Ecological Aspects of the Distribution of Different Autotrophic CO ₂ Fixation Pathways

Applied and Environmental Microbiology, Год журнала: 2011, Номер 77(6), С. 1925 - 1936

Опубликована: Янв. 8, 2011

Autotrophic CO(2) fixation represents the most important biosynthetic process in biology. Besides well-known Calvin-Benson cycle, five other totally different autotrophic mechanisms are known today. This minireview discusses factors determining their distribution. As will be made clear, observed diversity reflects variety of organisms and ecological niches existing nature.

Язык: Английский

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Evolution of C–H Bond Functionalization from Methane to Methodology

Journal of the American Chemical Society, Год журнала: 2015, Номер 138(1), С. 2 - 24

Опубликована: Ноя. 13, 2015

This Perspective presents the fundamental principles, elementary reactions, initial catalytic systems, and contemporary catalysts that have converted C–H bond functionalization from a curiosity to reality for synthetic chemists. Many classes of reactions involving transition-metal complexes cleave bonds at typically unreactive positions. These coupled with separate or simultaneous process lead products containing new C–C, C–N, C–O bonds. Such were initially studied conversion light alkanes liquid products, but they been used (and commercialized in some cases) most often synthesis more complex structures natural medicinally active compounds, aromatic materials. change direction research is remarkable because must occur an unactivated over functional groups are reactive than toward classical reagents. The scope form C–C install functionality will be presented, potential future utility these discussed.

Язык: Английский

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Microbial Ecology of the Dark Ocean above, at, and below the Seafloor

Microbiology and Molecular Biology Reviews, Год журнала: 2011, Номер 75(2), С. 361 - 422

Опубликована: Июнь 1, 2011

SUMMARY The majority of life on Earth—notably, microbial life—occurs in places that do not receive sunlight, with the habitats oceans being largest these reservoirs. Sunlight penetrates only a few tens to hundreds meters into ocean, resulting large-scale ecosystems function dark. Our knowledge processes dark ocean—the aphotic pelagic sediments, oceanic crust, hydrothermal vents, etc.—has increased substantially recent decades. Studies try decipher activity microorganisms where we cannot easily observe them, are yielding paradigm-shifting discoveries fundamentally changing our understanding role ocean global Earth system and its biogeochemical cycles. New generations researchers experimental tools have emerged, last decade particular, owing dedicated research programs explore biosphere. This review focuses current microbiology outlining salient features various discussing known still unexplored types metabolism their consequences cycling. We also focus patterns diversity communities characteristic different habitats.

Язык: Английский

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Archaea catalyze iron-dependent anaerobic oxidation of methane

Proceedings of the National Academy of Sciences, Год журнала: 2016, Номер 113(45), С. 12792 - 12796

Опубликована: Окт. 24, 2016

Anaerobic oxidation of methane (AOM) is crucial for controlling the emission this potent greenhouse gas to atmosphere. Nitrite-, nitrate-, and sulfate-dependent well-documented, but AOM coupled reduction oxidized metals has so far been demonstrated only in environmental samples. Here, using a freshwater enrichment culture, we show that archaea order Methanosarcinales, related "Candidatus Methanoperedens nitroreducens," couple environmentally relevant forms Fe3+ Mn4+ methane. We obtained an culture these under anaerobic, nitrate-reducing conditions with continuous supply Via batch incubations [13C]methane, soluble ferric iron (Fe3+, as Fe-citrate) nanoparticulate supported methane-oxidizing activity. CO2 ferrous (Fe2+) were produced stoichiometric amounts. Our study connects previous finding iron-dependent microorganisms detected numerous habitats worldwide. Consequently, it enables better understanding interaction between biogeochemical cycles

Язык: Английский

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Pt/Cu single-atom alloys as coke-resistant catalysts for efficient C–H activation

Nature Chemistry, Год журнала: 2018, Номер 10(3), С. 325 - 332

Опубликована: Янв. 8, 2018

Язык: Английский

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Diversity and Habitat Preferences of Cultivated and Uncultivated Aerobic Methanotrophic Bacteria Evaluated Based on pmoA as Molecular Marker

Frontiers in Microbiology, Год журнала: 2015, Номер 6

Опубликована: Дек. 15, 2015

Methane-oxidizing bacteria are characterized by their capability to grow on methane as sole source of carbon and energy. Cultivation-dependent –independent methods have revealed that this functional guild comprises a substantial diversity organisms. In particular the use cultivation-independent targeting subunit particulate monooxygenase (pmoA) marker for detection aerobic methanotrophs has resulted in thousands sequences representing "unknown methanotrophic bacteria". This limits data interpretation due restricted information about these uncultured methanotrophs. A few groups uncultivated assumed play important roles oxidation specific habitats, while biology behind other sequence clusters remains still largely unknown. The discovery evolutionary related monooxygenases non-methanotrophic pmoA paralogs requires organisms be interpreted with care. review article describes present cultivated based gene diversity. It summarizes current knowledge major evaluates habitat specificity at different levels taxonomic resolution. Habitat exists diverse lineages levels. Methanotrophic genera such Methylocystis Methylocaldum identified generalists, but they harbor species level. finding implies future studies should consider diverging preferences when analyzing communities.

