1
|
Hink L, Holzinger A, Sandfeld T, Weig AR, Schramm A, Feldhaar H, Horn MA. Microplastic ingestion affects hydrogen production and microbiomes in the gut of the terrestrial isopod Porcellio scaber. Environ Microbiol 2023; 25:2776-2791. [PMID: 37041018 DOI: 10.1111/1462-2920.16386] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 03/31/2023] [Indexed: 04/13/2023]
Abstract
Microplastic (MP) is an environmental burden and enters food webs via ingestion by macrofauna, including isopods (Porcellio scaber) in terrestrial ecosystems. Isopods represent ubiquitously abundant, ecologically important detritivores. However, MP-polymer specific effects on the host and its gut microbiota are unknown. We tested the hypothesis that biodegradable (polylactic acid [PLA]) and non-biodegradable (polyethylene terephthalate [PET]; polystyrene [PS]) MPs have contrasting effects on P. scaber mediated by changes of the gut microbiota. The isopod fitness after an 8-week MP-exposure was generally unaffected, although the isopods showed avoidance behaviour to PS-food. MP-polymer specific effects on gut microbes were detected, including a stimulation of microbial activity by PLA compared with MP-free controls. PLA stimulated hydrogen emission from isopod guts, while PET and PS were inhibitory. We roughly estimated 107 kg year-1 hydrogen emitted from the isopods globally and identified their guts as anoxic, significant mobile sources of reductant for soil microbes despite the absence of classical obligate anaerobes, likely due to Enterobacteriaceae-related fermentation activities that were stimulated by lactate generated during PLA-degradation. The findings suggest negative effects of PET and PS on gut fermentation, modulation of important isopod hydrogen emissions by MP pollution and the potential of MP to affect terrestrial food webs.
Collapse
Affiliation(s)
- Linda Hink
- Institute of Microbiology, Leibniz University Hannover, Hannover, Germany
| | - Anja Holzinger
- Animal Population Ecology, Bayreuth Center of Ecology and Environmental Research (BayCEER), University of Bayreuth, Bayreuth, Germany
| | - Tobias Sandfeld
- Department of Biology, Section for Microbiology, Aarhus University, Aarhus, Denmark
| | - Alfons R Weig
- Genomics and Bioinformatics, University of Bayreuth, Bayreuth, Germany
| | - Andreas Schramm
- Department of Biology, Section for Microbiology, Aarhus University, Aarhus, Denmark
| | - Heike Feldhaar
- Animal Population Ecology, Bayreuth Center of Ecology and Environmental Research (BayCEER), University of Bayreuth, Bayreuth, Germany
| | - Marcus A Horn
- Institute of Microbiology, Leibniz University Hannover, Hannover, Germany
| |
Collapse
|
2
|
Dey S, Kasai T, Katayama A. Promotion of biological H 2 (Bio-H 2) production by the nitrogen-fixing anaerobic microbial consortia using humin, a solid-phase humic substance. J Biosci Bioeng 2022; 134:144-152. [PMID: 35644797 DOI: 10.1016/j.jbiosc.2022.04.011] [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: 09/28/2021] [Revised: 04/23/2022] [Accepted: 04/29/2022] [Indexed: 11/30/2022]
Abstract
Dark fermentative biological hydrogen (Bio-H2) production is expected to be a clean and sustainable H2 production technology, and the technologies have been studied to increase in the product yield as index. This study achieved high product yields of Bio-H2 using nitrogen-fixing consortia under nitrogen-deficient conditions with glucose or mannitol as substrate and humin as the extracellular electron mediator: 4.12 mol-H2/mol-glucose and 3.12 mol-H2/mol-mannitol. The high Bio-H2 production was observed under the conditions where both nitrogenase and hydrogenase were active in the presence of humin. Nitrogenase activity was confirmed by acetylene reduction activity and hydrogenase activity by Bio-H2 production under nitrogenase-inhibiting conditions with NH4NO3. [Fe-Fe] hydrogenase detected by a specific PCR and acetate, butyrate, formate, lactate, and pyruvate produced as by-products suggested the involvement of both pyruvate-ferredoxin-oxidoreductase and pyruvate formate lyase pathways in Bio-H2 production. Humin promoted the Bio-H2 production beyond the capacity of the consortium, which had reached saturation with the optimum concentrations of glucose and mannitol. Carbon balance suggested the concurrent H2 consumption by hydrogenotrophic methanogenesis and acetogenesis. Bio-H2 production of the washed and starved consortium with reduced humin under conditions with or without NH4NO3 suggests that humin promoted hydrogenase and nitrogenase activity by donating extracellular electrons. Clostridium and Ruminococcus in the consortia were considered major hydrogen producers. Thus, this study demonstrated the outstanding potential of nitrogen-fixing consortia under nitrogen-deficient conditions with humin as an extracellular electron mediator for dark fermentative Bio-H2 production with high yields.
Collapse
Affiliation(s)
- Sujan Dey
- Department of Civil and Environmental Engineering, Graduate School of Engineering, Nagoya University, Tokai National Higher Education and Research System, Chikusa, Nagoya 464-8603, Japan; Institute of Materials and Systems for Sustainability, Nagoya University, Tokai National Higher Education and Research System, Chikusa, Nagoya 464-8603, Japan
| | - Takuya Kasai
- Department of Civil and Environmental Engineering, Graduate School of Engineering, Nagoya University, Tokai National Higher Education and Research System, Chikusa, Nagoya 464-8603, Japan; Institute of Materials and Systems for Sustainability, Nagoya University, Tokai National Higher Education and Research System, Chikusa, Nagoya 464-8603, Japan
| | - Arata Katayama
- Department of Civil and Environmental Engineering, Graduate School of Engineering, Nagoya University, Tokai National Higher Education and Research System, Chikusa, Nagoya 464-8603, Japan; Institute of Materials and Systems for Sustainability, Nagoya University, Tokai National Higher Education and Research System, Chikusa, Nagoya 464-8603, Japan.
| |
Collapse
|
3
|
Ma L, Wu G, Yang J, Huang L, Phurbu D, Li WJ, Jiang H. Distribution of Hydrogen-Producing Bacteria in Tibetan Hot Springs, China. Front Microbiol 2021; 12:569020. [PMID: 34367076 PMCID: PMC8334365 DOI: 10.3389/fmicb.2021.569020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 06/08/2021] [Indexed: 11/13/2022] Open
Abstract
Investigating the distribution of hydrogen-producing bacteria (HPB) is of great significance to understanding the source of biological hydrogen production in geothermal environments. Here, we explored the compositions of HPB populations in the sediments of hot springs from the Daggyai, Quzhuomu, Quseyongba, and Moluojiang geothermal zones on the Tibetan Plateau, with the use of Illumina MiSeq high-throughput sequencing of 16S rRNA genes and hydA genes. In the present study, the hydA genes were successfully amplified from the hot springs with a temperature of 46–87°C. The hydA gene phylogenetic analysis showed that the top three phyla of the HPB populations were Bacteroidetes (14.48%), Spirochaetes (14.12%), and Thermotogae (10.45%), while Proteobacteria were absent in the top 10 of the HPB populations, although Proteobacteria were dominant in the 16S rRNA gene sequences. Canonical correspondence analysis results indicate that the HPB community structure in the studied Tibetan hot springs was correlated with various environmental factors, such as temperature, pH, and elevation. The HPB community structure also showed a spatial distribution pattern; samples from the same area showed similar community structures. Furthermore, one HPB isolate affiliated with Firmicutes was obtained and demonstrated the capacity of hydrogen production. These results are important for us to understand the distribution and function of HPB in hot springs.
Collapse
Affiliation(s)
- Li Ma
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China
| | - Geng Wu
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China
| | - Jian Yang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China
| | - Liuqin Huang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China
| | - Dorji Phurbu
- Tibet Plateau Institute of Biology, Lhasa, China
| | - Wen-Jun Li
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Hongchen Jiang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China
| |
Collapse
|
4
|
Piché-Choquette S, Constant P. Molecular Hydrogen, a Neglected Key Driver of Soil Biogeochemical Processes. Appl Environ Microbiol 2019; 85:e02418-18. [PMID: 30658976 PMCID: PMC6414374 DOI: 10.1128/aem.02418-18] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The atmosphere of the early Earth is hypothesized to have been rich in reducing gases such as hydrogen (H2). H2 has been proposed as the first electron donor leading to ATP synthesis due to its ubiquity throughout the biosphere as well as its ability to easily diffuse through microbial cells and its low activation energy requirement. Even today, hydrogenase enzymes enabling the production and oxidation of H2 are found in thousands of genomes spanning the three domains of life across aquatic, terrestrial, and even host-associated ecosystems. Even though H2 has already been proposed as a universal growth and maintenance energy source, its potential contribution as a driver of biogeochemical cycles has received little attention. Here, we bridge this knowledge gap by providing an overview of the classification, distribution, and physiological role of hydrogenases. Distribution of these enzymes in various microbial functional groups and recent experimental evidence are finally integrated to support the hypothesis that H2-oxidizing microbes are keystone species driving C cycling along O2 concentration gradients found in H2-rich soil ecosystems. In conclusion, we suggest focusing on the metabolic flexibility of H2-oxidizing microbes by combining community-level and individual-level approaches aiming to decipher the impact of H2 on C cycling and the C-cycling potential of H2-oxidizing microbes, via both culture-dependent and culture-independent methods, to give us more insight into the role of H2 as a driver of biogeochemical processes.
