1
|
Ma Y, Qu Y, Yao X, Xia C, Lv M, Lin X, Zhang L, Zhang M, Hu B. Unveiling the unique role of iron in the metabolism of methanogens: A review. ENVIRONMENTAL RESEARCH 2024; 250:118495. [PMID: 38367837 DOI: 10.1016/j.envres.2024.118495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 02/06/2024] [Accepted: 02/13/2024] [Indexed: 02/19/2024]
Abstract
Methanogens are the main participants in the carbon cycle, catalyzing five methanogenic pathways. Methanogens utilize different iron-containing functional enzymes in different methanogenic processes. Iron is a vital element in methanogens, which can serve as a carrier or reactant in electron transfer. Therefore, iron plays an important role in the growth and metabolism of methanogens. In this paper, we cast light on the types and functions of iron-containing functional enzymes involved in different methanogenic pathways, and the roles iron play in energy/substance metabolism of methanogenesis. Furthermore, this review provides certain guiding significance for lowering CH4 emissions, boosting the carbon sink capacity of ecosystems and promoting green and low-carbon development in the future.
Collapse
Affiliation(s)
- Yuxin Ma
- Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, College of Environmental Resource Sciences, Zhejiang University, Hangzhou, Zhejiang, China; Department of Environmental Engineering, Zhejiang University, Hangzhou, Zhejiang, China
| | - Ying Qu
- Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, College of Environmental Resource Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Xiangwu Yao
- Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, College of Environmental Resource Sciences, Zhejiang University, Hangzhou, Zhejiang, China; Zhejiang Province Key Laboratory for Water Pollution Control and Environmental Safety, Hangzhou, Zhejiang, China; Department of Environmental Engineering, Zhejiang University, Hangzhou, Zhejiang, China
| | - Chujun Xia
- Department of Environmental Engineering, Zhejiang University, Hangzhou, Zhejiang, China
| | - Mengjie Lv
- Department of Environmental Engineering, Zhejiang University, Hangzhou, Zhejiang, China
| | - Xiao Lin
- Department of Environmental Engineering, Zhejiang University, Hangzhou, Zhejiang, China
| | - Lili Zhang
- Beijing Enterprises Water Group Limited, Beijing, China
| | - Meng Zhang
- Zhejiang Province Key Laboratory for Water Pollution Control and Environmental Safety, Hangzhou, Zhejiang, China; Department of Environmental Engineering, Zhejiang University, Hangzhou, Zhejiang, China
| | - Baolan Hu
- Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, College of Environmental Resource Sciences, Zhejiang University, Hangzhou, Zhejiang, China; Zhejiang Province Key Laboratory for Water Pollution Control and Environmental Safety, Hangzhou, Zhejiang, China; Department of Environmental Engineering, Zhejiang University, Hangzhou, Zhejiang, China.
