Dissimilatory Fe(III) and Mn(IV) Reduction

Advances in microbial physiology/Advances in Microbial Physiology, Год журнала: 2004, Номер unknown, С. 219 - 286

Опубликована: Янв. 1, 2004

Язык: Английский

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Bug juice: harvesting electricity with microorganisms

Nature Reviews Microbiology, Год журнала: 2006, Номер 4(7), С. 497 - 508

Опубликована: Июнь 16, 2006

Язык: Английский

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Proposal to reclassify the proteobacterial classes Deltaproteobacteria and Oligoflexia, and the phylum Thermodesulfobacteria into four phyla reflecting major functional capabilities

INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY, Год журнала: 2020, Номер 70(11), С. 5972 - 6016

Опубликована: Ноя. 1, 2020

The class Deltaproteobacteria comprises an ecologically and metabolically diverse group of bacteria best known for dissimilatory sulphate reduction predatory behaviour. Although this lineage is the fourth described phylum Proteobacteria , it rarely affiliates with other proteobacterial classes frequently not recovered as a monophyletic unit in phylogenetic analyses. Indeed, one branch encompassing Bdellovibrio- like predators was recently reclassified into separate class, Oligoflexia . Here we systematically explore phylogeny taxa currently assigned to these using 120 conserved single-copy marker genes well rRNA genes. overwhelming majority markers reject inclusion Instead, great recognized members are better classified four novel phylum-level lineages. We propose names Desulfobacterota phyl. nov. Myxococcota two phyla, based on oldest validly published each lineage, retain placeholder name SAR324 third pending formal description type material. Members represent which Bdellovibrionota priority literature general recognition genus Bdellovibrio. includes previously Thermodesulfobacteria reclassifications imply that ability vertically inherited rather than laterally acquired inferred. Our analysis also indicates independent acquisition behaviour phyla consistent their distinct modes action. This work represents stable reclassification most taxonomically challenging areas bacterial tree provides robust framework future ecological systematic studies.

Язык: Английский

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Graphite electrodes as electron donors for anaerobic respiration

Environmental Microbiology, Год журнала: 2004, Номер 6(6), С. 596 - 604

Опубликована: Март 30, 2004

Summary It has been demonstrated previously that Geobacter species can transfer electrons directly to electrodes. In order determine whether electrodes could serve as electron donors for microbial respiration, enrichment cultures were established from a sediment inoculum with potentiostat‐poised graphite electrode the sole donor and nitrate acceptor. Nitrate was reduced nitrite consumption of electrical current. The stoichiometry accumulation consistent serving reduction. Analysis 16 rRNA gene sequences supplied current specifically enriched in microorganisms most closely related known species. A pure culture metallireducens shown reduce expected consumption. Cells attached appeared be responsible Attached cells sulfurreducens fumarate succinate an donor. These results demonstrate first time may direct anaerobic respiration. This finding implications harvesting electricity sediments bioremediation oxidized contaminants.

Язык: Английский

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Detoxification of vinyl chloride to ethene coupled to growth of an anaerobic bacterium

Nature, Год журнала: 2003, Номер 424(6944), С. 62 - 65

Опубликована: Июль 1, 2003

Язык: Английский

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Microbial biodiversity in groundwater ecosystems

Freshwater Biology, Год журнала: 2008, Номер 54(4), С. 649 - 677

Опубликована: Апрель 28, 2008

Summary 1. Groundwater ecosystems offer vast and complex habitats for diverse microbial communities. Here we review the current status of groundwater biodiversity research with a focus on Bacteria Archaea prospects modern techniques enhancing our understanding patterns their relation to environmental conditions. 2. The enormous volume saturated terrestrial underground forms largest habitat microorganisms earth. Up 40% prokaryotic biomass earth is hidden within this subsurface. Besides representing globally important pool carbon nutrients in organisms, these communities harbour degree diversity only marginally explored date. 3. Although first observations microbiota date back Antonie van Leeuwenhoek 1677, systematic investigation has gained momentum last few decades. These investigations were initiated by an increasing awareness importance aquifer ecosystem services functioning, including provision drinking water degradation contaminants. 4. development sampling suitable microbiological as well application both cultivation‐based molecular methods yielded substantial insights into contaminated aquifers, whereas knowledge pristine still poor at present. 5. Several novel phylogenetic lineages have been described from habitats, but no clearly ‘endemic’ subsurface phyla identified. future will show if rather low generally found oligotrophic aquifers fact or just result abundances insufficient resolution today’s methods. Refined approaches complemented statistically rigorous applications estimates are urgently needed. 6. Factors identified control include spatial heterogeneity, temporal variability disturbances such pollution chemical anthropogenic individual biogeochemical processes may be obtained surveys functional groups, direct links functioning rarely established so far.

