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Full-Text Articles in Life Sciences
The Rnf Complex Of Clostridium Ljungdahlii Is A Proton-Translocating Ferredoxin: Nad+ Oxidoreductase Essential For Autotrophic Growth, Pier-Luc Tremblay, Tian Zhang, Shabir Dar, Ching Leang, Derek Lovley
The Rnf Complex Of Clostridium Ljungdahlii Is A Proton-Translocating Ferredoxin: Nad+ Oxidoreductase Essential For Autotrophic Growth, Pier-Luc Tremblay, Tian Zhang, Shabir Dar, Ching Leang, Derek Lovley
Microbiology Department Faculty Publication Series
It has been predicted that the Rnf complex of Clostridium ljungdahlii is a proton-translocating ferredoxin:NAD+ oxidoreductase which contributes to ATP synthesis by an H+-translocating ATPase under both autotrophic and heterotrophic growth conditions. The recent development of methods for genetic manipulation of C. ljungdahlii made it possible to evaluate the possible role of the Rnf complex in energy conservation. Disruption of the C. ljungdahlii rnf operon inhibited autotrophic growth. ATP synthesis, proton gradient, membrane potential, and proton motive force collapsed in the Rnf-deficient mutant with H2 as the electron source and CO2 as the electron acceptor. Heterotrophic growth was hindered in …
Comparative Genomic Analysis Of Geobacter Sulfurreducens Kn400, A Strain With Enhanced Capacity For Extracellular Electron Transfer And Electricity Production, Jessica Butler, Nelson Young, Muktak Aklujkar, Derek Lovley
Comparative Genomic Analysis Of Geobacter Sulfurreducens Kn400, A Strain With Enhanced Capacity For Extracellular Electron Transfer And Electricity Production, Jessica Butler, Nelson Young, Muktak Aklujkar, Derek Lovley
Microbiology Department Faculty Publication Series
Background A new strain of Geobacter sulfurreducens, strain KN400, produces more electrical current in microbial fuel cells and reduces insoluble Fe(III) oxides much faster than the wildtype strain, PCA. The genome of KN400 was compared to wildtype with the goal of discovering how the network for extracellular electron transfer has changed and how these two strains evolved. Results Both genomes were re-annotated, resulting in 14 fewer genes (net) in the PCA genome; 28 fewer (net) in the KN400 genome; and ca. 400 gene start and stop sites moved. 96% of genes in KN400 had clear orthologs with conserved synteny in …
Molecular Analysis Of The In Situ Growth Rate Of Subsurface Geobacter Species, Dawn Holmes, Ludovic Giloteaux, Melissa Barlett, Milind Chavan, Jessica Smith, Kenneth Williams, Michael Wilkins, Philip Long, Derek Lovley
Molecular Analysis Of The In Situ Growth Rate Of Subsurface Geobacter Species, Dawn Holmes, Ludovic Giloteaux, Melissa Barlett, Milind Chavan, Jessica Smith, Kenneth Williams, Michael Wilkins, Philip Long, Derek Lovley
Microbiology Department Faculty Publication Series
Molecular tools that can provide an estimate of the in situ growth rate of Geobacter species could improve understanding of dissimilatory metal reduction in a diversity of environments. Whole genome microarray analyses of the subsurface isolate, Geobacter uraniireducens, grown under a variety of conditions identified a number of genes that are differentially expressed at different specific growth rates. Expression of two genes encoding ribosomal proteins, rpsC and rplL, were further evaluated with quantitative reverse transcription PCR (qRT-PCR) in cells with doubling times ranging from 6.56 h to 89.28 h. Transcript abundance of rpsC correlated best (r2= 0.90) with specific growth …
The Genome Of Pelobacter Carbinolicus Reveals Surprising Metabolic Capabilities And Physiological Features, Muktak Aklujkar, Shelley Haveman, Raymond Didonato, Olga Chertkov, Cliff Han, Miriam Land, Peter Brown, Derek Lovley
The Genome Of Pelobacter Carbinolicus Reveals Surprising Metabolic Capabilities And Physiological Features, Muktak Aklujkar, Shelley Haveman, Raymond Didonato, Olga Chertkov, Cliff Han, Miriam Land, Peter Brown, Derek Lovley
Microbiology Department Faculty Publication Series
Background The bacterium Pelobacter carbinolicus is able to grow by fermentation, syntrophic hydrogen/formate transfer, or electron transfer to sulfur from short-chain alcohols, hydrogen or formate; it does not oxidize acetate and is not known to ferment any sugars or grow autotrophically. The genome of P. carbinolicus was sequenced in order to understand its metabolic capabilities and physiological features in comparison with its relatives, acetate-oxidizing Geobacter species. Results Pathways were predicted for catabolism of known substrates: 2,3-butanediol, acetoin, glycerol, 1,2-ethanediol, ethanolamine, choline and ethanol. Multiple isozymes of 2,3-butanediol dehydrogenase, ATP synthase and [FeFe]-hydrogenase were differentiated and assigned roles according to their …
Microbial Functional Gene Diversity With A Shift Of Subsurface Redox Conditions During In Situ Uranium Reduction, Yuting Liang, Joy Van Nostrand, Lucie N′Guessan, Aaron Peacock, Ye Deng, Philip Long, Tom Resch, Liyou Wu, Zhili He, Guanghe Li, Terry Hazen, Derek Lovley, Jizhong Zhoua
