gábor Rákhely
- Department of Biotechnology, University of Szeged, Szeged, Hungary.,Institute of Biophysics, Biological Research Centre, Szeged, Hungary.,Institute of Environmental and Technological Sciences, University of Szeged, Szeged, Hungary
| | - Katalin Perei
- Department of Biotechnology, University of Szeged, Szeged, Hungary.,Institute of Environmental and Technological Sciences, University of Szeged, Szeged, Hungary
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23
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Zhang Z, Sun J, Guo H, Wang C, Fang T, Rogers MJ, He J, Wang H. Anaerobic biodegradation of phenanthrene by a newly isolated nitrate-dependent Achromobacter denitrificans strain PheN1 and exploration of the biotransformation processes by metabolite and genome analyses. Environ Microbiol 2020; 23:908-923. [PMID: 32812321 DOI: 10.1111/1462-2920.15201] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 08/15/2020] [Indexed: 11/29/2022]
Abstract
Polycyclic aromatic hydrocarbons (PAHs) are widespread and harmful contaminants and are more persistent under anaerobic conditions. The bioremediation of PAHs in anaerobic zones has been enhanced by treating the contamination with nitrate, which is thermodynamically favourable, cost-effective, and highly soluble. However, anaerobic PAHs biotransformation processes that employ nitrate as an electron acceptor have not been fully explored. In this study, we investigated the anaerobic biotransformation of PAHs by strain PheN1, a newly isolated phenanthrene-degrading denitrifier, using phenanthrene as a model compound. PheN1 is phylogenetically closely related to Achromobacter denitrificans and reduces nitrate to nitrite (not N2 ) during the anaerobic phenanthrene degradation process. Phenanthrene biotransformation processes were detected using gas chromatography-mass spectrometry and were further examined by reverse transcription-quantitative PCR and genome analyses. Carboxylation and methylation were both found to be the initial steps in the phenanthrene degradation process. Downstream biotransformation processed benzene compounds and cyclohexane derivatives. This study describes the isolation of an anaerobic phenanthrene-degrading bacterium along with the pure-culture evidence of phenanthrene biotransformation processes with nitrate as an electron acceptor. The findings in this study can improve our understanding of anaerobic PAHs biodegradation processes and guide PAHs bioremediation by adding nitrate to anaerobic environments.
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Affiliation(s)
- Zuotao Zhang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, China
| | - Jiao Sun
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, China
| | - Haijiao Guo
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, China
| | - Chongyang Wang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, China
| | - Tingting Fang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, China
| | - Matthew J Rogers
- Department of Civil and Environmental Engineering, National University of Singapore, Singapore
| | - Jianzhong He
- Department of Civil and Environmental Engineering, National University of Singapore, Singapore
| | - Hui Wang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, China
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24
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Chen G, Widdel F, Musat F. Effect of energy deprivation on metabolite release by anaerobic marine naphthalene‐degrading sulfate‐reducing bacteria. Environ Microbiol 2020; 22:4057-4066. [DOI: 10.1111/1462-2920.15195] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 08/02/2020] [Accepted: 08/09/2020] [Indexed: 01/18/2023]
Affiliation(s)
- Gao Chen
- Max Planck Institute for Marine Microbiology Celsiusstraße 1 Bremen D‐28359 Germany
- Department of Civil and Environmental Engineering University of Tennessee Knoxville, TN 37996 USA
| | - Friedrich Widdel
- Max Planck Institute for Marine Microbiology Celsiusstraße 1 Bremen D‐28359 Germany
| | - Florin Musat
- Max Planck Institute for Marine Microbiology Celsiusstraße 1 Bremen D‐28359 Germany
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research – UFZ, Permoserstr., 15, 04318 Leipzig Germany
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25
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Uzun M, Alekseeva L, Krutkina M, Koziaeva V, Grouzdev D. Unravelling the diversity of magnetotactic bacteria through analysis of open genomic databases. Sci Data 2020; 7:252. [PMID: 32737307 PMCID: PMC7449369 DOI: 10.1038/s41597-020-00593-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 07/03/2020] [Indexed: 11/17/2022] Open
Abstract
Magnetotactic bacteria (MTB) are prokaryotes that possess genes for the synthesis of membrane-bounded crystals of magnetite or greigite, called magnetosomes. Despite over half a century of studying MTB, only about 60 genomes have been sequenced. Most belong to Proteobacteria, with a minority affiliated with the Nitrospirae, Omnitrophica, Planctomycetes, and Latescibacteria. Due to the scanty information available regarding MTB phylogenetic diversity, little is known about their ecology, evolution and about the magnetosome biomineralization process. This study presents a large-scale search of magnetosome biomineralization genes and reveals 38 new MTB genomes. Several of these genomes were detected in the phyla Elusimicrobia, Candidatus Hydrogenedentes, and Nitrospinae, where magnetotactic representatives have not previously been reported. Analysis of the obtained putative magnetosome biomineralization genes revealed a monophyletic origin capable of putative greigite magnetosome synthesis. The ecological distributions of the reconstructed MTB genomes were also analyzed and several patterns were identified. These data suggest that open databases are an excellent source for obtaining new information of interest.
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Affiliation(s)
- Maria Uzun
- Research Center of Biotechnology of the Russian Academy of Sciences, Institute of Bioengineering, Moscow, Russia. .,Lomonosov Moscow State University, Moscow, Russia.
| | - Lolita Alekseeva
- Research Center of Biotechnology of the Russian Academy of Sciences, Institute of Bioengineering, Moscow, Russia.,Lomonosov Moscow State University, Moscow, Russia
| | - Maria Krutkina
- Research Center of Biotechnology of the Russian Academy of Sciences, Institute of Bioengineering, Moscow, Russia
| | - Veronika Koziaeva
- Research Center of Biotechnology of the Russian Academy of Sciences, Institute of Bioengineering, Moscow, Russia
| | - Denis Grouzdev
- Research Center of Biotechnology of the Russian Academy of Sciences, Institute of Bioengineering, Moscow, Russia
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26
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Weyrauch P, Heker I, Zaytsev AV, von Hagen CA, Arnold ME, Golding BT, Meckenstock RU. The 5,6,7,8-Tetrahydro-2-Naphthoyl-Coenzyme A Reductase Reaction in the Anaerobic Degradation of Naphthalene and Identification of Downstream Metabolites. Appl Environ Microbiol 2020; 86:e00996-20. [PMID: 32444470 PMCID: PMC7376553 DOI: 10.1128/aem.00996-20] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 05/15/2020] [Indexed: 11/20/2022] Open
Abstract
Anaerobic degradation of polycyclic aromatic hydrocarbons has been investigated mostly with naphthalene as a model compound. Naphthalene degradation by sulfate-reducing bacteria proceeds via carboxylation to 2-naphthoic acid, formation of a coenzyme A thioester, and subsequent reduction to 5,6,7,8-tetrahydro-2-naphthoyl-coenzyme A (THNCoA), which is further reduced to hexahydro-2-naphthoyl-CoA (HHNCoA) by tetrahydronaphthoyl-CoA reductase (THNCoA reductase), an enzyme similar to class I benzoyl-CoA reductases. When analyzing THNCoA reductase assays with crude cell extracts and NADH as electron donor via liquid chromatography-mass spectrometry (LC-MS), scanning for putative metabolites, we found that small amounts of the product of an HHNCoA hydratase were formed in the assays, but the downstream conversion by an NAD+-dependent β-hydroxyacyl-CoA dehydrogenase was prevented by the excess of NADH in those assays. Experiments with alternative electron donors indicated that 2-oxoglutarate can serve as an indirect electron donor for the THNCoA-reducing system via a 2-oxoglutarate:ferredoxin oxidoreductase. With 2-oxoglutarate as electron donor, THNCoA was completely converted and further metabolites resulting from subsequent β-oxidation-like reactions and hydrolytic ring cleavage were detected. These metabolites indicate a downstream pathway with water addition to HHNCoA and ring fission via a hydrolase acting on a β'-hydroxy-β-oxo-decahydro-2-naphthoyl-CoA intermediate. Formation of the downstream intermediate cis-2-carboxycyclohexylacetyl-CoA, which is the substrate for the previously described lower degradation pathway leading to the central metabolism, completes the anaerobic degradation pathway of naphthalene.IMPORTANCE Anaerobic degradation of polycyclic aromatic hydrocarbons is poorly investigated despite its significance in anoxic sediments. Using alternative electron donors for the 5,6,7,8-tetrahydro-2-naphthoyl-CoA reductase reaction, we observed intermediary metabolites of anaerobic naphthalene degradation via in vitro enzyme assays with cell extracts of anaerobic naphthalene degraders. The identified metabolites provide evidence that ring reduction terminates at the stage of hexahydro-2-naphthoyl-CoA and a sequence of β-oxidation-like degradation reactions starts with a hydratase acting on this intermediate. The final product of this reaction sequence was identified as cis-2-carboxycyclohexylacetyl-CoA, a compound for which a further downstream degradation pathway has recently been published (P. Weyrauch, A. V. Zaytsev, S. Stephan, L. Kocks, et al., Environ Microbiol 19:2819-2830, 2017, https://doi.org/10.1111/1462-2920.13806). Our study reveals the first ring-cleaving reaction in the anaerobic naphthalene degradation pathway. It closes the gap between the reduction of the first ring of 2-naphthoyl-CoA by 2-napthoyl-CoA reductase and the lower degradation pathway starting from cis-2-carboxycyclohexylacetyl-CoA, where the second ring cleavage takes place.