Язык: Английский

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Walking Metals for Remote Functionalization

ACS Central Science, Год журнала: 2018, Номер 4(2), С. 153 - 165

Опубликована: Фев. 8, 2018

The distant and selective activation of unreactive C–H C–C bonds remains one the biggest challenges in organic chemistry. In recent years, development remote functionalization has received growing interest as it allows for rather challenging from initiation point by means a "metal-walk". A "metal-walk" or "chain-walk" is defined an iterative series consecutive 1,2- 1,3-hydride shifts metal complex along single hydrocarbon chain. With this approach, simple building blocks mixtures thereof can be transformed into scaffolds convergent unified strategy. variety catalytic systems have been developed refined over past decade ranging late-transition-metal complexes to more sustainable iron- cobalt-based systems. As possibilities field are slowly unfolding, area research will contribute considerably provide solutions yet unmet synthetic challenges.

Язык: Английский

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Intergenomic Comparisons Highlight Modularity of the Denitrification Pathway and Underpin the Importance of Community Structure for N2O Emissions

PLoS ONE, Год журнала: 2014, Номер 9(12), С. e114118 - e114118

Опубликована: Дек. 1, 2014

Nitrous oxide (N2O) is a potent greenhouse gas and the predominant ozone depleting substance. The only enzyme known to reduce N2O nitrous reductase, encoded by nosZ gene, which present among bacteria archaea capable of either complete denitrification or reduction di-nitrogen gas. To determine whether occurrence nosZ, being proxy for trait reduction, differed taxonomic groups, preferred habitats organisms having NirK NirS nitrite reductases nirK nirS genes, respectively, 652 microbial genomes across 18 phyla were compared. Furthermore, association different co-occurrence patterns with enzymes reducing nitric nor genes was examined. We observed that not randomly distributed taxa, as specific found be more dominant absent than expected within groups. gene had significantly higher frequency presence absence largely explained this pattern, almost always co-occurred nor. This suggests type denitrifiers are likely thus contribute less emissions under favorable environmental conditions. Comparative phylogenetic analysis indicated greater degree shared evolutionary history between nirS. However 30% did possess nir several these also lacking nor, suggesting potentially important role in reduction. Co-occurrence non-randomly amongst habitat categories, showing significant differences frequencies denitrifiers. These results demonstrate pathway highly modular, underpinning importance community structure emissions.

Язык: Английский

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A benzene-degrading nitrate-reducing microbial consortium displays aerobic and anaerobic benzene degradation pathways

Scientific Reports, Год журнала: 2018, Номер 8(1)

Опубликована: Март 8, 2018

In this study, we report transcription of genes involved in aerobic and anaerobic benzene degradation pathways a benzene-degrading denitrifying continuous culture. Transcripts associated with the family Peptococcaceae dominated all samples (21-36% relative abundance) indicating their key role community. We found highly transcribed gene cluster encoding presumed carboxylase (AbcA AbcD) benzoate-coenzyme A ligase (BzlA). Predicted products showed >96% amino acid identity similar order to corresponding described previously, providing further evidence for activation via carboxylation. For subsequent benzoyl-CoA dearomatization, bam-like analogous ones other strict anaerobes were transcribed, whereas transcripts downstream mostly facultative anaerobes. The concurrent enzymes oxygenase-mediated suggested oxygen presence culture, possibly formed recently identified nitric oxide dismutase (Nod). Although unable detect Nod-encoding genes, addition nitrite formate culture indication production. Such an production would enable microbes thrive oxygen-depleted nitrate-containing subsurface environments contaminated hydrocarbons.

Язык: Английский

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Anaerobic Catabolism of Aromatic Compounds: a Genetic and Genomic View

Microbiology and Molecular Biology Reviews, Год журнала: 2009, Номер 73(1), С. 71 - 133

Опубликована: Март 1, 2009

SUMMARY Aromatic compounds belong to one of the most widely distributed classes organic in nature, and a significant number xenobiotics this family compounds. Since many habitats containing large amounts aromatic are often anoxic, anaerobic catabolism by microorganisms becomes crucial biogeochemical cycles sustainable development biosphere. The mineralization facultative or obligate bacteria can be coupled respiration with variety electron acceptors as well fermentation anoxygenic photosynthesis. redox potential electron-accepting system dictates degradative strategy, there is wide biochemical diversity among degraders. However, genetic determinants all these processes mechanisms involved their regulation much less studied. This review focuses on recent findings that standard molecular biology approaches together new high-throughput technologies (e.g., genome sequencing, transcriptomics, proteomics, metagenomics) have provided regarding genetics, regulation, ecophysiology, evolution degradation pathways. These studies revealed more diverse widespread than previously thought, complex metabolic stress programs associated use under conditions starting unraveled. Anaerobic biotransformation based unprecedented enzymes pathways novel capabilities, design regulatory circuits catabolic networks great biotechnological synthetic biology, now feasible approach.

Язык: Английский

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