| |
Collapse
|
2
|
Liu H, Cai X, Luo K, Chen S, Su M, Lu J. Microbial Diversity, Community Turnover, and Putative Functions in Submarine Canyon Sediments under the Action of Sedimentary Geology. Microbiol Spectr 2023; 11:e0421022. [PMID: 36802161 PMCID: PMC10100816 DOI: 10.1128/spectrum.04210-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Accepted: 01/31/2023] [Indexed: 02/23/2023] Open
Abstract
Sampling challenges in deep-sea ecosystems lead to a lack of knowledge about the distribution of microbes in different submarine canyons. To study microbial diversity and community turnover under different ecological processes, we performed 16S/18S rRNA gene amplicon sequencing for sediment samples from a submarine canyon in the South China Sea. Bacteria, archaea, and eukaryotes made up 57.94% (62 phyla), 41.04% (12 phyla), and 1.02% (4 phyla) of the sequences, respectively. Thaumarchaeota, Planctomycetota, Proteobacteria, Nanoarchaeota, and Patescibacteria are the five most abundant phyla. Heterogeneous community composition was mainly observed in vertical profiles rather than horizontal geographic locations, and microbial diversity in the surface layer was much lower than that in deep layers. According to the null model tests, homogeneous selection dominated community assembly within each sediment layer, whereas heterogeneous selection and dispersal limitation dominated community assembly between distant layers. Different sedimentation processes of sediments, i.e., rapid deposition caused by turbidity currents or slow sedimentation, seem to be primarily responsible for these vertical variations. Finally, functional annotation through shotgun-metagenomic sequencing found that glycosyl transferases and glycoside hydrolases are the most abundant carbohydrate-active enzyme categories. The most likely expressed sulfur cycling pathways include assimilatory sulfate reduction, the link between inorganic and organic sulfur transformation, and organic sulfur transformation, while the potentially activated methane cycling pathways include aceticlastic methanogenesis and aerobic and anaerobic oxidation of methane. Overall, our study revealed high levels of microbial diversity and putative functions in canyon sediments and the important influence of sedimentary geology on microbial community turnover between vertical sediment layers. IMPORTANCE Deep-sea microbes have received growing attention due to their contribution to biogeochemical cycles and climate change. However, related research lags due to the difficulty of collecting samples. Based on our previous study, which revealed the formation of sediments under the dual action of turbidity currents and seafloor obstacles in a submarine canyon in the South China Sea, this interdisciplinary research provides new insights into how sedimentary geology influences microbial community assembly in sediments. We proposed some uncommon or new findings, including the following: (i) microbial diversity was much lower on the surface than in deeper layers (ii) archaea and bacteria dominated the surface and deep layers, respectively; (iii) sedimentary geology played key roles in vertical community turnover; and (iv) the microbes have great potential to catalyze sulfur, carbon, and methane cycling. This study may lead to extensive discussion of the assembly and function of deep-sea microbial communities in the context of geology.
Collapse
Affiliation(s)
- Hualin Liu
- School of Marine Sciences, Sun Yat-sen University, Zhuhai, China
| | - Xueyu Cai
- School of Marine Sciences, Sun Yat-sen University, Zhuhai, China
| | - Kunwen Luo
- School of Marine Sciences, Sun Yat-sen University, Zhuhai, China
| | - Sihan Chen
- School of Marine Sciences, Sun Yat-sen University, Zhuhai, China
| | - Ming Su
- School of Marine Sciences, Sun Yat-sen University, Zhuhai, China
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, China
- Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, Guangzhou Guangdong, China
| | - Jianguo Lu
- School of Marine Sciences, Sun Yat-sen University, Zhuhai, China
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, China
- Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, Guangzhou Guangdong, China
- Pearl River Estuary Marine Ecosystem Research Station, Ministry of Education, Zhuhai, China
| |
Collapse
|
3
|
Guo LT, Amikura K, Jiang HK, Mukai T, Fu X, Wang YS, O'Donoghue P, Söll D, Tharp JM. Ancestral Archaea Expanded the Genetic Code with Pyrrolysine. J Biol Chem 2022; 298:102521. [PMID: 36152750 DOI: 10.1016/j.jbc.2022.102521] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 09/15/2022] [Accepted: 09/16/2022] [Indexed: 10/31/2022] Open
Abstract
The pyrrolysyl-tRNA synthetase (PylRS) facilitates the co-translational installation of the 22nd amino acid pyrrolysine. Owing to its tolerance for diverse amino acid substrates, and its orthogonality in multiple organisms, PylRS has emerged as a major route to install noncanonical amino acids into proteins in living cells. Recently, a novel class of PylRS enzymes was identified in a subset of methanogenic archaea. Enzymes within this class (ΔPylSn) lack the N-terminal tRNA-binding domain that is widely conserved amongst PylRS enzymes, yet remain highly active and orthogonal in bacteria and eukaryotes. In this study, we use biochemical and in vivo UAG-readthrough assays to characterize the aminoacylation efficiency and substrate spectrum of a ΔPylSn class PylRS from the archaeon Ca. Methanomethylophilus alvus. We show that, compared to the full-length enzyme from Methanosarcina mazei, the Ca. M. alvus PylRS displays reduced aminoacylation efficiency, but an expanded amino acid substrate spectrum. To gain insight into the evolution of ΔPylSn enzymes, we performed molecular phylogeny using 156 PylRS and 105 tRNAPyl sequences from diverse anaerobic archaea and bacteria. This analysis suggests that the PylRS•tRNAPyl pair diverged before the evolution of the three domains of life, placing an early limit on the evolution of the Pyl-decoding trait. Furthermore, our results document the co-evolutionary history of PylRS and tRNAPyl and reveal the emergence of tRNAPyl sequences with unique A73 and U73 discriminator bases. The orthogonality of these tRNAPyl species with the more common G73-containing tRNAPyl will enable future efforts to engineer PylRS systems for further genetic code expansion.