Collapse
|
5
|
Schuchmann K, Chowdhury NP, Müller V. Complex Multimeric [FeFe] Hydrogenases: Biochemistry, Physiology and New Opportunities for the Hydrogen Economy. Front Microbiol 2018; 9:2911. [PMID: 30564206 PMCID: PMC6288185 DOI: 10.3389/fmicb.2018.02911] [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: 08/30/2018] [Accepted: 11/13/2018] [Indexed: 12/03/2022] Open
Abstract
Hydrogenases are key enzymes of the energy metabolism of many microorganisms. Especially in anoxic habitats where molecular hydrogen (H2) is an important intermediate, these enzymes are used to expel excess reducing power by reducing protons or they are used for the oxidation of H2 as energy and electron source. Despite the fact that hydrogenases catalyze the simplest chemical reaction of reducing two protons with two electrons it turned out that they are often parts of multimeric enzyme complexes catalyzing complex chemical reactions with a multitude of functions in the metabolism. Recent findings revealed multimeric hydrogenases with so far unknown functions particularly in bacteria from the class Clostridia. The discovery of [FeFe] hydrogenases coupled to electron bifurcating subunits solved the enigma of how the otherwise highly endergonic reduction of the electron carrier ferredoxin can be carried out and how H2 production from NADH is possible. Complexes of [FeFe] hydrogenases with formate dehydrogenases revealed a novel enzymatic coupling of the two electron carriers H2 and formate. These novel hydrogenase enzyme complex could also contribute to biotechnological H2 production and H2 storage, both processes essential for an envisaged economy based on H2 as energy carrier.
Collapse
Affiliation(s)
- Kai Schuchmann
- Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Frankfurt am Main, Germany
| | - Nilanjan Pal Chowdhury
- Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Frankfurt am Main, Germany
| | - Volker Müller
- Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Frankfurt am Main, Germany
| |
Collapse
|
6
|
Min X, Zhang M, Yuan S, Ge S, Liu X, Zeng X, Xia N. Using MOEA with Redistribution and Consensus Branches to Infer Phylogenies. Int J Mol Sci 2017; 19:E62. [PMID: 29278391 PMCID: PMC5796012 DOI: 10.3390/ijms19010062] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 12/06/2017] [Accepted: 12/22/2017] [Indexed: 11/16/2022] Open
Abstract
In recent years, to infer phylogenies, which are NP-hard problems, more and more research has focused on using metaheuristics. Maximum Parsimony and Maximum Likelihood are two effective ways to conduct inference. Based on these methods, which can also be considered as the optimal criteria for phylogenies, various kinds of multi-objective metaheuristics have been used to reconstruct phylogenies. However, combining these two time-consuming methods results in those multi-objective metaheuristics being slower than a single objective. Therefore, we propose a novel, multi-objective optimization algorithm, MOEA-RC, to accelerate the processes of rebuilding phylogenies using structural information of elites in current populations. We compare MOEA-RC with two representative multi-objective algorithms, MOEA/D and NAGA-II, and a non-consensus version of MOEA-RC on three real-world datasets. The result is, within a given number of iterations, MOEA-RC achieves better solutions than the other algorithms.
Collapse
Affiliation(s)
- Xiaoping Min
- School of Information Science and Technology, Xiamen University, Xiamen 361102, China.
- National Institute of Diagnostics and Vaccine Development in Infectious Diseases, Xiamen University, Xiamen 361102, China.
| | - Mouzhao Zhang
- School of Information Science and Technology, Xiamen University, Xiamen 361102, China.
| | - Sisi Yuan
- School of Information Science and Technology, Xiamen University, Xiamen 361102, China.
| | - Shengxiang Ge
- National Institute of Diagnostics and Vaccine Development in Infectious Diseases, Xiamen University, Xiamen 361102, China.
| | - Xiangrong Liu
- School of Information Science and Technology, Xiamen University, Xiamen 361102, China.
| | - Xiangxiang Zeng
- School of Information Science and Technology, Xiamen University, Xiamen 361102, China.
| | - Ningshao Xia
- National Institute of Diagnostics and Vaccine Development in Infectious Diseases, Xiamen University, Xiamen 361102, China.
| |
Collapse
|
7
|
Metagenome Analysis: a Powerful Tool for Enzyme Bioprospecting. Appl Biochem Biotechnol 2017; 183:636-651. [PMID: 28815469 DOI: 10.1007/s12010-017-2568-3] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 07/24/2017] [Indexed: 01/05/2023]
Abstract
Microorganisms are found throughout every corner of nature, and vast number of microorganisms is difficult to cultivate by classical microbiological techniques. The advent of metagenomics has revolutionized the field of microbial biotechnology. Metagenomics allow the recovery of genetic material directly from environmental niches without any cultivation techniques. Currently, metagenomic tools are widely employed as powerful tools to isolate and identify enzymes with novel biocatalytic activities from the uncultivable component of microbial communities. The employment of next-generation sequencing techniques for metagenomics resulted in the generation of large sequence data sets derived from various environments, such as soil, the human body and ocean water. This review article describes the state-of-the-art techniques and tools in metagenomics and discusses the potential of metagenomic approaches for the bioprospecting of industrial enzymes from various environmental samples. We also describe the unusual novel enzymes discovered via metagenomic approaches and discuss the future prospects for metagenome technologies.
Collapse
|
8
|
Therien JB, Artz JH, Poudel S, Hamilton TL, Liu Z, Noone SM, Adams MWW, King PW, Bryant DA, Boyd ES, Peters JW. The Physiological Functions and Structural Determinants of Catalytic Bias in the [FeFe]-Hydrogenases CpI and CpII of Clostridium pasteurianum Strain W5. Front Microbiol 2017; 8:1305. [PMID: 28747909 PMCID: PMC5506873 DOI: 10.3389/fmicb.2017.01305] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 06/28/2017] [Indexed: 12/02/2022] Open
Abstract
The first generation of biochemical studies of complex, iron-sulfur-cluster-containing [FeFe]-hydrogenases and Mo-nitrogenase were carried out on enzymes purified from Clostridium pasteurianum (strain W5). Previous studies suggested that two distinct [FeFe]-hydrogenases are expressed differentially under nitrogen-fixing and non-nitrogen-fixing conditions. As a result, the first characterized [FeFe]-hydrogenase (CpI) is presumed to have a primary role in central metabolism, recycling reduced electron carriers that accumulate during fermentation via proton reduction. A role for capturing reducing equivalents released as hydrogen during nitrogen fixation has been proposed for the second hydrogenase, CpII. Biochemical characterization of CpI and CpII indicated CpI has extremely high hydrogen production activity in comparison to CpII, while CpII has elevated hydrogen oxidation activity in comparison to CpI when assayed under the same conditions. This suggests that these enzymes have evolved a catalytic bias to support their respective physiological functions. Using the published genome of C. pasteurianum (strain W5) hydrogenase sequences were identified, including the already known [NiFe]-hydrogenase, CpI, and CpII sequences, and a third hydrogenase, CpIII was identified in the genome as well. Quantitative real-time PCR experiments were performed in order to analyze transcript abundance of the hydrogenases under diazotrophic and non-diazotrophic growth conditions. There is a markedly reduced level of CpI gene expression together with concomitant increases in CpII gene expression under nitrogen-fixing conditions. Structure-based analyses of the CpI and CpII sequences reveal variations in their catalytic sites that may contribute to their alternative physiological roles. This work demonstrates that the physiological roles of CpI and CpII are to evolve and to consume hydrogen, respectively, in concurrence with their catalytic activities in vitro, with CpII capturing excess reducing equivalents under nitrogen fixation conditions. Comparison of the primary sequences of CpI and CpII and their homologs provides an initial basis for identifying key structural determinants that modulate hydrogen production and hydrogen oxidation activities.