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Affiliation(s)
- Philip Weyrauch
- Biofilm Centre, University of Duisburg-Essen, Essen, Germany
- Institute of Groundwater Ecology, Helmholtz Zentrum München, Neuherberg, Germany
| | - Isabelle Heker
- Biofilm Centre, University of Duisburg-Essen, Essen, Germany
| | - Andrey V Zaytsev
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | | | - Meike E Arnold
- Biofilm Centre, University of Duisburg-Essen, Essen, Germany
| | - Bernard T Golding
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
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27
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Atashgahi S. Discovered by genomics: putative reductive dehalogenases with N-terminus transmembrane helixes. FEMS Microbiol Ecol 2020; 95:5426821. [PMID: 30942854 PMCID: PMC6797604 DOI: 10.1093/femsec/fiz048] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 04/02/2019] [Indexed: 11/13/2022] Open
Abstract
Attempts for bioremediation of toxic organohalogens resulted in the identification of organohalide-respiring bacteria harbouring reductive dehalogenases (RDases) enzymes. RDases consist of the catalytic subunit (RdhA, encoded by rdhA) that does not have membrane-integral domains, and a small putative membrane anchor (RdhB, encoded by rdhB) that (presumably) locates the A subunit to the outside of the cytoplasmic membrane. Recent genomic studies identified a putative rdh gene in an uncultured deltaproteobacterial genome that was not accompanied by an rdhB gene, but contained transmembrane helixes in N-terminus. Therefore, rather than having a separate membrane anchor protein, this putative RDase is likely a hybrid of RdhA and RdhB, and directly connected to the membrane with transmembrane helixes. However, functionality of the hybrid putative RDase remains unknown. Further analysis showed that the hybrid putative rdh genes are present in the genomes of pure cultures and uncultured members of Bacteriodetes and Deltaproteobacteria, but also in the genomes of the candidate divisions. The encoded hybrid putative RDases have cytoplasmic or exoplasmic C-terminus localization, and cluster phylogenetically separately from the existing RDase groups. With increasing availability of (meta)genomes, more diverse and likely novel rdh genes are expected, but questions regarding their functionality and ecological roles remain open.
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Affiliation(s)
- Siavash Atashgahi
- Laboratory of Microbiology, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands.,Department of Microbiology, IWWR, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands.,Soehngen Institute of Anaerobic Microbiology, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
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28
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Dhar K, Subashchandrabose SR, Venkateswarlu K, Krishnan K, Megharaj M. Anaerobic Microbial Degradation of Polycyclic Aromatic Hydrocarbons: A Comprehensive Review. REVIEWS OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2020; 251:25-108. [PMID: 31011832 DOI: 10.1007/398_2019_29] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Polycyclic aromatic hydrocarbons (PAHs) are a class of hazardous organic contaminants that are widely distributed in nature, and many of them are potentially toxic to humans and other living organisms. Biodegradation is the major route of detoxification and removal of PAHs from the environment. Aerobic biodegradation of PAHs has been the subject of extensive research; however, reports on anaerobic biodegradation of PAHs are so far limited. Microbial degradation of PAHs under anaerobic conditions is difficult because of the slow growth rate of anaerobes and low energy yield in the metabolic processes. Despite the limitations, some anaerobic bacteria degrade PAHs under nitrate-reducing, sulfate-reducing, iron-reducing, and methanogenic conditions. Anaerobic biodegradation, though relatively slow, is a significant process of natural attenuation of PAHs from the impacted anoxic environments such as sediments, subsurface soils, and aquifers. This review is intended to provide comprehensive details on microbial degradation of PAHs under various reducing conditions, to describe the degradation mechanisms, and to identify the areas that should receive due attention in further investigations.
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Affiliation(s)
- Kartik Dhar
- Global Centre for Environmental Remediation (GCER), Faculty of Science, The University of Newcastle, Callaghan, NSW, Australia
- Department of Microbiology, University of Chittagong, Chittagong, Bangladesh
| | - Suresh R Subashchandrabose
- Global Centre for Environmental Remediation (GCER), Faculty of Science, The University of Newcastle, Callaghan, NSW, Australia
| | - Kadiyala Venkateswarlu
- Formerly Department of Microbiology, Sri Krishnadevaraya University, Anantapuramu, India
| | - Kannan Krishnan
- Global Centre for Environmental Remediation (GCER), Faculty of Science, The University of Newcastle, Callaghan, NSW, Australia
| | - Mallavarapu Megharaj
- Global Centre for Environmental Remediation (GCER), Faculty of Science, The University of Newcastle, Callaghan, NSW, Australia.
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29
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Geiger RA, Junghare M, Mergelsberg M, Ebenau‐Jehle C, Jesenofsky VJ, Jehmlich N, von Bergen M, Schink B, Boll M. Enzymes involved in phthalate degradation in sulphate‐reducing bacteria. Environ Microbiol 2019; 21:3601-3612. [DOI: 10.1111/1462-2920.14681] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 05/03/2019] [Accepted: 05/11/2019] [Indexed: 12/31/2022]
Affiliation(s)
| | - Madan Junghare
- Department of Biology, Microbial EcologyUniversity of Konstanz, 78457 Constance Germany
| | - Mario Mergelsberg
- Faculty of Biology–MicrobiologyUniversity of Freiburg, 79104 Freiburg Germany
| | | | | | - Nico Jehmlich
- Department of Molecular Systems BiologyHelmholtz Centre for Environmental Research UFZ 04318 Leipzig Germany
| | - Martin von Bergen
- Department of Molecular Systems BiologyHelmholtz Centre for Environmental Research UFZ 04318 Leipzig Germany
- Institute of Biochemistry, Faculty of Life SciencesUniversity of Leipzig Brüderstr. 34, 04103 Leipzig Germany
| | - Bernhard Schink
- Department of Biology, Microbial EcologyUniversity of Konstanz, 78457 Constance Germany
| | - Matthias Boll
- Faculty of Biology–MicrobiologyUniversity of Freiburg, 79104 Freiburg Germany
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30
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Kraiselburd I, Brüls T, Heilmann G, Kaschani F, Kaiser M, Meckenstock RU. Metabolic reconstruction of the genome of candidate Desulfatiglans TRIP_1 and identification of key candidate enzymes for anaerobic phenanthrene degradation. Environ Microbiol 2019; 21:1267-1286. [PMID: 30680888 PMCID: PMC6849830 DOI: 10.1111/1462-2920.14527] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 12/12/2018] [Indexed: 11/30/2022]
Abstract
Polycyclic aromatic hydrocarbons (PAHs) are widely distributed pollutants. As oxygen is rapidly depleted in water‐saturated PAH‐contaminated sites, anaerobic microorganisms are crucial for their consumption. Here, we report the metabolic pathway for anaerobic degradation of phenanthrene by a sulfate‐reducing enrichment culture (TRIP) obtained from a natural asphalt lake. The dominant organism of this culture belongs to the Desulfobacteraceae family of Deltaproteobacteria and genome‐resolved metagenomics led to the reconstruction of its genome along with a handful of genomes from lower abundance bacteria. Proteogenomic analyses confirmed metabolic capabilities for dissimilatory sulfate reduction and indicated the presence of the Embden‐Meyerhof‐Parnas pathway, a complete tricarboxylic acid cycle as well as a complete Wood‐Ljungdahl pathway. Genes encoding enzymes putatively involved in the degradation of phenanthrene were identified. This includes two gene clusters encoding a multisubunit carboxylase complex likely involved in the activation of phenanthrene, as well as genes encoding reductases potentially involved in subsequent ring dearomatization and reduction steps. The predicted metabolic pathways were corroborated by transcriptome and proteome analyses, and provide the first insights into the metabolic pathway responsible for the anaerobic degradation of three‐ringed PAHs.