Collapse
Affiliation(s)
- Li-Tao Guo
- Department of Molecular Biophysics & Biochemistry
| | - Kazuaki Amikura
- Department of Molecular Biophysics & Biochemistry; Department of Interdisciplinary Space Science, Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Kanagawa, Japan
| | - Han-Kai Jiang
- Institute of Biological Chemistry; Chemical Biology and Molecular Biophysics Program, Taiwan International Graduate Program, Academia Sinica, Taipei, Taiwan; Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan
| | - Takahito Mukai
- Department of Life Science, College of Science, Rikkyo University, Tokyo, Japan
| | - Xian Fu
- BGI-Shenzhen, Shenzhen, China; Guangdong Provincial Key Laboratory of Genome Read and Write, Shenzhen, China
| | - Yane-Shih Wang
- Institute of Biological Chemistry; Chemical Biology and Molecular Biophysics Program, Taiwan International Graduate Program, Academia Sinica, Taipei, Taiwan; Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan
| | - Patrick O'Donoghue
- Department of Biochemistry, The University of Western Ontario, London, Canada; Department of Chemistry, The University of Western Ontario, London, Canada
| | - Dieter Söll
- Department of Molecular Biophysics & Biochemistry; Department of Chemistry, Yale University, New Haven, CT, USA
| | - Jeffery M Tharp
- Department of Molecular Biophysics & Biochemistry; Department of Chemistry, The University of Western Ontario, London, Canada.
| |
Collapse
|
4
|
Gontijo JB, Paula FS, Venturini AM, Yoshiura CA, Borges CD, Moura JMS, Bohannan BJM, Nüsslein K, Rodrigues JLM, Tsai SM. Not just a methane source: Amazonian floodplain sediments harbour a high diversity of methanotrophs with different metabolic capabilities. Mol Ecol 2021; 30:2560-2572. [PMID: 33817881 DOI: 10.1111/mec.15912] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 03/22/2021] [Accepted: 03/26/2021] [Indexed: 01/03/2023]
Abstract
The Amazonian floodplain forests are dynamic ecosystems of great importance for the regional hydrological and biogeochemical cycles and function as a significant CH4 source contributing to the global carbon balance. Unique geochemical factors may drive the microbial community composition and, consequently, affect CH4 emissions across floodplain areas. Here, we report the in situ composition of CH4 cycling microbial communities in Amazonian floodplain sediments. We considered how abiotic factors may affect the microbial community composition and, more specifically, CH4 cycling groups. We collected sediment samples during wet and dry seasons from three different types of floodplain forests, along with upland forest soil samples, from the Eastern Amazon, Brazil. We used high-resolution sequencing of archaeal and bacterial 16S rRNA genes combined with real-time PCR to quantify Archaea and Bacteria, as well as key functional genes indicative of the presence of methanogenic (mcrA) and methanotrophic (pmoA) microorganisms. Methanogens were found to be present in high abundance in floodplain sediments, and they seem to resist the dramatic environmental changes between flooded and nonflooded conditions. Methanotrophs known to use different pathways to oxidise CH4 were detected, including anaerobic archaeal and bacterial taxa, indicating that a wide metabolic diversity may be harboured in this highly variable environment. The floodplain environmental variability, which is affected by the river origin, drives not only the sediment chemistry but also the composition of the microbial communities. These environmental changes seem also to affect the pools of methanotrophs occupying distinct niches. Understanding these shifts in the methanotrophic communities could improve our comprehension of the CH4 emissions in the region.