Collapse
Affiliation(s)
- Jesse B Therien
- Department of Chemistry and Biochemistry, Montana State University, BozemanMT, United States
| | - Jacob H Artz
- Department of Chemistry and Biochemistry, Montana State University, BozemanMT, United States
| | - Saroj Poudel
- Department of Microbiology and Immunology, Montana State University, BozemanMT, United States
| | - Trinity L Hamilton
- Department of Chemistry and Biochemistry, Montana State University, BozemanMT, United States
| | - Zhenfeng Liu
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University ParkPA, United States
| | - Seth M Noone
- National Renewable Energy Laboratory, Biosciences Center, GoldenCO, United States
| | - Michael W W Adams
- Department of Biochemistry & Molecular Biology, University of Georgia, AthensGA, United States
| | - Paul W King
- National Renewable Energy Laboratory, Biosciences Center, GoldenCO, United States
| | - Donald A Bryant
- Department of Chemistry and Biochemistry, Montana State University, BozemanMT, United States.,Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University ParkPA, United States
| | - Eric S Boyd
- Department of Microbiology and Immunology, Montana State University, BozemanMT, United States
| | - John W Peters
- Department of Chemistry and Biochemistry, Montana State University, BozemanMT, United States
| |
Collapse
|
9
|
Baba R, Morita M, Asakawa S, Watanabe T. Transcription of [FeFe]-Hydrogenase Genes during H 2 Production in Clostridium and Desulfovibrio spp. Isolated from a Paddy Field Soil. Microbes Environ 2017; 32:125-132. [PMID: 28502969 PMCID: PMC5478535 DOI: 10.1264/jsme2.me16171] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Changes in the relative abundances of the transcripts of hydA gene paralogs for [FeFe]-hydrogenase in Clostridium sp. strain H2 and Desulfovibrio sp. strain A1 isolated from paddy field soil were analyzed during H2 production. Strains H2 and A1 had at least five and two phylogenetically different hydA genes, respectively. The relative abundances of their hydA transcripts differed among the paralogs and H2 production activity changed in a manner that depended on the growth phase and conditions. Increases or decreases in the relative abundances of the transcripts of two out of five hydA genes in strain H2 correlated with changes in H2 production rates, whereas those of the others remained unchanged or decreased. In strain A1, the relative abundances of the transcripts of two hydA genes differed between monoculture, sulfate-reducing, and syntrophic, methanogenic conditions. The relative abundance of the transcripts of one hydA gene, predicted to encode a cytosolic [FeFe]-hydrogenase, was higher under syntrophic, methanogenic conditions than sulfate-reducing conditions, while that of the transcripts of the other hydA gene decreased with time under both conditions. This study showed that the transcription of the hydA gene during growth with active H2 production was differently regulated among the paralogs in H2 producers isolated from paddy field soil.
Collapse
Affiliation(s)
- Ryuko Baba
- Laboratory of Soil Biology and Chemistry, Department of Biological Mechanisms and Functions, Graduate School of Bioagricultural Sciences, Nagoya University
| | - Mayumi Morita
- Laboratory of Soil Biology and Chemistry, School of Agricultural Sciences, Nagoya University
| | - Susumu Asakawa
- Laboratory of Soil Biology and Chemistry, Department of Biological Mechanisms and Functions, Graduate School of Bioagricultural Sciences, Nagoya University
| | - Takeshi Watanabe
- Laboratory of Soil Biology and Chemistry, Department of Biological Mechanisms and Functions, Graduate School of Bioagricultural Sciences, Nagoya University
| |
Collapse
|
10
|
Ziganshin AM, Schmidt T, Lv Z, Liebetrau J, Richnow HH, Kleinsteuber S, Nikolausz M. Reduction of the hydraulic retention time at constant high organic loading rate to reach the microbial limits of anaerobic digestion in various reactor systems. BIORESOURCE TECHNOLOGY 2016; 217:62-71. [PMID: 26853042 DOI: 10.1016/j.biortech.2016.01.096] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2015] [Revised: 01/22/2016] [Accepted: 01/25/2016] [Indexed: 05/27/2023]
Abstract
The effects of hydraulic retention time (HRT) reduction at constant high organic loading rate on the activity of hydrogen-producing bacteria and methanogens were investigated in reactors digesting thin stillage. Stable isotope fingerprinting was additionally applied to assess methanogenic pathways. Based on hydA gene transcripts, Clostridiales was the most active hydrogen-producing order in continuous stirred tank reactor (CSTR), fixed-bed reactor (FBR) and anaerobic sequencing batch reactor (ASBR), but shorter HRT stimulated the activity of Spirochaetales. Further decreasing HRT diminished Spirochaetales activity in systems with biomass retention. Based on mcrA gene transcripts, Methanoculleus and Methanosarcina were the predominantly active in CSTR and ASBR, whereas Methanosaeta and Methanospirillum activity was more significant in stably performing FBR. Isotope values indicated the predominance of aceticlastic pathway in FBR. Interestingly, an increased activity of Methanosaeta was observed during shortening HRT in CSTR and ASBR despite high organic acids concentrations, what was supported by stable isotope data.
Collapse
Affiliation(s)
- Ayrat M Ziganshin
- Department of Microbiology, Kazan (Volga Region) Federal University, Kazan 420008, The Republic of Tatarstan, Russia
| | - Thomas Schmidt
- Department of Biochemical Conversion, Deutsches Biomasseforschungszentrum gGmbH, 04347 Leipzig, Germany; Faculty of Agricultural and Environmental Sciences, University of Rostock, 18059 Rostock, Germany
| | - Zuopeng Lv
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research - UFZ, 04318 Leipzig, Germany
| | - Jan Liebetrau
- Department of Biochemical Conversion, Deutsches Biomasseforschungszentrum gGmbH, 04347 Leipzig, Germany
| | - Hans Hermann Richnow
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, 04318 Leipzig, Germany
| | - Sabine Kleinsteuber
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research - UFZ, 04318 Leipzig, Germany
| | - Marcell Nikolausz
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research - UFZ, 04318 Leipzig, Germany.
| |
Collapse
|
11
|
Baba R, Asakawa S, Watanabe T. H2-Producing Bacterial Community during Rice Straw Decomposition in Paddy Field Soil: Estimation by an Analysis of [FeFe]-Hydrogenase Gene Transcripts. Microbes Environ 2016; 31:226-33. [PMID: 27319579 PMCID: PMC5017798 DOI: 10.1264/jsme2.me16036] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 04/30/2016] [Indexed: 11/29/2022] Open
Abstract
The transcription patterns of [FeFe]-hydrogenase genes (hydA), which encode the enzymes responsible for H2 production, were investigated during rice straw decomposition in paddy soil using molecular biological techniques. Paddy soil amended with and without rice straw was incubated under anoxic conditions. RNA was extracted from the soil, and three clone libraries of hydA were constructed using RNAs obtained from samples in the initial phase of rice straw decomposition (day 1 with rice straw), methanogenic phase of rice straw decomposition (day 14 with rice straw), and under a non-amended condition (day 14 without rice straw). hydA genes related to Proteobacteria, Firmicutes, Bacteroidetes, Chloroflexi, and Thermotogae were mainly transcribed in paddy soil samples; however, their proportions markedly differed among the libraries. Deltaproteobacteria-related hydA genes were predominantly transcribed on day 1 with rice straw, while various types of hydA genes related to several phyla were transcribed on day 14 with rice straw. Although the diversity of transcribed hydA was significantly higher in the library on day 14 with rice straw than the other two libraries, the composition of hydA transcripts in the library was similar to that in the library on day 14 without rice straw. These results indicate that the composition of active H2 producers and/or H2 metabolic patterns dynamically change during rice straw decomposition in paddy soil.
Collapse
Affiliation(s)
- Ryuko Baba
- Laboratory of Soil Biology and Chemistry, Department of Biological Mechanisms and Functions, Graduate School of Bioagricultural Sciences, Nagoya UniversityFurocho, Chikusa, Nagoya 464–8601Japan
| | - Susumu Asakawa
- Laboratory of Soil Biology and Chemistry, Department of Biological Mechanisms and Functions, Graduate School of Bioagricultural Sciences, Nagoya UniversityFurocho, Chikusa, Nagoya 464–8601Japan
| | - Takeshi Watanabe
- Laboratory of Soil Biology and Chemistry, Department of Biological Mechanisms and Functions, Graduate School of Bioagricultural Sciences, Nagoya UniversityFurocho, Chikusa, Nagoya 464–8601Japan
| |
Collapse
|
12
|
Mei N, Postec A, Monnin C, Pelletier B, Payri CE, Ménez B, Frouin E, Ollivier B, Erauso G, Quéméneur M. Metagenomic and PCR-Based Diversity Surveys of [FeFe]-Hydrogenases Combined with Isolation of Alkaliphilic Hydrogen-Producing Bacteria from the Serpentinite-Hosted Prony Hydrothermal Field, New Caledonia. Front Microbiol 2016; 7:1301. [PMID: 27625634 PMCID: PMC5003875 DOI: 10.3389/fmicb.2016.01301] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 08/08/2016] [Indexed: 12/01/2022] Open
Abstract
High amounts of hydrogen are emitted in the serpentinite-hosted hydrothermal field of the Prony Bay (PHF, New Caledonia), where high-pH (~11), low-temperature (< 40°C), and low-salinity fluids are discharged in both intertidal and shallow submarine environments. In this study, we investigated the diversity and distribution of potentially hydrogen-producing bacteria in Prony hyperalkaline springs by using metagenomic analyses and different PCR-amplified DNA sequencing methods. The retrieved sequences of hydA genes, encoding the catalytic subunit of [FeFe]-hydrogenases and, used as a molecular marker of hydrogen-producing bacteria, were mainly related to those of Firmicutes and clustered into two distinct groups depending on sampling locations. Intertidal samples were dominated by new hydA sequences related to uncultured Firmicutes retrieved from paddy soils, while submarine samples were dominated by diverse hydA sequences affiliated with anaerobic and/or thermophilic submarine Firmicutes pertaining to the orders Thermoanaerobacterales or Clostridiales. The novelty and diversity of these [FeFe]-hydrogenases may reflect the unique environmental conditions prevailing in the PHF (i.e., high-pH, low-salt, mesothermic fluids). In addition, novel alkaliphilic hydrogen-producing Firmicutes (Clostridiales and Bacillales) were successfully isolated from both intertidal and submarine PHF chimney samples. Both molecular and cultivation-based data demonstrated the ability of Firmicutes originating from serpentinite-hosted environments to produce hydrogen by fermentation, potentially contributing to the molecular hydrogen balance in situ.