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Affiliation(s)
- Ivana Kraiselburd
- Biofilm Centre, Aquatic Microbiology Department, Faculty of Chemistry, University Duisburg-Essen, Essen, Germany
| | - Thomas Brüls
- CEA, DRF, Institut Jacob, Genoscope, Evry, France.,CNRS-UMR8030, Université Paris-Saclay, Evry, France
| | - Geronimo Heilmann
- Centre of Medical Biotechnology, Chemical Biology Department, Faculty of Biology, University Duisburg-Essen, Essen, Germany
| | - Farnusch Kaschani
- Centre of Medical Biotechnology, Chemical Biology Department, Faculty of Biology, University Duisburg-Essen, Essen, Germany
| | - Markus Kaiser
- Centre of Medical Biotechnology, Chemical Biology Department, Faculty of Biology, University Duisburg-Essen, Essen, Germany
| | - Rainer U Meckenstock
- Biofilm Centre, Aquatic Microbiology Department, Faculty of Chemistry, University Duisburg-Essen, Essen, Germany
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31
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Shin B, Kim M, Zengler K, Chin KJ, Overholt WA, Gieg LM, Konstantinidis KT, Kostka JE. Anaerobic degradation of hexadecane and phenanthrene coupled to sulfate reduction by enriched consortia from northern Gulf of Mexico seafloor sediment. Sci Rep 2019; 9:1239. [PMID: 30718896 PMCID: PMC6361983 DOI: 10.1038/s41598-018-36567-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 11/12/2018] [Indexed: 11/16/2022] Open
Abstract
To advance understanding of the fate of hydrocarbons released from the Deepwater Horizon oil spill and deposited in marine sediments, this study characterized the microbial populations capable of anaerobic hydrocarbon degradation coupled with sulfate reduction in non-seep sediments of the northern Gulf of Mexico. Anaerobic, sediment-free enrichment cultures were obtained with either hexadecane or phenanthrene as sole carbon source and sulfate as a terminal electron acceptor. Phylogenetic analysis revealed that enriched microbial populations differed by hydrocarbon substrate, with abundant SSU rRNA gene amplicon sequences from hexadecane cultures showing high sequence identity (up to 98%) to Desulfatibacillum alkenivorans (family Desulfobacteraceae), while phenanthrene-enriched populations were most closely related to Desulfatiglans spp. (up to 95% sequence identity; family Desulfarculaceae). Assuming complete oxidation to CO2, observed stoichiometric ratios closely resembled the theoretical ratios of 12.25:1 for hexadecane and 8.25:1 for phenanthrene degradation coupled to sulfate reduction. Phenanthrene carboxylic acid was detected in the phenanthrene-degrading enrichment cultures, providing evidence to indicate carboxylation as an activation mechanism for phenanthrene degradation. Metagenome-assembled genomes (MAGs) revealed that phenanthrene degradation is likely mediated by novel genera or families of sulfate-reducing bacteria along with their fermentative syntrophic partners, and candidate genes linked to the degradation of aromatic hydrocarbons were detected for future study.
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Affiliation(s)
- Boryoung Shin
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, 30332, USA
| | - Minjae Kim
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, 30332, USA
| | - Karsten Zengler
- Department of Pediatrics, University of California, San Diego, 92093, USA
- Center for Microbiome Innovation, University of California, San Diego, 92093, USA
| | - Kuk-Jeong Chin
- Department of Biology, Georgia State University, Atlanta, 30302, USA
| | - Will A Overholt
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, 30332, USA
| | - Lisa M Gieg
- Department of Biological Sciences, University of Calgary, Calgary, T2N 1N4, Canada
| | - Konstantinos T Konstantinidis
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, 30332, USA
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, 30332, USA
| | - Joel E Kostka
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, 30332, USA.
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, 30332, USA.
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32
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Jochum LM, Schreiber L, Marshall IPG, Jørgensen BB, Schramm A, Kjeldsen KU. Single-Cell Genomics Reveals a Diverse Metabolic Potential of Uncultivated Desulfatiglans-Related Deltaproteobacteria Widely Distributed in Marine Sediment. Front Microbiol 2018; 9:2038. [PMID: 30233524 PMCID: PMC6129605 DOI: 10.3389/fmicb.2018.02038] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 08/13/2018] [Indexed: 11/13/2022] Open
Abstract
Desulfatiglans-related organisms comprise one of the most abundant deltaproteobacterial lineages in marine sediments where they occur throughout the sediment column in a gradient of increasing sulfate and organic carbon limitation with depth. Characterized Desulfatiglans isolates are dissimilatory sulfate reducers able to grow by degrading aromatic hydrocarbons. The ecophysiology of environmental Desulfatiglans-populations is poorly understood, however, possibly utilization of aromatic compounds may explain their predominance in marine subsurface sediments. We sequenced and analyzed seven Desulfatiglans-related single-cell genomes (SAGs) from Aarhus Bay sediments to characterize their metabolic potential with regard to aromatic compound degradation and energy metabolism. The average genome assembly size was 1.3 Mbp and completeness estimates ranged between 20 and 50%. Five of the SAGs (group 1) originated from the sulfate-rich surface part of the sediment while two (group 2) originated from sulfate-depleted subsurface sediment. Based on 16S rRNA gene amplicon sequencing group 2 SAGs represent the more frequent types of Desulfatiglans-populations in Aarhus Bay sediments. Genes indicative of aromatic compound degradation could be identified in both groups, but the two groups were metabolically distinct with regard to energy conservation. Group 1 SAGs carry a full set of genes for dissimilatory sulfate reduction, whereas the group 2 SAGs lacked any genetic evidence for sulfate reduction. The latter may be due to incompleteness of the SAGs, but as alternative energy metabolisms group 2 SAGs carry the genetic potential for growth by acetogenesis and fermentation. Group 1 SAGs encoded reductive dehalogenase genes, allowing them to access organohalides and possibly conserve energy by their reduction. Both groups possess sulfatases unlike their cultured relatives allowing them to utilize sulfate esters as source of organic carbon and sulfate. In conclusion, the uncultivated marine Desulfatiglans populations are metabolically diverse, likely reflecting different strategies for coping with energy and sulfate limitation in the subsurface seabed.