Язык: Английский

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Anaerobic Microbial Dehalogenation

Annual Review of Microbiology, Год журнала: 2004, Номер 58(1), С. 43 - 73

Опубликована: Окт. 1, 2004

▪ Abstract The natural production and anthropogenic release of halogenated hydrocarbons into the environment has been likely driving force for evolution an unexpectedly high microbial capacity to dehalogenate different classes xenobiotic haloorganics. This contribution provides update on current knowledge metabolic phylogenetic diversity anaerobic microorganisms that are capable dehalogenating—or completely mineralizing—halogenated by fermentative, oxidative, or reductive pathways. In particular, research past decade focused halorespiring anaerobes, which couple dehalogenation dedicated enzyme systems generation energy electron transport–driven phosphorylation. Significant advances in biochemistry molecular genetics degradation pathways have revealed mechanistic structural similarities between dehalogenating enzymes from phylogenetically distinct anaerobes. availability two almost complete genome sequences isolates recently enabled comparative functional genomics approaches, setting stage further exploitation other microbes as degraders biological remediation processes.

Язык: Английский

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Quantitative PCR Targeting 16S rRNA and Reductive Dehalogenase Genes Simultaneously Monitors Multiple Dehalococcoides Strains

Applied and Environmental Microbiology, Год журнала: 2006, Номер 72(4), С. 2765 - 2774

Опубликована: Апрель 1, 2006

ABSTRACT The 16S rRNA gene provides insufficient information to infer the range of chloroorganic electron acceptors used by different Dehalococcoides organisms. To overcome this limitation and provide enhanced diagnostic tools for growth measurements, site assessment, bioremediation monitoring, a quantitative real-time PCR (qPCR) approach targeting genes three reductive dehalogenase (RDase) with assigned function (i.e., tceA , bvcA vcrA ) was designed evaluated. qPCR standard curves generated RDase use genomic DNA from pure cultures correlated obtained both Bacteria - -targeted genes, suggesting that are useful targets assessment probe/primer pairs were specific strains known carry sequences, method allowed detection as few 1 20 quantification 50 100 or per volume. applied dechlorinating enrichment cultures, microcosms, samples contaminated site. In characterized where enumerated, sum equaled total cell numbers. chloroethane-dechlorinating much less than predicted qPCR, totaling 10 30% Hence, large number spp. contain as-yet-unidentified indicating our current understanding community is incomplete.

Язык: Английский

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Anaerobic biodegradation of (emerging) organic contaminants in the aquatic environment

Water Research, Год журнала: 2017, Номер 116, С. 268 - 295

Опубликована: Фев. 4, 2017

Although strictly anaerobic conditions prevail in several environmental compartments, up to now, biodegradation studies with emerging organic contaminants (EOCs), such as pharmaceuticals and personal care products, have mainly focused on aerobic conditions. One of the reasons probably is assumption that degradation more energetically favorable than under Certain aerobically recalcitrant contaminants, however, are biodegraded little known about organisms enzymatic processes involved their degradation. This review provides a comprehensive survey characteristic biotransformation reactions for variety well-studied, structurally rather simple (SMOCs) bearing one or few different functional groups/structural moieties. Furthermore it summarizes complex groups (CMCs), soil, sediment wastewater treatment. While able promote transformation persistent observed limited, reductive dehalogenations cleavage ether bonds being most prevalent. Thus, becomes clear transferability mechanisms deduced from culture SMOCs predict CMCs, EOCs, matrices hampered due chemical structure groups, (e.g. matrix, redox, pH), microbial community adaptation, competition) low concentrations typical EOCs.

Язык: Английский

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Geobacter lovleyi sp. nov. Strain SZ, a Novel Metal-Reducing and Tetrachloroethene-Dechlorinating Bacterium

Applied and Environmental Microbiology, Год журнала: 2006, Номер 72(4), С. 2775 - 2782

Опубликована: Апрель 1, 2006

ABSTRACT A bacterial isolate, designated strain SZ, was obtained from noncontaminated creek sediment microcosms based on its ability to derive energy acetate oxidation coupled tetrachloroethene (PCE)-to- cis -1,2-dichloroethene ( -DCE) dechlorination (i.e., chlororespiration). Hydrogen and pyruvate served as alternate electron donors for the range of acceptors included (reduced products are given in brackets) PCE trichloroethene [ -DCE], nitrate [ammonium], fumarate [succinate], Fe(III) [Fe(II)], malate Mn(IV) [Mn(II)], U(VI) [U(IV)], elemental sulfur [sulfide]. soluble (as ferric citrate) were reduced at rates 56.5 164 nmol min −1 mg protein , respectively, with donor. Alternate acceptors, such nitrate, did not inhibit consumed concomitantly. With PCE, citrate), H 2 threshold concentrations 0.08 ± 0.03 nM, 0.16 0.07 0.5 0.06 3.0 2.1 1.2 3.6 0.25 respectively. Apparently, acceptor-specific consumption exist, suggesting that similar hydrogen model, measurement offers an additional diagnostic tool delineate terminal electron-accepting processes anaerobic subsurface environments. Genetic phenotypic analyses classify SZ type new species, Geobacter lovleyi sp. nov., (formerly Trichlorobacter ) thiogenes closest relative. Furthermore, analysis 16S rRNA gene sequences recovered PCE-dechlorinating consortia chloroethene-contaminated environments suggests belongs a distinct, dechlorinating clade within metal-reducing group. Substrate versatility, low concentrations, simultaneous reduction suggest SZ-type organisms have desirable characteristics bioremediation applications.

Язык: Английский

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