Collapse
Affiliation(s)
- Nan Mei
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIOMarseille, France
| | - Anne Postec
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIOMarseille, France
| | - Christophe Monnin
- GET UMR5563 (Centre National de la Recherche Scientifique/UPS/IRD/CNES), Géosciences Environnement ToulouseToulouse, France
| | - Bernard Pelletier
- Institut pour la Recherche et le Développement (IRD) Centre de Nouméa, MIO UM 110Nouméa, Nouvelle-Calédonie
| | - Claude E. Payri
- Institut pour la Recherche et le Développement (IRD) Centre de Nouméa, MIO UM 110Nouméa, Nouvelle-Calédonie
| | - Bénédicte Ménez
- Institut de Physique du Globe de Paris, Sorbonne Paris Cité, Univ Paris Diderot, Centre National de la Recherche ScientifiqueParis, France
| | - Eléonore Frouin
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIOMarseille, France
| | - Bernard Ollivier
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIOMarseille, France
| | - Gaël Erauso
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIOMarseille, France
| | - Marianne Quéméneur
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIOMarseille, France
| |
Collapse
|
13
|
Hunger S, Schmidt O, Gößner AS, Drake HL. Formate-derived H2, a driver of hydrogenotrophic processes in the root-zone of a methane-emitting fen. Environ Microbiol 2016; 18:3106-19. [DOI: 10.1111/1462-2920.13301] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 03/12/2016] [Indexed: 02/04/2023]
Affiliation(s)
- Sindy Hunger
- Department of Ecological Microbiology; University of Bayreuth; 95440 Bayreuth Germany
| | - Oliver Schmidt
- Department of Ecological Microbiology; University of Bayreuth; 95440 Bayreuth Germany
| | - Anita S. Gößner
- Department of Ecological Microbiology; University of Bayreuth; 95440 Bayreuth Germany
| | - Harold L. Drake
- Department of Ecological Microbiology; University of Bayreuth; 95440 Bayreuth Germany
| |
Collapse
|
14
|
Performance evaluation of dominance-based and indicator-based multiobjective approaches for phylogenetic inference. Inf Sci (N Y) 2016. [DOI: 10.1016/j.ins.2015.10.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
15
|
Ufarté L, Potocki-Veronese G, Laville É. Discovery of new protein families and functions: new challenges in functional metagenomics for biotechnologies and microbial ecology. Front Microbiol 2015; 6:563. [PMID: 26097471 PMCID: PMC4456863 DOI: 10.3389/fmicb.2015.00563] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 05/21/2015] [Indexed: 12/30/2022] Open
Abstract
The rapid expansion of new sequencing technologies has enabled large-scale functional exploration of numerous microbial ecosystems, by establishing catalogs of functional genes and by comparing their prevalence in various microbiota. However, sequence similarity does not necessarily reflect functional conservation, since just a few modifications in a gene sequence can have a strong impact on the activity and the specificity of the corresponding enzyme or the recognition for a sensor. Similarly, some microorganisms harbor certain identified functions yet do not have the expected related genes in their genome. Finally, there are simply too many protein families whose function is not yet known, even though they are highly abundant in certain ecosystems. In this context, the discovery of new protein functions, using either sequence-based or activity-based approaches, is of crucial importance for the discovery of new enzymes and for improving the quality of annotation in public databases. This paper lists and explores the latest advances in this field, along with the challenges to be addressed, particularly where microfluidic technologies are concerned.
Collapse
Affiliation(s)
- Lisa Ufarté
- Université de Toulouse, Institut National des Sciences Appliquées (INSA), Université Paul Sabatier (UPS), Institut National Polytechnique (INP), Laboratoire d'Ingénierie des Systèmes Biologiques et des Procédés (LISBP) , Toulouse, France ; INRA - UMR792 Ingénierie des Systèmes Biologiques et des Procédés , Toulouse, France ; CNRS, UMR5504 , Toulouse, France
| | - Gabrielle Potocki-Veronese
- Université de Toulouse, Institut National des Sciences Appliquées (INSA), Université Paul Sabatier (UPS), Institut National Polytechnique (INP), Laboratoire d'Ingénierie des Systèmes Biologiques et des Procédés (LISBP) , Toulouse, France ; INRA - UMR792 Ingénierie des Systèmes Biologiques et des Procédés , Toulouse, France ; CNRS, UMR5504 , Toulouse, France
| | - Élisabeth Laville
- Université de Toulouse, Institut National des Sciences Appliquées (INSA), Université Paul Sabatier (UPS), Institut National Polytechnique (INP), Laboratoire d'Ingénierie des Systèmes Biologiques et des Procédés (LISBP) , Toulouse, France ; INRA - UMR792 Ingénierie des Systèmes Biologiques et des Procédés , Toulouse, France ; CNRS, UMR5504 , Toulouse, France
| |
Collapse
|
16
|
Liu JF, Sun XB, Yang GC, Mbadinga SM, Gu JD, Mu BZ. Analysis of microbial communities in the oil reservoir subjected to CO2-flooding by using functional genes as molecular biomarkers for microbial CO2 sequestration. Front Microbiol 2015; 6:236. [PMID: 25873911 PMCID: PMC4379918 DOI: 10.3389/fmicb.2015.00236] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2014] [Accepted: 03/10/2015] [Indexed: 11/13/2022] Open
Abstract
Sequestration of CO2 in oil reservoirs is considered to be one of the feasible options for mitigating atmospheric CO2 building up and also for the in situ potential bioconversion of stored CO2 to methane. However, the information on these functional microbial communities and the impact of CO2 storage on them is hardly available. In this paper a comprehensive molecular survey was performed on microbial communities in production water samples from oil reservoirs experienced CO2-flooding by analysis of functional genes involved in the process, including cbbM, cbbL, fthfs, [FeFe]-hydrogenase, and mcrA. As a comparison, these functional genes in the production water samples from oil reservoir only experienced water-flooding in areas of the same oil bearing bed were also analyzed. It showed that these functional genes were all of rich diversity in these samples, and the functional microbial communities and their diversity were strongly affected by a long-term exposure to injected CO2. More interestingly, microorganisms affiliated with members of the genera Methanothemobacter, Acetobacterium, and Halothiobacillus as well as hydrogen producers in CO2 injected area either increased or remained unchanged in relative abundance compared to that in water-flooded area, which implied that these microorganisms could adapt to CO2 injection and, if so, demonstrated the potential for microbial fixation and conversion of CO2 into methane in subsurface oil reservoirs.
Collapse
Affiliation(s)
- Jin-Feng Liu
- State Key Laboratory of Bioreactor Engineering and Institute of Applied Chemistry, East China University of Science and Technology Shanghai, China
| | - Xiao-Bo Sun
- State Key Laboratory of Bioreactor Engineering and Institute of Applied Chemistry, East China University of Science and Technology Shanghai, China
| | - Guang-Chao Yang
- State Key Laboratory of Bioreactor Engineering and Institute of Applied Chemistry, East China University of Science and Technology Shanghai, China
| | - Serge M Mbadinga
- State Key Laboratory of Bioreactor Engineering and Institute of Applied Chemistry, East China University of Science and Technology Shanghai, China
| | - Ji-Dong Gu
- School of Biological Sciences, University of Hong Kong Hong Kong, China
| | - Bo-Zhong Mu
- State Key Laboratory of Bioreactor Engineering and Institute of Applied Chemistry, East China University of Science and Technology Shanghai, China
| |
Collapse
|
17
|
Baker BJ, Lazar CS, Teske AP, Dick GJ. Genomic resolution of linkages in carbon, nitrogen, and sulfur cycling among widespread estuary sediment bacteria. MICROBIOME 2015; 3:14. [PMID: 25922666 PMCID: PMC4411801 DOI: 10.1186/s40168-015-0077-6] [Citation(s) in RCA: 208] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 03/12/2015] [Indexed: 05/20/2023]
Abstract
BACKGROUND Estuaries are among the most productive habitats on the planet. Bacteria in estuary sediments control the turnover of organic carbon and the cycling of nitrogen and sulfur. These communities are complex and primarily made up of uncultured lineages, thus little is known about how ecological and metabolic processes are partitioned in sediments. RESULTS De novo assembly and binning resulted in the reconstruction of 82 bacterial genomes from different redox regimes of estuary sediments. These genomes belong to 23 bacterial groups, including uncultured candidate phyla (for example, KSB1, TA06, and KD3-62) and three newly described phyla (White Oak River (WOR)-1, WOR-2, and WOR-3). The uncultured phyla are generally most abundant in the sulfate-methane transition (SMTZ) and methane-rich zones, and genomic data predict that they mediate essential biogeochemical processes of the estuarine environment, including organic carbon degradation and fermentation. Among the most abundant organisms in the sulfate-rich layer are novel Gammaproteobacteria that have genes for the oxidation of sulfur and the reduction of nitrate and nitrite. Interestingly, the terminal steps of denitrification (NO3 to N2O and then N2O to N2) are present in distinct bacterial populations. CONCLUSIONS This dataset extends our knowledge of the metabolic potential of several uncultured phyla. Within the sediments, there is redundancy in the genomic potential in different lineages, often distinct phyla, for essential biogeochemical processes. We were able to chart the flow of carbon and nutrients through the multiple geochemical layers of bacterial processing and reveal potential ecological interactions within the communities.