Collapse
Affiliation(s)
- Júlia B Gontijo
- Cell and Molecular Biology Laboratory, Center for Nuclear Energy in Agriculture, University of São Paulo, Piracicaba, Brazil
| | - Fabiana S Paula
- Cell and Molecular Biology Laboratory, Center for Nuclear Energy in Agriculture, University of São Paulo, Piracicaba, Brazil.,Department of Biological Oceanography, Oceanographic Institute, University of São Paulo, São Paulo, Brazil
| | - Andressa M Venturini
- Cell and Molecular Biology Laboratory, Center for Nuclear Energy in Agriculture, University of São Paulo, Piracicaba, Brazil
| | - Caio A Yoshiura
- Cell and Molecular Biology Laboratory, Center for Nuclear Energy in Agriculture, University of São Paulo, Piracicaba, Brazil
| | - Clovis D Borges
- Cell and Molecular Biology Laboratory, Center for Nuclear Energy in Agriculture, University of São Paulo, Piracicaba, Brazil
| | - José Mauro S Moura
- Center for Interdisciplinary Formation, Federal University of Western Pará, Santarém, Brazil
| | - Brendan J M Bohannan
- Department of Biology, Institute of Ecology and Evolution, University of Oregon, Eugene, OR, USA
| | - Klaus Nüsslein
- Department of Microbiology, University of Massachusetts, Amherst, MA, USA
| | - Jorge L Mazza Rodrigues
- Department of Land, Air and Water Resources, University of California, Davis, CA, USA.,Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Siu M Tsai
- Cell and Molecular Biology Laboratory, Center for Nuclear Energy in Agriculture, University of São Paulo, Piracicaba, Brazil
| |
Collapse
|
5
|
Abstract
The aminoacyl-tRNA synthetases are an essential and universally distributed family of enzymes that plays a critical role in protein synthesis, pairing tRNAs with their cognate amino acids for decoding mRNAs according to the genetic code. Synthetases help to ensure accurate translation of the genetic code by using both highly accurate cognate substrate recognition and stringent proofreading of noncognate products. While alterations in the quality control mechanisms of synthetases are generally detrimental to cellular viability, recent studies suggest that in some instances such changes facilitate adaption to stress conditions. Beyond their central role in translation, synthetases are also emerging as key players in an increasing number of other cellular processes, with far-reaching consequences in health and disease. The biochemical versatility of the synthetases has also proven pivotal in efforts to expand the genetic code, further emphasizing the wide-ranging roles of the aminoacyl-tRNA synthetase family in synthetic and natural biology.