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Affiliation(s)
- Lara M Jochum
- Center for Geomicrobiology, Section for Microbiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Lars Schreiber
- Center for Geomicrobiology, Section for Microbiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Ian P G Marshall
- Center for Geomicrobiology, Section for Microbiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Bo B Jørgensen
- Center for Geomicrobiology, Section for Microbiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Andreas Schramm
- Center for Geomicrobiology, Section for Microbiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Kasper U Kjeldsen
- Center for Geomicrobiology, Section for Microbiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
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Qian HX, Liao RZ. QM/MM Study of Tungsten-Dependent Benzoyl-Coenzyme A Reductase: Rationalization of Regioselectivity and Predication of W vs Mo Selectivity. Inorg Chem 2018; 57:10667-10678. [DOI: 10.1021/acs.inorgchem.8b01328] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Hui-Xia Qian
- Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica, Hubei Key Laboratory of Materials Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Rong-Zhen Liao
- Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica, Hubei Key Laboratory of Materials Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
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Stable Isotope and Metagenomic Profiling of a Methanogenic Naphthalene-Degrading Enrichment Culture. Microorganisms 2018; 6:microorganisms6030065. [PMID: 29996505 PMCID: PMC6164631 DOI: 10.3390/microorganisms6030065] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 07/02/2018] [Accepted: 07/08/2018] [Indexed: 11/23/2022] Open
Abstract
Polycyclic aromatic hydrocarbons (PAH) such as naphthalene are widespread, recalcitrant pollutants in anoxic and methanogenic environments. A mechanism catalyzing PAH activation under methanogenic conditions has yet to be discovered, and the microbial communities coordinating their metabolism are largely unknown. This is primarily due to the difficulty of cultivating PAH degraders, requiring lengthy incubations to yield sufficient biomass for biochemical analysis. Here, we sought to characterize a new methanogenic naphthalene-degrading enrichment culture using DNA-based stable isotope probing (SIP) and metagenomic analyses. 16S rRNA gene sequencing of fractionated DNA pinpointed an unclassified Clostridiaceae species as a putative naphthalene degrader after two months of SIP incubation. This finding was supported by metabolite and metagenomic evidence of genes predicted to encode for enzymes facilitating naphthalene carboxylic acid CoA-thioesterification and degradation of an unknown arylcarboxyl-CoA structure. Our findings also suggest a possible but unknown role for Desulfuromonadales in naphthalene degradation. This is the first reported functional evidence of PAH biodegradation by a methanogenic consortium, and we envision that this approach could be used to assess carbon flow through other slow growing enrichment cultures and environmental samples.
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Wolfson SJ, Porter AW, Kerkhof LJ, McGuinness LM, Prince RC, Young LY. Sulfate-Reducing Naphthalene Degraders Are Picky Eaters. Microorganisms 2018; 6:microorganisms6030059. [PMID: 29941798 PMCID: PMC6163709 DOI: 10.3390/microorganisms6030059] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 06/18/2018] [Accepted: 06/21/2018] [Indexed: 11/27/2022] Open
Abstract
Polycyclic aromatic hydrocarbons (PAHs) are common organic contaminants found in anoxic environments. The capacity for PAH biodegradation in unimpacted environments, however, has been understudied. Here we investigate the enrichment, selection, and sustainability of a microbial community from a pristine environment on naphthalene as the only amended carbon source. Pristine coastal sediments were obtained from the Jacques Cousteau National Estuarine Research Reserve in Tuckerton, New Jersey, an ecological reserve which has no direct input or source of hydrocarbons. After an initial exposure to naphthalene, primary anaerobic transfer cultures completely degraded 500 µM naphthalene within 139 days. Subsequent transfer cultures mineralized naphthalene within 21 days with stoichiometric sulfate loss. Enriched cultures efficiently utilized only naphthalene and 2-methylnaphthalene from the hydrocarbon mixtures in crude oil. To determine the microorganisms responsible for naphthalene degradation, stable isotope probing was utilized on cultures amended with fully labeled 13C-naphthalene as substrate. Three organisms were found to unambiguously synthesize 13C-DNA from 13C-naphthalene within 7 days. Phylogenetic analysis revealed that 16S rRNA genes from two of these organisms are closely related to the known naphthalene degrading isolates NaphS2 and NaphS3 from PAH-contaminated sites. A third 16S rRNA gene was only distantly related to its closest relative and may represent a novel naphthalene degrading microbe from this environment.
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Affiliation(s)
- Sarah J Wolfson
- Department of Environmental Sciences, Rutgers University, New Brunswick, NJ 08901, USA.
| | - Abigail W Porter
- Department of Environmental Sciences, Rutgers University, New Brunswick, NJ 08901, USA.
| | - Lee J Kerkhof
- Department of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ 08901, USA.
| | - Lora M McGuinness
- Department of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ 08901, USA.
| | | | - Lily Y Young
- Department of Environmental Sciences, Rutgers University, New Brunswick, NJ 08901, USA.
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Metagenomics Reveals the Influence of Land Use and Rain on the Benthic Microbial Communities in a Tropical Urban Waterway. mSystems 2018; 3:mSystems00136-17. [PMID: 29896568 PMCID: PMC5989131 DOI: 10.1128/msystems.00136-17] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 05/06/2018] [Indexed: 11/29/2022] Open
Abstract
Unravelling the microbial metagenomes of urban waterway sediments suggest that well-managed urban waterways have the potential to support diverse sedimentary microbial communities, similar to those of undisturbed natural freshwaters. Despite the fact that these urban waterways are well managed, our study shows that environmental pressures from land use and rain perturbations play a role in shaping the structure and functions of microbial communities in these waterways. We propose that although pulsed disturbances, such as rain perturbations, influence microbial communities, press disturbances, including land usage history, have a long-term and stronger influence on microbial communities. Our study found that the functions of microbial communities were less affected by environmental factors than the structure of microbial communities was, indicating that core microbial functions largely remain conserved in challenging environments. Growing demands for potable water have led to extensive reliance on waterways in tropical megacities. Attempts to manage these waterways in an environmentally sustainable way generally lack an understanding of microbial processes and how they are influenced by urban factors, such as land use and rain. Here, we describe the composition and functional potential of benthic microbial communities from an urban waterway network and analyze the effects of land use and rain perturbations on these communities. With a sequence depth of 3 billion reads from 48 samples, these metagenomes represent nearly full coverage of microbial communities. The predominant taxa in these waterways were Nitrospira and Coleofasciculus, indicating the presence of nitrogen and carbon fixation in this system. Gene functions from carbohydrate, protein, and nucleic acid metabolism suggest the presence of primary and secondary productivity in such nutrient-deficient systems. Comparison of microbial communities by land use type and rain showed that while there are significant differences in microbial communities in land use, differences due to rain perturbations were rain event specific. The more diverse microbial communities in the residential areas featured a higher abundance of reads assigned to genes related to community competition. However, the less diverse communities from industrial areas showed a higher abundance of reads assigned to specialized functions such as organic remediation. Finally, our study demonstrates that microbially diverse populations in well-managed waterways, where contaminant levels are within defined limits, are comparable to those in other relatively undisturbed freshwater systems. IMPORTANCE Unravelling the microbial metagenomes of urban waterway sediments suggest that well-managed urban waterways have the potential to support diverse sedimentary microbial communities, similar to those of undisturbed natural freshwaters. Despite the fact that these urban waterways are well managed, our study shows that environmental pressures from land use and rain perturbations play a role in shaping the structure and functions of microbial communities in these waterways. We propose that although pulsed disturbances, such as rain perturbations, influence microbial communities, press disturbances, including land usage history, have a long-term and stronger influence on microbial communities. Our study found that the functions of microbial communities were less affected by environmental factors than the structure of microbial communities was, indicating that core microbial functions largely remain conserved in challenging environments.
