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Open Access. Powered by Scholars. Published by Universities.®

2006

Selected Works

Derek Lovley

Articles 1 - 5 of 5

Full-Text Articles in Life Sciences

Possible Nonconductive Role Of Geobacter Sulfurreducens Pilus Nanowires In Biofilm Formation, Gemma Reguera, Rachael B. Pollina, Julie S. Nicoll, Derek Lovley Dec 2006

Possible Nonconductive Role Of Geobacter Sulfurreducens Pilus Nanowires In Biofilm Formation, Gemma Reguera, Rachael B. Pollina, Julie S. Nicoll, Derek Lovley

Derek Lovley

Geobacter sulfurreducens required expression of electrically conductive pili to form biofilms on Fe(III) oxide surfaces, but pili were also essential for biofilm development on plain glass when fumarate was the sole electron acceptor. Furthermore, pili were needed for cell aggregation in agglutination studies. These results suggest that the pili of G. sulfurreducens also have a structural role in biofilm formation.


Role Of Red Gsu In Stress Response And Fe(Iii) Reduction In Geobacter Sulfurreducens, Laurie N. Didonato, Sara A. Sullivan, Barbara A. Methѐ, Kelly P. Nevin, Reg England, Derek Lovley Oct 2006

Role Of Red Gsu In Stress Response And Fe(Iii) Reduction In Geobacter Sulfurreducens, Laurie N. Didonato, Sara A. Sullivan, Barbara A. Methѐ, Kelly P. Nevin, Reg England, Derek Lovley

Derek Lovley

Geobacter species are key members of the microbial community in many subsurface environments in which dissimilatory metal reduction is an important process. The genome of Geobacter sulfurreducens contains a gene designated relGsu, which encodes a RelA homolog predicted to catalyze both the synthesis and the degradation of guanosine 3′,5′-bispyrophosphate (ppGpp), a regulatory molecule that signals slow growth in response to nutrient limitation in bacteria. To evaluate the physiological role of RelGsu in G. sulfurreducens, a relGsu mutant was constructed and characterized, and ppGpp levels were monitored under various conditions in both the wild-type and relGsu mutant strains. In ...


Biofilm And Nanowire Production Leads To Increased Current In Geobacter Sulfurreducens Fuel Cells, Gemma Reguera, Kelly P. Nevin, Julie S. Nicoll, Sean F. Covalla, Trevor L. Woodard, Derek Lovley Aug 2006

Biofilm And Nanowire Production Leads To Increased Current In Geobacter Sulfurreducens Fuel Cells, Gemma Reguera, Kelly P. Nevin, Julie S. Nicoll, Sean F. Covalla, Trevor L. Woodard, Derek Lovley

Derek Lovley

Geobacter sulfurreducens developed highly structured, multilayer biofilms on the anode surface of a microbial fuel cell converting acetate to electricity. Cells at a distance from the anode remained viable, and there was no decrease in the efficiency of current production as the thickness of the biofilm increased. Genetic studies demonstrated that efficient electron transfer through the biofilm required the presence of electrically conductive pili. These pili may represent an electronic network permeating the biofilm that can promote long-range electrical transfer in an energy-efficient manner, increasing electricity production more than 10-fold.


Two Putative C-Type Multiheme Cytochromes Required For The Expression Of Omcb, And Outer Membrane Protein Essential For Optimal Fe(Iii) Reduction In Geobacter Sulfurreducens, Byoung-Chan Kim, Xinlei Qian, Ching Leang, Maddalena V. Coppi, Derek Lovley Jan 2006

Two Putative C-Type Multiheme Cytochromes Required For The Expression Of Omcb, And Outer Membrane Protein Essential For Optimal Fe(Iii) Reduction In Geobacter Sulfurreducens, Byoung-Chan Kim, Xinlei Qian, Ching Leang, Maddalena V. Coppi, Derek Lovley

Derek Lovley

Deletion of two homologous Geobacter sulfurreducens c-type cytochrome genes, omcG and omcH, decreased the rate of Fe(III) reduction and decreased the level of an outer membrane cytochrome critical for Fe(III) reduction, OmcB, without affecting its transcription. Expression of either gene restored Fe(III) reduction and OmcB expression, suggesting functional similarity.


Dna Microarray And Proteomic Analyses Of The Rpos Regulon In Geobacter Sulfurreducens, Carol Giometti, Cinthia Núñez, Sandra Tollaksen, Abraham Esteve-Núñez, Tripti Khare, Winston Lin, Derek Lovley, Barbara Methѐ Jan 2006

Dna Microarray And Proteomic Analyses Of The Rpos Regulon In Geobacter Sulfurreducens, Carol Giometti, Cinthia Núñez, Sandra Tollaksen, Abraham Esteve-Núñez, Tripti Khare, Winston Lin, Derek Lovley, Barbara Methѐ

Derek Lovley

The regulon of the sigma factor RpoS was defined in Geobacter sulfurreducens by using a combination of DNA microarray expression profiles and proteomics. An rpoS mutant was examined under steady-state conditions with acetate as an electron donor and fumarate as an electron acceptor and with additional transcriptional profiling using Fe(III) as an electron acceptor. Expression analysis revealed that RpoS acts as both a positive and negative regulator. Many of the RpoS-dependent genes determined play roles in energy metabolism, including the tricarboxylic acid cycle, signal transduction, transport, protein synthesis and degradation, and amino acid metabolism and transport. As expected, RpoS ...