Collapse
Affiliation(s)
- Brett J Baker
- />Department of Marine Science, University of Texas-Austin, Marine Science Institute, 750 Channel View Dr., Port Aransas, TX 78373 USA
- />Department of Earth and Environmental Sciences, University of Michigan, 1100 N. University Ave., Ann Arbor, MI 48109 USA
| | - Cassandre Sara Lazar
- />Department of Marine Sciences, University of North Carolina, Chapel Hill, NC USA
- />Organic Geochemistry Group, MARUM Center for Marine Environmental Sciences, Department of Geosciences, University of Bremen, Bremen, Germany
| | - Andreas P Teske
- />Department of Marine Sciences, University of North Carolina, Chapel Hill, NC USA
| | - Gregory J Dick
- />Department of Earth and Environmental Sciences, University of Michigan, 1100 N. University Ave., Ann Arbor, MI 48109 USA
- />Center for Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI USA
| |
Collapse
|
18
|
Boyd ES, Hamilton TL, Swanson KD, Howells AE, Baxter BK, Meuser JE, Posewitz MC, Peters JW. [FeFe]-hydrogenase abundance and diversity along a vertical redox gradient in Great Salt Lake, USA. Int J Mol Sci 2014; 15:21947-66. [PMID: 25464382 PMCID: PMC4284687 DOI: 10.3390/ijms151221947] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 11/11/2014] [Accepted: 11/13/2014] [Indexed: 11/29/2022] Open
Abstract
The use of [FeFe]-hydrogenase enzymes for the biotechnological production of H2 or other reduced products has been limited by their sensitivity to oxygen (O2). Here, we apply a PCR-directed approach to determine the distribution, abundance, and diversity of hydA gene fragments along co-varying salinity and O2 gradients in a vertical water column of Great Salt Lake (GSL), UT. The distribution of hydA was constrained to water column transects that had high salt and relatively low O2 concentrations. Recovered HydA deduced amino acid sequences were enriched in hydrophilic amino acids relative to HydA from less saline environments. In addition, they harbored interesting variations in the amino acid environment of the complex H-cluster metalloenzyme active site and putative gas transfer channels that may be important for both H2 transfer and O2 susceptibility. A phylogenetic framework was created to infer the accessory cluster composition and quaternary structure of recovered HydA protein sequences based on phylogenetic relationships and the gene contexts of known complete HydA sequences. Numerous recovered HydA are predicted to harbor multiple N- and C-terminal accessory iron-sulfur cluster binding domains and are likely to exist as multisubunit complexes. This study indicates an important role for [FeFe]-hydrogenases in the functioning of the GSL ecosystem and provides new target genes and variants for use in identifying O2 tolerant enzymes for biotechnological applications.
Collapse
Affiliation(s)
- Eric S Boyd
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59717, USA.
| | - Trinity L Hamilton
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA.
| | - Kevin D Swanson
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA.
| | - Alta E Howells
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA.
| | - Bonnie K Baxter
- Department of Biology and the Great Salt Lake Institute, Westminster College, Salt Lake City, UT 84105, USA.
| | - Jonathan E Meuser
- Department of Chemistry and Geochemistry, Colorado School of Mines, Golden, CO 80401, USA.
| | - Matthew C Posewitz
- Department of Chemistry and Geochemistry, Colorado School of Mines, Golden, CO 80401, USA.
| | - John W Peters
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA.
| |
Collapse
|
19
|
Sharma S, Vakhlu J. Metagenomics as advanced screening methods for novel microbial metabolites. Microb Biotechnol 2014. [DOI: 10.1201/b17587-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
|
20
|
Wrighton KC, Castelle CJ, Wilkins MJ, Hug LA, Sharon I, Thomas BC, Handley KM, Mullin SW, Nicora CD, Singh A, Lipton MS, Long PE, Williams KH, Banfield JF. Metabolic interdependencies between phylogenetically novel fermenters and respiratory organisms in an unconfined aquifer. ISME JOURNAL 2014; 8:1452-63. [PMID: 24621521 DOI: 10.1038/ismej.2013.249] [Citation(s) in RCA: 137] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Revised: 11/07/2013] [Accepted: 12/01/2013] [Indexed: 11/09/2022]
Abstract
Fermentation-based metabolism is an important ecosystem function often associated with environments rich in organic carbon, such as wetlands, sewage sludge and the mammalian gut. The diversity of microorganisms and pathways involved in carbon and hydrogen cycling in sediments and aquifers and the impacts of these processes on other biogeochemical cycles remain poorly understood. Here we used metagenomics and proteomics to characterize microbial communities sampled from an aquifer adjacent to the Colorado River at Rifle, CO, USA, and document interlinked microbial roles in geochemical cycling. The organic carbon content in the aquifer was elevated via acetate amendment of the groundwater occurring over 2 successive years. Samples were collected at three time points, with the objective of extensive genome recovery to enable metabolic reconstruction of the community. Fermentative community members include organisms from a new phylum, Melainabacteria, most closely related to Cyanobacteria, phylogenetically novel members of the Chloroflexi and Bacteroidales, as well as candidate phyla genomes (OD1, BD1-5, SR1, WWE3, ACD58, TM6, PER and OP11). These organisms have the capacity to produce hydrogen, acetate, formate, ethanol, butyrate and lactate, activities supported by proteomic data. The diversity and expression of hydrogenases suggests the importance of hydrogen metabolism in the subsurface. Our proteogenomic data further indicate the consumption of fermentation intermediates by Proteobacteria can be coupled to nitrate, sulfate and iron reduction. Thus, fermentation carried out by previously unknown members of sediment microbial communities may be an important driver of nitrogen, hydrogen, sulfur, carbon and iron cycling.
Collapse
Affiliation(s)
- Kelly C Wrighton
- Department of Microbiology, The Ohio State University, Columbus, OH, USA
| | - Cindy J Castelle
- Department of Earth and Planetary Science, University of California, Berkeley, Berkeley, CA, USA
| | - Michael J Wilkins
- 1] Department of Microbiology, The Ohio State University, Columbus, OH, USA [2] School of Earth Sciences, The Ohio State University, Columbus, OH, USA
| | - Laura A Hug
- Department of Earth and Planetary Science, University of California, Berkeley, Berkeley, CA, USA
| | - Itai Sharon
- Department of Earth and Planetary Science, University of California, Berkeley, Berkeley, CA, USA
| | - Brian C Thomas
- Department of Earth and Planetary Science, University of California, Berkeley, Berkeley, CA, USA
| | - Kim M Handley
- Department of Ecology and Evolution, University of Chicago, Chicago, IL, USA
| | - Sean W Mullin
- Department of Earth and Planetary Science, University of California, Berkeley, Berkeley, CA, USA
| | - Carrie D Nicora
- Pacific Northwest National Laboratory, Department of Energy, Biological Sciences Department, Richland, WA, USA
| | - Andrea Singh
- Department of Earth and Planetary Science, University of California, Berkeley, Berkeley, CA, USA
| | - Mary S Lipton
- Pacific Northwest National Laboratory, Department of Energy, Biological Sciences Department, Richland, WA, USA
| | - Philip E Long
- Lawrence Berkeley National Laboratory, Department of Energy, Berkeley, CA, USA
| | - Kenneth H Williams
- Lawrence Berkeley National Laboratory, Department of Energy, Berkeley, CA, USA
| | - Jillian F Banfield
- 1] Department of Earth and Planetary Science, University of California, Berkeley, Berkeley, CA, USA [2] Pacific Northwest National Laboratory, Department of Energy, Biological Sciences Department, Richland, WA, USA
| |
Collapse
|
21
|
Baba R, Kimura M, Asakawa S, Watanabe T. Analysis of [FeFe]-hydrogenase genes for the elucidation of a hydrogen-producing bacterial community in paddy field soil. FEMS Microbiol Lett 2013; 350:249-56. [PMID: 24261851 DOI: 10.1111/1574-6968.12335] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2013] [Revised: 09/03/2013] [Accepted: 11/12/2013] [Indexed: 12/01/2022] Open
Abstract
Hydrogen (H2) is one of the most important intermediates in the anaerobic decomposition of organic matter. Although the microorganisms consuming H2 in anaerobic environments have been well documented, those producing H2 are not well known. In this study, we elucidated potential members of H2 -producing bacteria in a paddy field soil using clone library analysis of [FeFe]-hydrogenase genes. The [FeFe]-hydrogenase is an enzyme involved in H2 metabolism, especially in H2 production. A suitable primer set was selected based on the preliminary clone library analysis performed using three primer sets designed for the [FeFe]-hydrogenase genes. Soil collected in flooded and drained periods was used to examine the dominant [FeFe]-hydrogenase genes in the paddy soil bacteria. In total, 115 and 108 clones were analyzed from the flooded and drained paddy field soils, respectively. Homology and phylogenetic analysis of the clones showed the presence of diverse [FeFe]-hydrogenase genes mainly related to Firmicutes, Deltaproteobacteria, and Chloroflexi. Predominance of Deltaproteobacteria and Chloroflexi suggests that the distinct bacterial community possessed [FeFe]-hydrogenase genes in the paddy field soil. Our study revealed the potential members of H2 -producing bacteria in the paddy field soil based on their genetic diversity and the distinctiveness of the [FeFe]-hydrogenase genes.