Collapse
Affiliation(s)
- Miguel Angel Rubio Gomez
- Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA Department of Microbiology, The Ohio State University, Columbus, Ohio 43210, USA
| | - Michael Ibba
- Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA Department of Microbiology, The Ohio State University, Columbus, Ohio 43210, USA
| |
Collapse
|
6
|
An evolving view of methane metabolism in the Archaea. Nat Rev Microbiol 2019; 17:219-232. [DOI: 10.1038/s41579-018-0136-7] [Citation(s) in RCA: 231] [Impact Index Per Article: 46.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 11/26/2018] [Indexed: 11/08/2022]
|
7
|
Braga LPP, Soucy SM, Amgarten DE, da Silva AM, Setubal JC. Bacterial Diversification in the Light of the Interactions with Phages: The Genetic Symbionts and Their Role in Ecological Speciation. Front Ecol Evol 2018. [DOI: 10.3389/fevo.2018.00006] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
|
8
|
Guan Y, Haroon MF, Alam I, Ferry JG, Stingl U. Single-cell genomics reveals pyrrolysine-encoding potential in members of uncultivated archaeal candidate division MSBL1. ENVIRONMENTAL MICROBIOLOGY REPORTS 2017; 9:404-410. [PMID: 28493460 DOI: 10.1111/1758-2229.12545] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 05/04/2017] [Indexed: 06/07/2023]
Abstract
Pyrrolysine (Pyl), the 22nd canonical amino acid, is only decoded and synthesized by a limited number of organisms in the domains Archaea and Bacteria. Pyl is encoded by the amber codon UAG, typically a stop codon. To date, all known Pyl-decoding archaea are able to carry out methylotrophic methanogenesis. The functionality of methylamine methyltransferases, an important component of corrinoid-dependent methyltransfer reactions, depends on the presence of Pyl. Here, we present a putative pyl gene cluster obtained from single-cell genomes of the archaeal Mediterranean Sea Brine Lakes group 1 (MSBL1) from the Red Sea. Functional annotation of the MSBL1 single cell amplified genomes (SAGs) also revealed a complete corrinoid-dependent methyl-transfer pathway suggesting that members of MSBL1 may possibly be capable of synthesizing Pyl and metabolizing methylated amines.
Collapse
Affiliation(s)
- Yue Guan
- King Abdullah University of Science and Technology (KAUST), Red Sea Research Center, Thuwal, 23955-6900, Saudi Arabia
| | - Mohamed F Haroon
- King Abdullah University of Science and Technology (KAUST), Red Sea Research Center, Thuwal, 23955-6900, Saudi Arabia
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Intikhab Alam
- King Abdullah University of Science and Technology (KAUST), Computational Bioscience Research Center, Thuwal, 23955-6900, Saudi Arabia
| | - James G Ferry
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA, 16802, USA
| | - Ulrich Stingl
- King Abdullah University of Science and Technology (KAUST), Red Sea Research Center, Thuwal, 23955-6900, Saudi Arabia
- Department for Microbiology & Cell Science, Fort Lauderdale Research and Education Center, University of Florida/IFAS, Davie, FL, 33314, USA
| |
Collapse
|
9
|
Unique characteristics of the pyrrolysine system in the 7th order of methanogens: implications for the evolution of a genetic code expansion cassette. ARCHAEA-AN INTERNATIONAL MICROBIOLOGICAL JOURNAL 2014; 2014:374146. [PMID: 24669202 PMCID: PMC3941956 DOI: 10.1155/2014/374146] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Accepted: 10/19/2013] [Indexed: 02/06/2023]
Abstract
Pyrrolysine (Pyl), the 22nd proteogenic amino acid, was restricted until recently to few organisms. Its translational use necessitates the presence of enzymes for synthesizing it from lysine, a dedicated amber stop codon suppressor tRNA, and a specific amino-acyl tRNA synthetase. The three genomes of the recently proposed Thermoplasmata-related 7th order of methanogens contain the complete genetic set for Pyl synthesis and its translational use. Here, we have analyzed the genomic features of the Pyl-coding system in these three genomes with those previously known from Bacteria and Archaea and analyzed the phylogeny of each component. This shows unique peculiarities, notably an amber tRNAPyl with an imperfect anticodon stem and a shortened tRNAPyl synthetase. Phylogenetic analysis indicates that a Pyl-coding system was present in the ancestor of the seventh order of methanogens and appears more closely related to Bacteria than to Methanosarcinaceae, suggesting the involvement of lateral gene transfer in the spreading of pyrrolysine between the two prokaryotic domains. We propose that the Pyl-coding system likely emerged once in Archaea, in a hydrogenotrophic and methanol-H2-dependent methylotrophic methanogen. The close relationship between methanogenesis and the Pyl system provides a possible example of expansion of a still evolving genetic code, shaped by metabolic requirements.