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A benzene-degrading nitrate-reducing microbial consortium displays aerobic and anaerobic benzene degradation pathways. Sci Rep 2018. [PMID: 29540736 PMCID: PMC5852087 DOI: 10.1038/s41598-018-22617-x] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
In this study, we report transcription of genes involved in aerobic and anaerobic benzene degradation pathways in a benzene-degrading denitrifying continuous culture. Transcripts associated with the family Peptococcaceae dominated all samples (21-36% relative abundance) indicating their key role in the community. We found a highly transcribed gene cluster encoding a presumed anaerobic benzene carboxylase (AbcA and AbcD) and a benzoate-coenzyme A ligase (BzlA). Predicted gene products showed >96% amino acid identity and similar gene order to the corresponding benzene degradation gene cluster described previously, providing further evidence for anaerobic benzene activation via carboxylation. For subsequent benzoyl-CoA dearomatization, bam-like genes analogous to the ones found in other strict anaerobes were transcribed, whereas gene transcripts involved in downstream benzoyl-CoA degradation were mostly analogous to the ones described in facultative anaerobes. The concurrent transcription of genes encoding enzymes involved in oxygenase-mediated aerobic benzene degradation suggested oxygen presence in the culture, possibly formed via a recently identified nitric oxide dismutase (Nod). Although we were unable to detect transcription of Nod-encoding genes, addition of nitrite and formate to the continuous culture showed indication for oxygen production. Such an oxygen production would enable aerobic microbes to thrive in oxygen-depleted and nitrate-containing subsurface environments contaminated with hydrocarbons.
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The UbiX-UbiD system: The biosynthesis and use of prenylated flavin (prFMN). Arch Biochem Biophys 2017; 632:209-221. [DOI: 10.1016/j.abb.2017.07.014] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 07/19/2017] [Accepted: 07/24/2017] [Indexed: 12/17/2022]
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Huang H, Tao X, Jiang Y, Khan A, Wu Q, Yu X, Wu D, Chen Y, Ling Z, Liu P, Li X. The naphthalene catabolic protein NahG plays a key role in hexavalent chromium reduction in Pseudomonas brassicacearum LZ-4. Sci Rep 2017; 7:9670. [PMID: 28852154 PMCID: PMC5575117 DOI: 10.1038/s41598-017-10469-w] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 08/10/2017] [Indexed: 11/09/2022] Open
Abstract
Soil contamination by PAH and heavy metals is a growing problem. Here, we showed that a new isolate, Pseudomonas brassicacearum strain LZ-4, can simultaneously degrade 98% of 6 mM naphthalene and reduce 92.4% of 500 μM hexavalent chromium [Cr (VI)] within 68 h. A draft genome sequence of strain LZ-4 (6,219,082 bp) revealed all the genes in the naphthalene catabolic pathway and some known Cr (VI) reductases. Interestingly, genes encoding naphthalene pathway components were upregulated in the presence of Cr (VI), and Cr (VI) reduction was elevated in the presence of naphthalene. We cloned and expressed these naphthalene catabolic genes and tested for Cr (VI) reduction, and found that NahG reduced 79% of 100 μM Cr (VI) in 5 minutes. Additionally, an nahG deletion mutant lost 52% of its Cr (VI) reduction ability compared to that of the wild-type strain. As nahG encodes a salicylate hydroxylase with flavin adenine dinucleotide (FAD) as a cofactor for electron transfer, Cr (VI) could obtain electrons from NADH through NahG-associated FAD. To the best of our knowledge, this is the first report of a protein involved in a PAH-degradation pathway that can reduce heavy metals, which provides new insights into heavy metal-PAH contamination remediation.
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Affiliation(s)
- Haiying Huang
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, P.R. China
| | - Xuanyu Tao
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, P.R. China
| | - Yiming Jiang
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, P.R. China
| | - Aman Khan
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, P.R. China
| | - Qi Wu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, P.R. China
| | - Xuan Yu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, P.R. China
| | - Dan Wu
- School of Life Sciences, Lanzhou University, Lanzhou, 730000, P.R. China
| | - Yong Chen
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, P.R. China
| | - Zhenmin Ling
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, P.R. China
| | - Pu Liu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, P.R. China
| | - Xiangkai Li
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, P.R. China.
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Weyrauch P, Zaytsev AV, Stephan S, Kocks L, Schmitz OJ, Golding BT, Meckenstock RU. Conversion of cis-2-carboxycyclohexylacetyl-CoA in the downstream pathway of anaerobic naphthalene degradation. Environ Microbiol 2017; 19:2819-2830. [PMID: 28574200 DOI: 10.1111/1462-2920.13806] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 05/23/2017] [Accepted: 05/27/2017] [Indexed: 11/29/2022]
Abstract
The cyclohexane derivative cis-2-(carboxymethyl)cyclohexane-1-carboxylic acid [(1R,2R)-/(1S,2S)-2-(carboxymethyl)cyclohexane-1-carboxylic acid] has previously been identified as metabolite in the pathway of anaerobic degradation of naphthalene by sulfate-reducing bacteria. We tested the corresponding CoA esters of isomers and analogues of this compound for conversion in cell free extracts of the anaerobic naphthalene degraders Desulfobacterium strain N47 and Deltaproteobacterium strain NaphS2. Conversion was only observed for the cis-isomer, verifying that this is a true intermediate and not a dead-end product. Mass-spectrometric analyses confirmed that conversion is performed by an acyl-CoA dehydrogenase and a subsequent hydratase yielding an intermediate with a tertiary hydroxyl-group. We propose that a novel kind of ring-opening lyase is involved in the further catabolic pathway proceeding via pimeloyl-CoA. In contrast to degradation pathways of monocyclic aromatic compounds where ring-cleavage is achieved via hydratases, this lyase might represent a new ring-opening strategy for the degradation of polycyclic compounds. Conversion of the potential downstream metabolites pimeloyl-CoA and glutaryl-CoA was proved in cell free extracts, yielding 2,3-dehydropimeloyl-CoA, 3-hydroxypimeloyl-CoA, 3-oxopimeloyl-CoA, glutaconyl-CoA, crotonyl-CoA, 3-hydroxybutyryl-CoA and acetyl-CoA as observable intermediates. This indicates a link to central metabolism via β-oxidation, a non-decarboxylating glutaryl-CoA dehydrogenase and a subsequent glutaconyl-CoA decarboxylase.
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Affiliation(s)
- Philip Weyrauch
- Biofilm Centre, University of Duisburg-Essen, Essen, Germany.,Institute of Groundwater Ecology, Helmholtz Zentrum München, Neuherberg, Germany
| | - Andrey V Zaytsev
- School of Chemistry, Newcastle University, Newcastle, UK.,Health and Life Sciences, Northumberland University, Newcastle, UK
| | - Susanne Stephan
- Applied Analytical Chemistry, University of Duisburg-Essen, Essen, Germany
| | - Lena Kocks
- Biofilm Centre, University of Duisburg-Essen, Essen, Germany
| | - Oliver J Schmitz
- Applied Analytical Chemistry, University of Duisburg-Essen, Essen, Germany
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Vasconcellos SP, Sierra-Garcia IN, Dellagnezze BM, Vicentini R, Midgley D, Silva CC, Santos Neto EV, Volk H, Hendry P, Oliveira VM. Functional and genetic characterization of hydrocarbon biodegrader and exopolymer-producing clones from a petroleum reservoir metagenomic library. ENVIRONMENTAL TECHNOLOGY 2017; 38:1139-1150. [PMID: 27485801 DOI: 10.1080/09593330.2016.1218940] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Microbial degradation of petroleum is a worldwide issue, which causes physico-chemical changes in its compounds, diminishing its commercial value. Biosurfactants are chemically diverse molecules that can be produced by several microorganisms and can enable microbial access to hydrocarbons. In order to investigate both microbial activities, function-driven screening assays for biosurfactant production and hydrocarbon biodegradation were carried out from a metagenomic fosmid library. It was constructed from the total DNA extracted from aerobic and anaerobic enrichments from a Brazilian biodegraded petroleum sample. A sum of 10 clones were selected in order to evaluate their ability to produce exopolymers (EPS) with emulsifying activity, as well as to characterize the gene sequences, harbored by the fosmid clones, through 454 pyrosequencing. Functional analyses confirmed the ability of some clones to produce surfactant compounds. Regarding hydrocarbon as microbial carbon sources, n-alkane (in mixture or not) and naphthalene were preferentially consumed as substrates. Analysis of sequence data set revealed the presence of genes related to xenobiotics biodegradation and carbohydrate metabolism. These data were corroborated by the results of hydrocarbon biodegradation and biosurfactant production detected in the evaluated clones.