Collapse
Affiliation(s)
- Ryuko Baba
- Laboratory of Soil Biology and Chemistry, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, Japan
| | | | | | | |
Collapse
|
22
|
Santander-Jiménez S, Vega-Rodríguez MA. Applying a multiobjective metaheuristic inspired by honey bees to phylogenetic inference. Biosystems 2013; 114:39-55. [DOI: 10.1016/j.biosystems.2013.07.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 06/17/2013] [Accepted: 07/02/2013] [Indexed: 10/26/2022]
|
23
|
Tomazetto G, Oliveira VM. Investigation of the FeFe-hydrogenase gene diversity combined with phylogenetic microbial community analysis of an anaerobic domestic sewage sludge. World J Microbiol Biotechnol 2013; 29:2003-14. [PMID: 23632909 DOI: 10.1007/s11274-013-1363-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Accepted: 04/24/2013] [Indexed: 10/26/2022]
Abstract
Biological hydrogen production through the anaerobic digestion is an environmental friendly alternative for satisfying future hydrogen demands. Microorganisms residing into waste water treatment plants are far from being exhaustively characterized and surveys on hydrogen production through FeFe-hydrogenase in such ecosystems are scarce. This study combined the analysis of 16S rRNA and [FeFe]-hydrogenase (hydA) genes with statistical tools to estimate richness and diversity of the microbial community of a domestic sewage treatment plant at the phylogenetic and functional levels. Archaeal groups were represented by 69 % of sequences assigned to Methanosarcinales and the remaining belonged to Methanomicrobiales. Within the bacterial library, 136 operational taxonomic units (OTUs) were distributed into 9 phyla, being 86 OTUs related to uncultivated bacteria. From these, 25 OTUs represented potential novel taxa within Synergistetes. Proteobacteria was the most predominant (36 % of the OTUs) and diversified phylogenetic group in the bacterial library, most of them assigned to the class Betaproteobacteria. Twenty-two putative hydA sequences were recovered into four distinct clusters and most of them were more closely related to each other than with sequences retrieved from databases, indicating they are hitherto undetected [Fe-Fe]-hydrogenase gene sequences. The richness estimates revealed that the number of sampled sequences was enough for full coverage of the archaeal diversity but not sufficient to cover both bacterial and hydA gene diversities. The results confirmed a great richness and diversity of bacterial and hydA sequences retrieved from the sewage sludge sample, suggesting such environment as a potential reservoir of new hydrogenase genes for biotechnological exploration.
Collapse
Affiliation(s)
- Geizecler Tomazetto
- Division of Microbial Resources, Research Center for Chemistry, Biology and Agriculture (CPQBA), Campinas University (UNICAMP), CP 6171, Campinas, SP, CEP 13081-970, Brazil ,
| | | |
Collapse
|
24
|
Hydrogen-producing microflora and Fe-Fe hydrogenase diversities in seaweed bed associated with marine hot springs of Kalianda, Indonesia. Curr Microbiol 2013; 66:499-506. [PMID: 23325032 DOI: 10.1007/s00284-013-0302-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Accepted: 12/18/2012] [Indexed: 10/27/2022]
Abstract
Microbial fermentation is a promising technology for hydrogen (H(2)) production. H(2) producers in marine geothermal environments are thermophilic and halotolerant. However, no one has surveyed an environment specifically for thermophilic bacteria that produce H(2) through Fe-Fe hydrogenases (H(2)ase). Using heterotrophic medium, several microflora from a seaweed bed associated with marine hot springs were enriched and analyzed for H(2) production. A H(2)-producing microflora was obtained from Sargassum sp., 16S rRNA genes and Fe-Fe H(2)ase diversities of this enrichment were also analyzed. Based on 16S rRNA genes analysis, 10 phylotypes were found in the H(2)-producing microflora showing 90.0-99.5 % identities to known species, and belonged to Clostridia, Gammaproteobacteria, and Bacillales. Clostridia were the most abundant group, and three Clostridia phylotypes were most related to known H(2) producers such as Anaerovorax odorimutans (94.0 % identity), Clostridium papyrosolvens (98.4 % identity), and Clostridium tepidiprofundi (93.1 % identity). For Fe-Fe H(2)ases, seven phylotypes were obtained, showing 63-97 % identities to known Fe-Fe H(2)ases, and fell into four distinct clusters. Phylotypes HW55-3 and HM55-1 belonged to thermophilic and salt-tolerant H(2)-producing Clostridia, Halothermothrix orenii-like Fe-Fe H(2)ases (80 % identity), and cellulolytic H(2)-producing Clostridia, C. papyrosolvens-like Fe-Fe H(2)ases (97 % identity), respectively. The results of both 16S rRNA genes and Fe-Fe H(2)ases surveys suggested that the thermophilic and halotolerant H(2)-producing microflora in seaweed bed of hot spring area represented previously unknown H(2) producers, and have potential application for H(2) production.
Collapse
|
25
|
Chow J, Kovacic F, Dall Antonia Y, Krauss U, Fersini F, Schmeisser C, Lauinger B, Bongen P, Pietruszka J, Schmidt M, Menyes I, Bornscheuer UT, Eckstein M, Thum O, Liese A, Mueller-Dieckmann J, Jaeger KE, Streit WR. The metagenome-derived enzymes LipS and LipT increase the diversity of known lipases. PLoS One 2012; 7:e47665. [PMID: 23112831 PMCID: PMC3480424 DOI: 10.1371/journal.pone.0047665] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Accepted: 09/13/2012] [Indexed: 11/18/2022] Open
Abstract
Triacylglycerol lipases (EC 3.1.1.3) catalyze both hydrolysis and synthesis reactions with a broad spectrum of substrates rendering them especially suitable for many biotechnological applications. Most lipases used today originate from mesophilic organisms and are susceptible to thermal denaturation whereas only few possess high thermotolerance. Here, we report on the identification and characterization of two novel thermostable bacterial lipases identified by functional metagenomic screenings. Metagenomic libraries were constructed from enrichment cultures maintained at 65 to 75 °C and screened resulting in the identification of initially 10 clones with lipolytic activities. Subsequently, two ORFs were identified encoding lipases, LipS and LipT. Comparative sequence analyses suggested that both enzymes are members of novel lipase families. LipS is a 30.2 kDa protein and revealed a half-life of 48 h at 70 °C. The lipT gene encoded for a multimeric enzyme with a half-life of 3 h at 70 °C. LipS had an optimum temperature at 70 °C and LipT at 75 °C. Both enzymes catalyzed hydrolysis of long-chain (C(12) and C(14)) fatty acid esters and additionally hydrolyzed a number of industry-relevant substrates. LipS was highly specific for (R)-ibuprofen-phenyl ester with an enantiomeric excess (ee) of 99%. Furthermore, LipS was able to synthesize 1-propyl laurate and 1-tetradecyl myristate at 70 °C with rates similar to those of the lipase CalB from Candida antarctica. LipS represents the first example of a thermostable metagenome-derived lipase with significant synthesis activities. Its X-ray structure was solved with a resolution of 1.99 Å revealing an unusually compact lid structure.