Microbial Functional Gene Diversity With A Shift Of Subsurface Redox Conditions During In Situ Uranium Reduction, Yuting Liang, Joy Van Nostrand, Lucie N′Guessan, Aaron Peacock, Ye Deng, Philip Long, Tom Resch, Liyou Wu, Zhili He, Guanghe Li, Terry Hazen, Derek Lovley, Jizhong Zhoua
Microbiology Department Faculty Publication Series
To better understand the microbial functional diversity changes with subsurface redox conditions during in situ uranium bioremediation, key functional genes were studied with GeoChip, a comprehensive functional gene microarray, in field experiments at a uranium mill tailings remedial action (UMTRA) site (Rifle, CO). The results indicated that functional microbial communities altered with a shift in the dominant metabolic process, as documented by hierarchical cluster and ordination analyses of all detected functional genes. The abundance of dsrAB genes (dissimilatory sulfite reductase genes) and methane generation-related mcr genes (methyl coenzyme M reductase coding genes) increased when redox conditions shifted from Fe-reducing to …
Integrative Analysis Of Geobacter Spp. And Sulfate-Reducing Bacteria During Uranium Bioremediation, M. Barlett, K. Zhuang, R. Mahadevan, Derek Lovley
Integrative Analysis Of Geobacter Spp. And Sulfate-Reducing Bacteria During Uranium Bioremediation, M. Barlett, K. Zhuang, R. Mahadevan, Derek Lovley
Microbiology Department Faculty Publication Series
Enhancing microbial U(VI) reduction with the addition of organic electron donors is a promising strategy for immobilizing uranium in contaminated groundwaters, but has yet to be optimized because of a poor understanding of the factors controlling the growth of various microbial communities during bioremediation. In previous field trials in which acetate was added to the subsurface, there were two distinct phases: an initial phase in which acetate-oxidizing, U(VI)-reducing Geobacter predominated and U(VI) was effectively reduced and a second phase in which acetate-oxidizing sulfate reducing bacteria (SRB) predominated and U(VI) reduction was poor. The interaction of Geobacter and SRB was investigated …
Electrical Conductivity In A Mixed-Species Biofilm, Nikhil Malvankar, Joanne Lau, Kelly Nevin, Ashley Franks, Mark Tuominen, Derek Lovley
Electrical Conductivity In A Mixed-Species Biofilm, Nikhil Malvankar, Joanne Lau, Kelly Nevin, Ashley Franks, Mark Tuominen, Derek Lovley
Microbiology Department Faculty Publication Series
Geobacter sulfurreducens can form electrically conductive biofilms, but the potential for conductivity through mixed species biofilms has not been examined. A current-producing biofilm grown from a wastewater sludge inoculum was highly conductive with low charge transfer resistance even though microorganisms other than Geobacteraceae accounted for nearly half the microbial community.
Role Of The Nife Hydrogenase Hya In Oxidative Stress Defense In Geobacter Sulfurreducens, Pier-Luc Tremblay, Derek Lovley
Role Of The Nife Hydrogenase Hya In Oxidative Stress Defense In Geobacter Sulfurreducens, Pier-Luc Tremblay, Derek Lovley
Microbiology Department Faculty Publication Series
Geobacter sulfurreducens, an Fe(III)-reducing deltaproteobacterium found in anoxic subsurface environments, contains 4 NiFe hydrogenases. Hyb, a periplasmically oriented membrane-bound NiFe hydrogenase, is essential for hydrogen-dependent growth. The functions of the three other hydrogenases are unknown. We show here that the other periplasmically oriented membrane-bound NiFe hydrogenase, Hya, is necessary for growth after exposure to oxidative stress when hydrogen or a highly limiting concentration of acetate is the electron source. The beneficial impact of Hya on growth was dependent on the presence of H(2) in the atmosphere. Moreover, the Hya-deficient strain was more sensitive to the presence of superoxide or hydrogen …
Anaerobic Decomposition Of Switchgrass By Tropical Soil-Derived Feedstock-Adapted Consortia, Kristen Deangelis, Julian L. Fortney, Sharon Borglin, Whendee L. Silver, Blake A. Simmons, Terry C. Hazen
Anaerobic Decomposition Of Switchgrass By Tropical Soil-Derived Feedstock-Adapted Consortia, Kristen Deangelis, Julian L. Fortney, Sharon Borglin, Whendee L. Silver, Blake A. Simmons, Terry C. Hazen
Microbiology Department Faculty Publication Series
Tropical forest soils decompose litter rapidly with frequent episodes of anoxic conditions, making it likely that bacteria using alternate terminal electron acceptors (TEAs) play a large role in decomposition. This makes these soils useful templates for improving biofuel production. To investigate how TEAs affect decomposition, we cultivated feedstock-adapted consortia (FACs) derived from two tropical forest soils collected from the ends of a rainfall gradient: organic matter-rich tropical cloud forest (CF) soils, which experience sustained low redox, and iron-rich tropical rain forest (RF) soils, which experience rapidly fluctuating redox. Communities were anaerobically passed through three transfers of 10 weeks each with …