Collapse
|
10
|
Liu L, Chen X, Skogerbø G, Zhang P, Chen R, He S, Huang DW. The human microbiome: A hot spot of microbial horizontal gene transfer. Genomics 2012; 100:265-70. [DOI: 10.1016/j.ygeno.2012.07.012] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Revised: 07/06/2012] [Accepted: 07/16/2012] [Indexed: 12/19/2022]
|
11
|
Plugge CM, Zhang W, Scholten JCM, Stams AJM. Metabolic flexibility of sulfate-reducing bacteria. Front Microbiol 2011; 2:81. [PMID: 21734907 PMCID: PMC3119409 DOI: 10.3389/fmicb.2011.00081] [Citation(s) in RCA: 165] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2011] [Accepted: 04/05/2011] [Indexed: 11/13/2022] Open
Abstract
Dissimilatory sulfate-reducing prokaryotes (SRB) are a very diverse group of anaerobic bacteria that are omnipresent in nature and play an imperative role in the global cycling of carbon and sulfur. In anoxic marine sediments sulfate reduction accounts for up to 50% of the entire organic mineralization in coastal and shelf ecosystems where sulfate diffuses several meters deep into the sediment. As a consequence, SRB would be expected in the sulfate-containing upper sediment layers, whereas methanogenic archaea would be expected to succeed in the deeper sulfate-depleted layers of the sediment. Where sediments are high in organic matter, sulfate is depleted at shallow sediment depths, and biogenic methane production will occur. In the absence of sulfate, many SRB ferment organic acids and alcohols, producing hydrogen, acetate, and carbon dioxide, and may even rely on hydrogen- and acetate-scavenging methanogens to convert organic compounds to methane. SRB can establish two different life styles, and these can be termed as sulfidogenic and acetogenic, hydrogenogenic metabolism. The advantage of having different metabolic capabilities is that it raises the chance of survival in environments when electron acceptors become depleted. In marine sediments, SRB and methanogens do not compete but rather complement each other in the degradation of organic matter. Also in freshwater ecosystems with sulfate concentrations of only 10-200 μM, sulfate is consumed efficiently within the top several cm of the sediments. Here, many of the δ-Proteobacteria present have the genetic machinery to perform dissimilatory sulfate reduction, yet they have an acetogenic, hydrogenogenic way of life. In this review we evaluate the physiology and metabolic mode of SRB in relation with their environment.
Collapse
Affiliation(s)
- Caroline M Plugge
- Laboratory of Microbiology, Wageningen University Wageningen, Netherlands
| | | | | | | |
Collapse
|
12
|
Plugge CM, Zhang W, Scholten JCM, Stams AJM. Metabolic flexibility of sulfate-reducing bacteria. Front Microbiol 2011. [PMID: 21734907 DOI: 10.3389/fmicb.2011.00081/bibtex] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/09/2022] Open
Abstract
Dissimilatory sulfate-reducing prokaryotes (SRB) are a very diverse group of anaerobic bacteria that are omnipresent in nature and play an imperative role in the global cycling of carbon and sulfur. In anoxic marine sediments sulfate reduction accounts for up to 50% of the entire organic mineralization in coastal and shelf ecosystems where sulfate diffuses several meters deep into the sediment. As a consequence, SRB would be expected in the sulfate-containing upper sediment layers, whereas methanogenic archaea would be expected to succeed in the deeper sulfate-depleted layers of the sediment. Where sediments are high in organic matter, sulfate is depleted at shallow sediment depths, and biogenic methane production will occur. In the absence of sulfate, many SRB ferment organic acids and alcohols, producing hydrogen, acetate, and carbon dioxide, and may even rely on hydrogen- and acetate-scavenging methanogens to convert organic compounds to methane. SRB can establish two different life styles, and these can be termed as sulfidogenic and acetogenic, hydrogenogenic metabolism. The advantage of having different metabolic capabilities is that it raises the chance of survival in environments when electron acceptors become depleted. In marine sediments, SRB and methanogens do not compete but rather complement each other in the degradation of organic matter. Also in freshwater ecosystems with sulfate concentrations of only 10-200 μM, sulfate is consumed efficiently within the top several cm of the sediments. Here, many of the δ-Proteobacteria present have the genetic machinery to perform dissimilatory sulfate reduction, yet they have an acetogenic, hydrogenogenic way of life. In this review we evaluate the physiology and metabolic mode of SRB in relation with their environment.