Collapse
Affiliation(s)
- Jennifer Chow
- Department of Microbiology and Biotechnology, Biocenter Klein Flottbek, University of Hamburg, Hamburg, Germany
| | - Filip Kovacic
- Institute of Molecular Enzyme Technology, Heinrich Heine University Duesseldorf, Research Center Juelich, Juelich, Germany
| | - Yuliya Dall Antonia
- European Molecular Biology Laboratory (EMBL) Hamburg Outstation, c/o Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany
| | - Ulrich Krauss
- Institute of Molecular Enzyme Technology, Heinrich Heine University Duesseldorf, Research Center Juelich, Juelich, Germany
| | - Francesco Fersini
- European Molecular Biology Laboratory (EMBL) Hamburg Outstation, c/o Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany
| | - Christel Schmeisser
- Department of Microbiology and Biotechnology, Biocenter Klein Flottbek, University of Hamburg, Hamburg, Germany
| | - Benjamin Lauinger
- Institute of Bioorganic Chemistry, Heinrich Heine University Duesseldorf, Research Center Juelich, Juelich, Germany
| | - Patrick Bongen
- Institute of Bioorganic Chemistry, Heinrich Heine University Duesseldorf, Research Center Juelich, Juelich, Germany
| | - Joerg Pietruszka
- Institute of Bioorganic Chemistry, Heinrich Heine University Duesseldorf, Research Center Juelich, Juelich, Germany
| | - Marlen Schmidt
- Department of Biotechnology & Enzyme Catalysis, Institute of Biochemistry, Greifswald University, Greifswald, Germany
| | - Ina Menyes
- Department of Biotechnology & Enzyme Catalysis, Institute of Biochemistry, Greifswald University, Greifswald, Germany
| | - Uwe T. Bornscheuer
- Department of Biotechnology & Enzyme Catalysis, Institute of Biochemistry, Greifswald University, Greifswald, Germany
| | - Marrit Eckstein
- Bioprocess Development Consumer Specialties and Biocatalysis Biotechnology, Evonik Industries AG, Essen, Germany
| | - Oliver Thum
- Bioprocess Development Consumer Specialties and Biocatalysis Biotechnology, Evonik Industries AG, Essen, Germany
| | - Andreas Liese
- Institute of Technical Biocatalysis, Hamburg University of Technology, Hamburg, Germany
| | - Jochen Mueller-Dieckmann
- European Molecular Biology Laboratory (EMBL) Hamburg Outstation, c/o Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany
| | - Karl-Erich Jaeger
- Institute of Molecular Enzyme Technology, Heinrich Heine University Duesseldorf, Research Center Juelich, Juelich, Germany
| | - Wolfgang R. Streit
- Department of Microbiology and Biotechnology, Biocenter Klein Flottbek, University of Hamburg, Hamburg, Germany
| |
Collapse
|
26
|
Abstract
Colonic gases are among the most tangible features of digestion, yet physicians are typically unable to offer long-term relief from clinical complaints of excessive gas. Studies characterizing colonic gases have linked changes in volume or composition with bowel disorders and shown hydrogen gas (H(2)), methane, hydrogen sulphide, and carbon dioxide to be by-products of the interplay between H(2)-producing fermentative bacteria and H(2) consumers (reductive acetogens, methanogenic archaea and sulphate-reducing bacteria [SRB]). Clinically, H(2) and methane measured in breath can indicate lactose and glucose intolerance, small intestinal bacterial overgrowth and IBS. Methane levels are increased in patients with constipation or IBS. Hydrogen sulphide is a by-product of H(2) metabolism by SRB, which are ubiquitous in the colonic mucosa. Although higher hydrogen sulphide and SRB levels have been detected in patients with IBD, and to a lesser extent in colorectal cancer, this colonic gas might have beneficial effects. Moreover, H(2) has been shown to have antioxidant properties and, in the healthy colon, physiological H(2) concentrations might protect the mucosa from oxidative insults, whereas an impaired H(2) economy might facilitate inflammation or carcinogenesis. Therefore, standardized breath gas measurements combined with ever-improving molecular methodologies could provide novel strategies to prevent, diagnose or manage numerous colonic disorders.
Collapse
|
27
|
Wu CW, Whang LM, Cheng HH, Chan KC. Fermentative biohydrogen production from lactate and acetate. BIORESOURCE TECHNOLOGY 2012; 113:30-6. [PMID: 22318084 DOI: 10.1016/j.biortech.2011.12.130] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2011] [Revised: 12/25/2011] [Accepted: 12/26/2011] [Indexed: 05/15/2023]
Abstract
In this study, a continuous-flow stirred tank reactor (CSTR) fed with lactate and acetate was operated to enrich hydrogen-producing bacteria. By varying the influent substrate concentrations and hydraulic retention times (HRT), the volumetric loading rate (VLR) of 55.64 kg-COD/m(3)/day seemed to be optimum for this enriched culture for fermentative hydrogen production from lactate and acetate. The results of batch experiments confirmed that the enriched culture tended to fulfill the e(-) equiv requirement for cell growth at a lower VLR condition (21.77 kg-COD/m(3)/day), while it could largely distribute the e(-) equiv for hydrogen production at a higher VLR condition. However, a maximum lactate/acetate concentration allowed for enriching this culture existed, especially at a lower HRT condition in which wash-out can be an issue for this enriched culture. Finally, the results of cloning and sequencing indicated that Clostridium tyrobutyricum was considered the major hydrogen-producing bacteria in the CSTR fed with lactate and acetate.
Collapse
Affiliation(s)
- Chao-Wei Wu
- Department of Environmental Engineering, National Cheng Kung University, No. 1, University Road, Tainan 701, Taiwan
| | | | | | | |
Collapse
|
28
|
Cheng HH, Whang LM, Wu CW, Chung MC. A two-stage bioprocess for hydrogen and methane production from rice straw bioethanol residues. BIORESOURCE TECHNOLOGY 2012; 113:23-29. [PMID: 22290020 DOI: 10.1016/j.biortech.2011.12.103] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2011] [Revised: 12/20/2011] [Accepted: 12/20/2011] [Indexed: 05/31/2023]
Abstract
This study evaluates a two-stage bioprocess for recovering hydrogen and methane while treating organic residues of fermentative bioethanol from rice straw. The obtained results indicate that controlling a proper volumetric loading rate, substrate-to-biomass ratio, or F/M ratio is important to maximizing biohydrogen production from rice straw bioethanol residues. Clostridium tyrobutyricum, the identified major hydrogen-producing bacteria enriched in the hydrogen bioreactor, is likely utilizing lactate and acetate for biohydrogen production. The occurrence of acetogenesis during biohydrogen fermentation may reduce the B/A ratio and lead to a lower hydrogen production. Organic residues remained in the effluent of hydrogen bioreactor can be effectively converted to methane with a rate of 2.8 mmol CH(4)/gVSS/h at VLR of 4.6 kg COD/m(3)/d. Finally, approximately 75% of COD in rice straw bioethanol residues can be removed and among that 1.3% and 66.1% of COD can be recovered in the forms of hydrogen and methane, respectively.
Collapse
Affiliation(s)
- Hai-Hsuan Cheng
- Department of Environmental Engineering, National Cheng Kung University, No. 1, University Road, Tainan 701, Taiwan
| | | | | | | |
Collapse
|
29
|
Brazelton WJ, Nelson B, Schrenk MO. Metagenomic evidence for h(2) oxidation and h(2) production by serpentinite-hosted subsurface microbial communities. Front Microbiol 2012; 2:268. [PMID: 22232619 PMCID: PMC3252642 DOI: 10.3389/fmicb.2011.00268] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Accepted: 12/16/2011] [Indexed: 12/03/2022] Open
Abstract
Ultramafic rocks in the Earth’s mantle represent a tremendous reservoir of carbon and reducing power. Upon tectonic uplift and exposure to fluid flow, serpentinization of these materials generates copious energy, sustains abiogenic synthesis of organic molecules, and releases hydrogen gas (H2). In order to assess the potential for microbial H2 utilization fueled by serpentinization, we conducted metagenomic surveys of a marine serpentinite-hosted hydrothermal chimney (at the Lost City hydrothermal field) and two continental serpentinite-hosted alkaline seeps (at the Tablelands Ophiolite, Newfoundland). Novel [NiFe]-hydrogenase sequences were identified at both the marine and continental sites, and in both cases, phylogenetic analyses indicated aerobic, potentially autotrophic Betaproteobacteria belonging to order Burkholderiales as the most likely H2-oxidizers. Both sites also yielded metagenomic evidence for microbial H2 production catalyzed by [FeFe]-hydrogenases in anaerobic Gram-positive bacteria belonging to order Clostridiales. In addition, we present metagenomic evidence at both sites for aerobic carbon monoxide utilization and anaerobic carbon fixation via the Wood–Ljungdahl pathway. In general, our results point to H2-oxidizing Betaproteobacteria thriving in shallow, oxic–anoxic transition zones and the anaerobic Clostridia thriving in anoxic, deep subsurface habitats. These data demonstrate the feasibility of metagenomic investigations into novel subsurface habitats via surface-exposed seeps and indicate the potential for H2-powered primary production in serpentinite-hosted subsurface habitats.