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Affiliation(s)
| | - Isabel N Sierra-Garcia
- b Microbial Resources Division, Research Center for Chemistry , Biology and Agriculture (CPQBA), University of Campinas - UNICAMP , Campinas , SP , Brazil
| | - Bruna M Dellagnezze
- b Microbial Resources Division, Research Center for Chemistry , Biology and Agriculture (CPQBA), University of Campinas - UNICAMP , Campinas , SP , Brazil
| | - Renato Vicentini
- c Center of Molecular Biology and Genetic Engineering - CBMEG/UNICAMP , Campinas , SP , Brazil
| | | | - Cynthia C Silva
- e Department of Microbiology , Federal University of Viçosa - UFV, CEP 36570-000 , Viçosa , MG , Brazil
| | | | | | | | - Valéria M Oliveira
- b Microbial Resources Division, Research Center for Chemistry , Biology and Agriculture (CPQBA), University of Campinas - UNICAMP , Campinas , SP , Brazil
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Martirani-Von Abercron SM, Pacheco D, Benito-Santano P, Marín P, Marqués S. Polycyclic Aromatic Hydrocarbon-Induced Changes in Bacterial Community Structure under Anoxic Nitrate Reducing Conditions. Front Microbiol 2016; 7:1775. [PMID: 27877167 PMCID: PMC5099901 DOI: 10.3389/fmicb.2016.01775] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 10/21/2016] [Indexed: 11/13/2022] Open
Abstract
Although bacterial anaerobic degradation of mono-aromatic compounds has been characterized in depth, the degradation of polycyclic aromatic hydrocarbons (PAHs) such as naphthalene has only started to be understood in sulfate reducing bacteria, and little is known about the anaerobic degradation of PAHs in nitrate reducing bacteria. Starting from a series of environments which had suffered different degrees of hydrocarbon pollution, we used most probable number (MPN) enumeration to detect and quantify the presence of bacterial communities able to degrade several PAHs using nitrate as electron acceptor. We detected the presence of a substantial nitrate reducing community able to degrade naphthalene, 2-methylnaphthalene (2MN), and anthracene in some of the sites. With the aim of isolating strains able to degrade PAHs under denitrifying conditions, we set up a series of enrichment cultures with nitrate as terminal electron acceptor and PAHs as the only carbon source and followed the changes in the bacterial communities throughout the process. Results evidenced changes attributable to the imposed nitrate respiration regime, which in several samples were exacerbated in the presence of the PAHs. The presence of naphthalene or 2MN enriched the community in groups of uncultured and poorly characterized organisms, and notably in the Acidobacteria uncultured group iii1-8, which in some cases was only a minor component of the initial samples. Other phylotypes selected by PAHs in these conditions included Bacilli, which were enriched in naphthalene enrichments. Several nitrate reducing strains showing the capacity to grow on PAHs could be isolated on solid media, although the phenotype could not be reproduced in liquid cultures. Analysis of known PAH anaerobic degradation genes in the original samples and enrichment cultures did not reveal the presence of PAH-related nmsA-like sequences but confirmed the presence of bssA-like genes related to anaerobic toluene degradation. Altogether, our results suggest that PAH degradation by nitrate reducing bacteria may require the contribution of different strains, under culture conditions that still need to be defined.
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Affiliation(s)
| | - Daniel Pacheco
- Estación Experimental del Zaidín, Department of Environmental Protection, Consejo Superior de Investigaciones Científicas Granada, Spain
| | - Patricia Benito-Santano
- Estación Experimental del Zaidín, Department of Environmental Protection, Consejo Superior de Investigaciones Científicas Granada, Spain
| | - Patricia Marín
- Estación Experimental del Zaidín, Department of Environmental Protection, Consejo Superior de Investigaciones Científicas Granada, Spain
| | - Silvia Marqués
- Estación Experimental del Zaidín, Department of Environmental Protection, Consejo Superior de Investigaciones Científicas Granada, Spain
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Wasmund K, Cooper M, Schreiber L, Lloyd KG, Baker BJ, Petersen DG, Jørgensen BB, Stepanauskas R, Reinhardt R, Schramm A, Loy A, Adrian L. Single-Cell Genome and Group-Specific dsrAB Sequencing Implicate Marine Members of the Class Dehalococcoidia (Phylum Chloroflexi) in Sulfur Cycling. mBio 2016; 7:e00266-16. [PMID: 27143384 PMCID: PMC4959651 DOI: 10.1128/mbio.00266-16] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 04/05/2016] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED The marine subsurface sediment biosphere is widely inhabited by bacteria affiliated with the class Dehalococcoidia (DEH), phylum Chloroflexi, and yet little is known regarding their metabolisms. In this report, genomic content from a single DEH cell (DEH-C11) with a 16S rRNA gene that was affiliated with a diverse cluster of 16S rRNA gene sequences prevalent in marine sediments was obtained from sediments of Aarhus Bay, Denmark. The distinctive gene content of this cell suggests metabolic characteristics that differ from those of known DEH and Chloroflexi The presence of genes encoding dissimilatory sulfite reductase (Dsr) suggests that DEH could respire oxidized sulfur compounds, although Chloroflexi have never been implicated in this mode of sulfur cycling. Using long-range PCR assays targeting DEH dsr loci, dsrAB genes were amplified and sequenced from various marine sediments. Many of the amplified dsrAB sequences were affiliated with the DEH Dsr clade, which we propose equates to a family-level clade. This provides supporting evidence for the potential for sulfite reduction by diverse DEH species. DEH-C11 also harbored genes encoding reductases for arsenate, dimethyl sulfoxide, and halogenated organics. The reductive dehalogenase homolog (RdhA) forms a monophyletic clade along with RdhA sequences from various DEH-derived contigs retrieved from available metagenomes. Multiple facts indicate that this RdhA may not be a terminal reductase. The presence of other genes indicated that nutrients and energy may be derived from the oxidation of substituted homocyclic and heterocyclic aromatic compounds. Together, these results suggest that marine DEH play a previously unrecognized role in sulfur cycling and reveal the potential for expanded catabolic and respiratory functions among subsurface DEH. IMPORTANCE Sediments underlying our oceans are inhabited by microorganisms in cell numbers similar to those estimated to inhabit the oceans. Microorganisms in sediments consist of various diverse and uncharacterized groups that contribute substantially to global biogeochemical cycles. Since most subsurface microorganisms continue to evade cultivation, possibly due to very slow growth, we obtained and analyzed genomic information from a representative of one of the most widespread and abundant, yet uncharacterized bacterial groups of the marine subsurface. We describe several key features that may contribute to their widespread distribution, such as respiratory flexibility and the potential to use oxidized sulfur compounds, which are abundant in marine environments, as electron acceptors. Together, these data provide important information that can be used to assist in designing enrichment strategies or other postgenomic studies, while also improving our understanding of the diversity and distribution of dsrAB genes, which are widely used functional marker genes for sulfur-cycling microbes.