Collapse
Affiliation(s)
- Caroline M Plugge
- Laboratory of Microbiology, Wageningen University Wageningen, Netherlands
| | | | | | | |
Collapse
|
13
|
Lobanov AV, Turanov AA, Hatfield DL, Gladyshev VN. Dual functions of codons in the genetic code. Crit Rev Biochem Mol Biol 2010; 45:257-65. [PMID: 20446809 DOI: 10.3109/10409231003786094] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The discovery of the genetic code provided one of the basic foundations of modern molecular biology. Most organisms use the same genetic language, but there are also well-documented variations representing codon reassignments within specific groups of organisms (such as ciliates and yeast) or organelles (such as plastids and mitochondria). In addition, duality in codon function is known in the use of AUG in translation initiation and methionine insertion into internal protein positions as well as in the case of selenocysteine and pyrrolysine insertion (encoded by UGA and UAG, respectively) in competition with translation termination. Ambiguous meaning of CUG in coding for serine and leucine is also known. However, a recent study revealed that codons in any position within the open reading frame can serve a dual function and that a change in codon meaning can be achieved by availability of a specific type of RNA stem-loop structure in the 3'-untranslated region. Thus, duality of codon function is a more widely used feature of the genetic code than previously known, and this observation raises the possibility that additional recoding events and additional novel features have evolved in the genetic code.
Collapse
Affiliation(s)
- Alexey V Lobanov
- Division of Genetics, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | | | | | | |
Collapse
|
14
|
Shapiro JA. Mobile DNA and evolution in the 21st century. Mob DNA 2010; 1:4. [PMID: 20226073 PMCID: PMC2836002 DOI: 10.1186/1759-8753-1-4] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2009] [Accepted: 01/25/2010] [Indexed: 01/05/2023] Open
Abstract
Scientific history has had a profound effect on the theories of evolution. At the beginning of the 21st century, molecular cell biology has revealed a dense structure of information-processing networks that use the genome as an interactive read-write (RW) memory system rather than an organism blueprint. Genome sequencing has documented the importance of mobile DNA activities and major genome restructuring events at key junctures in evolution: exon shuffling, changes in cis-regulatory sites, horizontal transfer, cell fusions and whole genome doublings (WGDs). The natural genetic engineering functions that mediate genome restructuring are activated by multiple stimuli, in particular by events similar to those found in the DNA record: microbial infection and interspecific hybridization leading to the formation of allotetraploids. These molecular genetic discoveries, plus a consideration of how mobile DNA rearrangements increase the efficiency of generating functional genomic novelties, make it possible to formulate a 21st century view of interactive evolutionary processes. This view integrates contemporary knowledge of the molecular basis of genetic change, major genome events in evolution, and stimuli that activate DNA restructuring with classical cytogenetic understanding about the role of hybridization in species diversification.
Collapse
Affiliation(s)
- James A Shapiro
- Department of Biochemistry and Molecular Biology, University of Chicago, Gordon Center for Integrative Science W123B, 929 E 57th Street, Chicago, IL 60637, USA.
| |
Collapse
|
15
|
Kato S, Watanabe K. Ecological and Evolutionary Interactions in Syntrophic Methanogenic Consortia. Microbes Environ 2010; 25:145-51. [DOI: 10.1264/jsme2.me10122] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
| | - Kazuya Watanabe
- Hashimoto Light Energy Conversion Project, ERATO, JST
- Research Center for Advanced Science and Technology, University of Tokyo
| |
Collapse
|