Collapse
|
30
|
Contrasting denitrifier communities relate to contrasting N2O emission patterns from acidic peat soils in arctic tundra. ISME JOURNAL 2011; 6:1058-77. [PMID: 22134649 DOI: 10.1038/ismej.2011.172] [Citation(s) in RCA: 123] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Cryoturbated peat circles (that is, bare surface soil mixed by frost action; pH 3-4) in the Russian discontinuous permafrost tundra are nitrate-rich 'hotspots' of nitrous oxide (N(2)O) emissions in arctic ecosystems, whereas adjacent unturbated peat areas are not. N(2)O was produced and subsequently consumed at pH 4 in unsupplemented anoxic microcosms with cryoturbated but not in those with unturbated peat soil. Nitrate, nitrite and acetylene stimulated net N(2)O production of both soils in anoxic microcosms, indicating denitrification as the source of N(2)O. Up to 500 and 10 μM nitrate stimulated denitrification in cryoturbated and unturbated peat soils, respectively. Apparent maximal reaction velocities of nitrite-dependent denitrification were 28 and 18 nmol N(2)O g(DW)(-1) h(-1), for cryoturbated and unturbated peat soils, respectively. Barcoded amplicon pyrosequencing of narG, nirK/nirS and nosZ (encoding nitrate, nitrite and N(2)O reductases, respectively) yielded ≈49 000 quality-filtered sequences with an average sequence length of 444 bp. Up to 19 species-level operational taxonomic units were detected per soil and gene, many of which were distantly related to cultured denitrifiers or environmental sequences. Denitrification-associated gene diversity in cryoturbated and in unturbated peat soils differed. Quantitative PCR (inhibition-corrected per DNA extract) revealed higher copy numbers of narG in cryoturbated than in unturbated peat soil. Copy numbers of nirS were up to 1000 × higher than those of nirK in both soils, and nirS nirK(-1) copy number ratios in cryoturbated and unturbated peat soils differed. The collective data indicate that the contrasting N(2)O emission patterns of cryoturbated and unturbated peat soils are associated with contrasting denitrifier communities.
Collapse
|
31
|
Calusinska M, Joris B, Wilmotte A. Genetic diversity and amplification of different clostridial [FeFe] hydrogenases by group-specific degenerate primers. Lett Appl Microbiol 2011; 53:473-80. [PMID: 21838748 DOI: 10.1111/j.1472-765x.2011.03135.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIMS The aim of this study was to explore and characterize the genetic diversity of [FeFe] hydrogenases in a representative set of strains from Clostridium sp. and to reveal the existence of neither yet detected nor characterized [FeFe] hydrogenases in hydrogen-producing strains. METHODS AND RESULTS The genomes of 57 Clostridium strains (34 different genotypic species), representing six phylogenetic clusters based on their 16S rRNA sequence analysis (cluster I, III, XIa, XIb, XIV and XVIII), were screened for different [FeFe] hydrogenases. Based on the obtained alignments, ten pairs of [FeFe] hydrogenase cluster-specific degenerate primers were newly designed. Ten Clostridium strains were screened by PCRs to assess the specificity of the primers designed and to examine the genetic diversity of [FeFe] hydrogenases. Using this approach, a diversity of hydrogenase genes was discovered in several species previously shown to produce hydrogen in bioreactors: Clostridium sartagoforme, Clostridium felsineum, Clostridium roseum and Clostridium pasteurianum. CONCLUSIONS The newly designed [FeFe] hydrogenase cluster-specific primers, targeting the cluster-conserved regions, allow for a direct amplification of a specific hydrogenase gene from the species of interest. SIGNIFICANCE AND IMPACT OF THE STUDY Using this strategy for a screening of different Clostridium ssp. will provide new insights into the diversity of hydrogenase genes and should be a first step to study a complex hydrogen metabolism of this genus.
Collapse
Affiliation(s)
- M Calusinska
- Centre for Protein Engineering, Bacterial Physiology and Genetics, University of Liège, Liège, Belgium.
| | | | | |
Collapse
|
32
|
Novel [NiFe]- and [FeFe]-hydrogenase gene transcripts indicative of active facultative aerobes and obligate anaerobes in earthworm gut contents. Appl Environ Microbiol 2011; 77:5842-50. [PMID: 21784904 DOI: 10.1128/aem.05432-11] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The concomitant occurrence of molecular hydrogen (H(2)) and organic acids along the alimentary canal of the earthworm is indicative of ongoing fermentation during gut passage. Fermentative H(2) production is catalyzed by [FeFe]-hydrogenases and group 4 [NiFe]-hydrogenases in obligate anaerobes (e.g., Clostridiales) and facultative aerobes (e.g., Enterobacteriaceae), respectively, functional groups that might respond differently to contrasting redox conditions. Thus, the objectives of this study were to assess the redox potentials of the alimentary canal of Lumbricus terrestris and analyze the hydrogenase transcript diversities of H(2) producers in glucose-supplemented gut content microcosms. Although redox potentials in the core of the alimentary canal were variable on an individual worm basis, average redox potentials were similar. The lowest redox potentials occurred in the foregut and midgut regions, averaging 40 and 110 mV, respectively. Correlation plots between hydrogenase amino acid sequences and 16S rRNA gene sequences indicated that closely related hydrogenases belonged to closely related taxa, whereas distantly related hydrogenases did not necessarily belong to distantly related taxa. Of 178 [FeFe]-hydrogenase gene transcripts, 177 clustered in 12 Clostridiales-affiliated operational taxonomic units, the majority of which were indicative of heretofore unknown hydrogenases. Of 86 group 4 [NiFe]-hydrogenase gene transcripts, 79% and 21% were affiliated with organisms in the Enterobacteriaceae and Aeromonadaceae, respectively. The collective results (i) suggest that fermenters must cope with variable and moderately oxidative redox conditions along the alimentary canal, (ii) demonstrate that heretofore undetected hydrogenases are present in the earthworm gut, and (iii) corroborate previous findings implicating Clostridiaceae and Enterobacteriaceae as active fermentative taxa in earthworm gut content.
Collapse
|
33
|
Abstract
Metagenomics has revolutionized microbiology by paving the way for a cultivation-independent assessment and exploitation of microbial communities present in complex ecosystems. Metagenomics comprising construction and screening of metagenomic DNA libraries has proven to be a powerful tool to isolate new enzymes and drugs of industrial importance. So far, the majority of the metagenomically exploited habitats comprised temperate environments, such as soil and marine environments. Recently, metagenomes of extreme environments have also been used as sources of novel biocatalysts. The employment of next-generation sequencing techniques for metagenomics resulted in the generation of large sequence data sets derived from various environments, such as soil, the human body, and ocean water. Analyses of these data sets opened a window into the enormous taxonomic and functional diversity of environmental microbial communities. To assess the functional dynamics of microbial communities, metatranscriptomics and metaproteomics have been developed. The combination of DNA-based, mRNA-based, and protein-based analyses of microbial communities present in different environments is a way to elucidate the compositions, functions, and interactions of microbial communities and to link these to environmental processes.
Collapse
|
34
|
Global gene expression patterns in Clostridium thermocellum as determined by microarray analysis of chemostat cultures on cellulose or cellobiose. Appl Environ Microbiol 2010; 77:1243-53. [PMID: 21169455 DOI: 10.1128/aem.02008-10] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
A microarray study of chemostat growth on insoluble cellulose or soluble cellobiose has provided substantial new information on Clostridium thermocellum gene expression. This is the first comprehensive examination of gene expression in C. thermocellum under defined growth conditions. Expression was detected from 2,846 of 3,189 genes, and regression analysis revealed 348 genes whose changes in expression patterns were growth rate and/or substrate dependent. Successfully modeled genes included those for scaffoldin and cellulosomal enzymes, intracellular metabolic enzymes, transcriptional regulators, sigma factors, signal transducers, transporters, and hypothetical proteins. Unique genes encoding glycolytic pathway and ethanol fermentation enzymes expressed at high levels simultaneously with previously established maximal ethanol production were also identified. Ranking of normalized expression intensities revealed significant changes in transcriptional levels of these genes. The pattern of expression of transcriptional regulators, sigma factors, and signal transducers indicates that response to growth rate is the dominant global mechanism used for control of gene expression in C. thermocellum.
Collapse
|
35
|
Abstract
Metagenomics has revolutionized microbiology by paving the way for a cultivation-independent assessment and exploitation of microbial communities present in complex ecosystems. Metagenomics comprising construction and screening of metagenomic DNA libraries has proven to be a powerful tool to isolate new enzymes and drugs of industrial importance. So far, the majority of the metagenomically exploited habitats comprised temperate environments, such as soil and marine environments. Recently, metagenomes of extreme environments have also been used as sources of novel biocatalysts. The employment of next-generation sequencing techniques for metagenomics resulted in the generation of large sequence data sets derived from various environments, such as soil, the human body, and ocean water. Analyses of these data sets opened a window into the enormous taxonomic and functional diversity of environmental microbial communities. To assess the functional dynamics of microbial communities, metatranscriptomics and metaproteomics have been developed. The combination of DNA-based, mRNA-based, and protein-based analyses of microbial communities present in different environments is a way to elucidate the compositions, functions, and interactions of microbial communities and to link these to environmental processes.
Collapse
|