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Affiliation(s)
- Kenneth Wasmund
- Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, Research Network Chemistry meets Microbiology, University of Vienna, Vienna, Austria
| | - Myriel Cooper
- Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
| | - Lars Schreiber
- Department of Bioscience, Center for Geomicrobiology, Aarhus University, Aarhus, Denmark
| | - Karen G Lloyd
- Department of Bioscience, Center for Geomicrobiology, Aarhus University, Aarhus, Denmark
| | - Brett J Baker
- Department of Marine Science, University of Texas-Austin, Marine Science Institute, Port Aransas, Texas, USA
| | - Dorthe G Petersen
- Department of Bioscience, Center for Geomicrobiology, Aarhus University, Aarhus, Denmark
| | - Bo Barker Jørgensen
- Department of Bioscience, Center for Geomicrobiology, Aarhus University, Aarhus, Denmark
| | | | | | - Andreas Schramm
- Department of Bioscience, Center for Geomicrobiology, Aarhus University, Aarhus, Denmark
| | - Alexander Loy
- Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, Research Network Chemistry meets Microbiology, University of Vienna, Vienna, Austria
| | - Lorenz Adrian
- Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
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44
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Meckenstock RU, Boll M, Mouttaki H, Koelschbach JS, Cunha Tarouco P, Weyrauch P, Dong X, Himmelberg AM. Anaerobic Degradation of Benzene and Polycyclic Aromatic Hydrocarbons. J Mol Microbiol Biotechnol 2016; 26:92-118. [DOI: 10.1159/000441358] [Citation(s) in RCA: 180] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Aromatic hydrocarbons such as benzene and polycyclic aromatic hydrocarbons (PAHs) are very slowly degraded without molecular oxygen. Here, we review the recent advances in the elucidation of the first known degradation pathways of these environmental hazards. Anaerobic degradation of benzene and PAHs has been successfully documented in the environment by metabolite analysis, compound-specific isotope analysis and microcosm studies. Subsequently, also enrichments and pure cultures were obtained that anaerobically degrade benzene, naphthalene or methylnaphthalene, and even phenanthrene, the largest PAH currently known to be degradable under anoxic conditions. Although such cultures grow very slowly, with doubling times of around 2 weeks, and produce only very little biomass in batch cultures, successful proteogenomic, transcriptomic and biochemical studies revealed novel degradation pathways with exciting biochemical reactions such as for example the carboxylation of naphthalene or the ATP-independent reduction of naphthoyl-coenzyme A. The elucidation of the first anaerobic degradation pathways of naphthalene and methylnaphthalene at the genetic and biochemical level now opens the door to studying the anaerobic metabolism and ecology of anaerobic PAH degraders. This will contribute to assessing the fate of one of the most important contaminant classes in anoxic sediments and aquifers.
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45
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von Netzer F, Kuntze K, Vogt C, Richnow HH, Boll M, Lueders T. Functional Gene Markers for Fumarate-Adding and Dearomatizing Key Enzymes in Anaerobic Aromatic Hydrocarbon Degradation in Terrestrial Environments. J Mol Microbiol Biotechnol 2016; 26:180-94. [PMID: 26959523 DOI: 10.1159/000441946] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Anaerobic degradation is a key process in many environments either naturally or anthropogenically exposed to petroleum hydrocarbons. Considerable advances into the biochemistry and physiology of selected anaerobic degraders have been achieved over the last decades, especially for the degradation of aromatic hydrocarbons. However, researchers have only recently begun to explore the ecology of complex anaerobic hydrocarbon degrader communities directly in their natural habitats, as well as in complex laboratory systems using tools of molecular biology. These approaches have mainly been facilitated by the establishment of a suite of targeted marker gene assays, allowing for rapid and directed insights into the diversity as well as the identity of intrinsic degrader populations and degradation potentials established at hydrocarbon-impacted sites. These are based on genes encoding either peripheral or central key enzymes in aromatic compound breakdown, such as fumarate-adding benzylsuccinate synthases or dearomatizing aryl-coenzyme A reductases, or on aromatic ring-cleaving hydrolases. Here, we review recent advances in this field, explain the different detection methodologies applied, and discuss how the detection of site-specific catabolic gene markers has improved the understanding of processes at contaminated sites. Functional marker gene-based strategies may be vital for the development of a more elaborate population-based assessment and prediction of aromatic degradation potentials in hydrocarbon-impacted environments.
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Affiliation(s)
- Frederick von Netzer
- Helmholtz Zentrum Mx00FC;nchen - German Research Center for Environmental Health, Institute of Groundwater Ecology, Neuherberg, Germany
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46
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Boll M, Einsle O, Ermler U, Kroneck PMH, Ullmann GM. Structure and Function of the Unusual Tungsten Enzymes Acetylene Hydratase and Class II Benzoyl-Coenzyme A Reductase. J Mol Microbiol Biotechnol 2016; 26:119-37. [PMID: 26959374 DOI: 10.1159/000440805] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
In biology, tungsten (W) is exclusively found in microbial enzymes bound to a bis-pyranopterin cofactor (bis-WPT). Previously known W enzymes catalyze redox oxo/hydroxyl transfer reactions by directly coordinating their substrates or products to the metal. They comprise the W-containing formate/formylmethanofuran dehydrogenases belonging to the dimethyl sulfoxide reductase (DMSOR) family and the aldehyde:ferredoxin oxidoreductase (AOR) families, which form a separate enzyme family within the Mo/W enzymes. In the last decade, initial insights into the structure and function of two unprecedented W enzymes were obtained: the acetaldehyde forming acetylene hydratase (ACH) belongs to the DMSOR and the class II benzoyl-coenzyme A (CoA) reductase (BCR) to the AOR family. The latter catalyzes the reductive dearomatization of benzoyl-CoA to a cyclic diene. Both are key enzymes in the degradation of acetylene (ACH) or aromatic compounds (BCR) in strictly anaerobic bacteria. They are unusual in either catalyzing a nonredox reaction (ACH) or a redox reaction without coordinating the substrate or product to the metal (BCR). In organic chemical synthesis, analogous reactions require totally nonphysiological conditions depending on Hg2+ (acetylene hydration) or alkali metals (benzene ring reduction). The structural insights obtained pave the way for biological or biomimetic approaches to basic reactions in organic chemistry.
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Affiliation(s)
- Matthias Boll
- Fakultx00E4;t fx00FC;r Biologie/Mikrobiologie, Institut fx00FC;r Biochemie, Albert-Ludwigs-Universitx00E4;t Freiburg, Freiburg, Germany
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47
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Oulas A, Polymenakou PN, Seshadri R, Tripp HJ, Mandalakis M, Paez-Espino AD, Pati A, Chain P, Nomikou P, Carey S, Kilias S, Christakis C, Kotoulas G, Magoulas A, Ivanova NN, Kyrpides NC. Metagenomic investigation of the geologically unique Hellenic Volcanic Arc reveals a distinctive ecosystem with unexpected physiology. Environ Microbiol 2015; 18:1122-36. [PMID: 26487573 DOI: 10.1111/1462-2920.13095] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 10/16/2015] [Indexed: 11/27/2022]
Abstract
Hydrothermal vents represent a deep, hot, aphotic biosphere where chemosynthetic primary producers, fuelled by chemicals from Earth's subsurface, form the basis of life. In this study, we examined microbial mats from two distinct volcanic sites within the Hellenic Volcanic Arc (HVA). The HVA is geologically and ecologically unique, with reported emissions of CO2 -saturated fluids at temperatures up to 220°C and a notable absence of macrofauna. Metagenomic data reveals highly complex prokaryotic communities composed of chemolithoautotrophs, some methanotrophs, and to our surprise, heterotrophs capable of anaerobic degradation of aromatic hydrocarbons. Our data suggest that aromatic hydrocarbons may indeed be a significant source of carbon in these sites, and instigate additional research into the nature and origin of these compounds in the HVA. Novel physiology was assigned to several uncultured prokaryotic lineages; most notably, a SAR406 representative is attributed with a role in anaerobic hydrocarbon degradation. This dataset, the largest to date from submarine volcanic ecosystems, constitutes a significant resource of novel genes and pathways with potential biotechnological applications.
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Affiliation(s)
- Anastasis Oulas
- Institute of Marine Biology, Biotechnology and Aquaculture, Hellenic Centre for Marine Research, Gournes Pediados, P.O. Box 2214, Heraklion, Crete, 71003, Greece
| | - Paraskevi N Polymenakou
- Institute of Marine Biology, Biotechnology and Aquaculture, Hellenic Centre for Marine Research, Gournes Pediados, P.O. Box 2214, Heraklion, Crete, 71003, Greece
| | - Rekha Seshadri
- Department of Energy, Microbial Genome and Metagenome Program, Joint Genome Institute, Walnut Creek, CA, USA
| | - H James Tripp
- Department of Energy, Microbial Genome and Metagenome Program, Joint Genome Institute, Walnut Creek, CA, USA
| | - Manolis Mandalakis
- Institute of Marine Biology, Biotechnology and Aquaculture, Hellenic Centre for Marine Research, Gournes Pediados, P.O. Box 2214, Heraklion, Crete, 71003, Greece
| | - A David Paez-Espino
- Department of Energy, Microbial Genome and Metagenome Program, Joint Genome Institute, Walnut Creek, CA, USA
| | - Amrita Pati
- Department of Energy, Microbial Genome and Metagenome Program, Joint Genome Institute, Walnut Creek, CA, USA
| | | | - Paraskevi Nomikou
- National and Kapodistrian University of Athens, Faculty of Geology and Geoenvironment, Athens, Greece
| | - Steven Carey
- Graduate School of Oceanography, University of Rhode Island, Kingston, RI, USA
| | - Stephanos Kilias
- National and Kapodistrian University of Athens, Faculty of Geology and Geoenvironment, Athens, Greece
| | - Christos Christakis
- Institute of Marine Biology, Biotechnology and Aquaculture, Hellenic Centre for Marine Research, Gournes Pediados, P.O. Box 2214, Heraklion, Crete, 71003, Greece
| | - Georgios Kotoulas
- Institute of Marine Biology, Biotechnology and Aquaculture, Hellenic Centre for Marine Research, Gournes Pediados, P.O. Box 2214, Heraklion, Crete, 71003, Greece
| | - Antonios Magoulas
- Institute of Marine Biology, Biotechnology and Aquaculture, Hellenic Centre for Marine Research, Gournes Pediados, P.O. Box 2214, Heraklion, Crete, 71003, Greece
| | - Natalia N Ivanova
- Department of Energy, Microbial Genome and Metagenome Program, Joint Genome Institute, Walnut Creek, CA, USA
| | - Nikos C Kyrpides
- Department of Energy, Microbial Genome and Metagenome Program, Joint Genome Institute, Walnut Creek, CA, USA.,Department of Biological Sciences, King Abdulaziz, Jeddah, Saudia Arabia
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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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Kümmel S, Herbst FA, Bahr A, Duarte M, Pieper DH, Jehmlich N, Seifert J, von Bergen M, Bombach P, Richnow HH, Vogt C. Anaerobic naphthalene degradation by sulfate-reducing Desulfobacteraceae from various anoxic aquifers. FEMS Microbiol Ecol 2015; 91:fiv006. [PMID: 25764566 DOI: 10.1093/femsec/fiv006] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Polycyclic aromatic hydrocarbons (PAH) are widespread and persistent environmental contaminants, especially in oxygen-free environments. The occurrence of anaerobic PAH-degrading bacteria and their underlying metabolic pathways are rarely known. In this study, PAH degraders were enriched in laboratory microcosms under sulfate-reducing conditions using groundwater and sediment samples from four PAH-contaminated aquifers. Five enrichment cultures were obtained showing sulfate-dependent naphthalene degradation. Mineralization of naphthalene was demonstrated by the formation of sulfide concomitant with the depletion of naphthalene and the development of (13)C-labeled CO2 from [(13)C6]-naphthalene. 16S rRNA gene and metaproteome analyses revealed that organisms related to Desulfobacterium str. N47 were the main naphthalene degraders in four enrichment cultures. Protein sequences highly similar to enzymes of the naphthalene degradation pathway of N47 were identified, suggesting that naphthalene was activated by a carboxylase, and that the central metabolite 2-naphthoyl-CoA was further reduced by two reductases. The data indicate an importance of members of the family Desulfobacteraceae for naphthalene degradation under sulfate-reducing conditions in freshwater environments.
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Affiliation(s)
- Steffen Kümmel
- UFZ - Helmholtz Centre for Environmental Research, Department of Isotope Biogeochemistry, Permoserstraße 15, D-04318 Leipzig, Germany University of Freiburg, Faculty of Biology, Schaenzlestraße 1, D-79104 Freiburg, Germany
| | - Florian-Alexander Herbst
- UFZ - Helmholtz Centre for Environmental Research, Department of Proteomics, Permoserstraße 15, D-04318 Leipzig, Germany
| | - Arne Bahr
- UFZ - Helmholtz Centre for Environmental Research, Department of Isotope Biogeochemistry, Permoserstraße 15, D-04318 Leipzig, Germany
| | - Márcia Duarte
- Helmholtz Centre for Infection Research - HZI, Microbial Interactions and Processes Research Group, Inhoffenstrasse 7, D-38124 Braunschweig, Germany
| | - Dietmar H Pieper
- Helmholtz Centre for Infection Research - HZI, Microbial Interactions and Processes Research Group, Inhoffenstrasse 7, D-38124 Braunschweig, Germany
| | - Nico Jehmlich
- UFZ - Helmholtz Centre for Environmental Research, Department of Proteomics, Permoserstraße 15, D-04318 Leipzig, Germany
| | - Jana Seifert
- University of Freiburg, Faculty of Biology, Schaenzlestraße 1, D-79104 Freiburg, Germany University of Hohenheim, Faculty of Agricultural Sciences, Emil-Wolff-Straße 8-10, D-70599 Stuttgart, Germany
| | - Martin von Bergen
- University of Freiburg, Faculty of Biology, Schaenzlestraße 1, D-79104 Freiburg, Germany UFZ - Helmholtz Centre for Environmental Research, Department of Metabolomics, Permoserstraße 15, D-04318 Leipzig, Germany
| | - Petra Bombach
- UFZ - Helmholtz Centre for Environmental Research, Department of Isotope Biogeochemistry, Permoserstraße 15, D-04318 Leipzig, Germany
| | - Hans H Richnow
- UFZ - Helmholtz Centre for Environmental Research, Department of Isotope Biogeochemistry, Permoserstraße 15, D-04318 Leipzig, Germany
| | - Carsten Vogt
- UFZ - Helmholtz Centre for Environmental Research, Department of Isotope Biogeochemistry, Permoserstraße 15, D-04318 Leipzig, Germany
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50
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Estelmann S, Blank I, Feldmann A, Boll M. Two distinct old yellow enzymes are involved in naphthyl ring reduction during anaerobic naphthalene degradation. Mol Microbiol 2014; 95:162-72. [PMID: 25424741 DOI: 10.1111/mmi.12875] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/14/2014] [Indexed: 11/29/2022]
Abstract
The 2-naphthoyl-coenzyme A (NCoA) reductase (NCR) is so far the only characterized enzyme involved in the anaerobic degradation of the environmentally relevant polycyclic aromatic hydrocarbons. The old yellow enzyme (OYE) family member apparently reduced the nonactivated naphthyl ring to 5,6,7,8-tetrahydro-2-napthoyl-CoA (THNCoA). In this work, the candidate genes of three NCRs from the sulphate-reducing, naphthalene-degrading N47 and NaphS2 cultures were expressed in Escherichia coli. The isolated products contained flavin adenine dinucleotide (FAD), flavin mononucleotide (FMN) a [4Fe-4S] cluster and catalyzed only the two-electron reduction of NCoA to 5,6-dihydro-2-naphthoyl-CoA (5,6-DHNCoA) at a very negative E°' = -493 mV. All NCRs exhibited high NCoA-forming DHNCoA oxidase activities that are proposed to be involved in oxygen-detoxification during naphthalene degradation. Extracts of N47 and NaphS2 catalyzed the reduction of 5,6-DHNCoA to THNCoA. Genes putatively coding for 5,6-DHNCR from N47 and NaphS2 were heterologously expressed in E. coli. The enriched enzyme products specifically catalyzed the reduction of 5,6-DHNCoA to THNCoA at E°' = -375 mV. With the three NCRs and two 5,6-DHNCRs, five OYEs have been characterized that are involved in the reduction of the nonsubstituted naphthyl-ring system; these unprecedented enzymatic reactions expand our knowledge of the functional diversity of OYE.
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Affiliation(s)
- Sebastian Estelmann
- Microbiology, Faculty of Biology, University of Freiburg, Schänzlestr. 1, D-79104, Freiburg, Germany
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