<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Vriezen, Jan A C</style></author><author><style face="normal" font="default" size="100%">de Bruijn, Frans J</style></author><author><style face="normal" font="default" size="100%">Nüsslein, Klaus</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Identification and characterization of a NaCl-responsive genetic locus involved in survival during desiccation in Sinorhizobium meliloti.</style></title><secondary-title><style face="normal" font="default" size="100%">Appl Environ Microbiol</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Appl. Environ. Microbiol.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Desiccation</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA Transposable Elements</style></keyword><keyword><style  face="normal" font="default" size="100%">Gene Expression Regulation, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">Gene Knockout Techniques</style></keyword><keyword><style  face="normal" font="default" size="100%">Genes, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">Genetic Loci</style></keyword><keyword><style  face="normal" font="default" size="100%">Microbial Viability</style></keyword><keyword><style  face="normal" font="default" size="100%">Mutagenesis, Insertional</style></keyword><keyword><style  face="normal" font="default" size="100%">Osmotic Pressure</style></keyword><keyword><style  face="normal" font="default" size="100%">Sinorhizobium meliloti</style></keyword><keyword><style  face="normal" font="default" size="100%">Sodium Chloride</style></keyword><keyword><style  face="normal" font="default" size="100%">Stress, Physiological</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2013</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2013 Sep</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">79</style></volume><pages><style face="normal" font="default" size="100%">5693-700</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;The Rhizobiaceae are a bacterial family of enormous agricultural importance due to the ability of its members to fix atmospheric nitrogen in an intimate relationship with plants. Their survival as naturally occurring soil bacteria in agricultural soils as well as popular seed inocula is affected directly by drought and salinity. Survival after desiccation in the presence of NaCl is enabled by underlying genetic mechanisms in the model organism Sinorhizobium meliloti 1021. Since salt stress parallels a loss in water activity, the identification of NaCl-responsive loci may identify loci involved in survival during desiccation. This approach enabled identification of the loci asnO and ngg by their reduced ability to grow on increased NaCl concentrations, likely due to their inability to produce the osmoprotectant N-acetylglutaminylglutamine (NAGGN). In addition, the mutant harboring ngg::Tn5luxAB was affected in its ability to survive desiccation and responded to osmotic stress. The desiccation sensitivity may have been due to secondary functions of Ngg (N-acetylglutaminylglutamine synthetase)-like cell wall metabolism as suggested by the presence of a d-alanine-d-alanine ligase (dAla-dAla) domain and by sensitivity of the mutant to &amp;beta;-lactam antibiotics. asnO::Tn5luxAB is expressed during the stationary phase under normal growth conditions. Amino acid sequence similarity to enzymes producing &amp;beta;-lactam inhibitors and increased resistance to &amp;beta;-lactam antibiotics may indicate that asnO is involved in the production of a &amp;beta;-lactam inhibitor.&lt;/p&gt;
</style></abstract><issue><style face="normal" font="default" size="100%">18</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Tremblay, Pier-Luc</style></author><author><style face="normal" font="default" size="100%">Summers, Zarath M</style></author><author><style face="normal" font="default" size="100%">Glaven, Richard H</style></author><author><style face="normal" font="default" size="100%">Nevin, Kelly P</style></author><author><style face="normal" font="default" size="100%">Zengler, Karsten</style></author><author><style face="normal" font="default" size="100%">Barrett, Christian L</style></author><author><style face="normal" font="default" size="100%">Qiu, Yu</style></author><author><style face="normal" font="default" size="100%">Palsson, Bernhard O</style></author><author><style face="normal" font="default" size="100%">Lovley, Derek R</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">A c-type cytochrome and a transcriptional regulator responsible for enhanced extracellular electron transfer in Geobacter sulfurreducens revealed by adaptive evolution.</style></title><secondary-title><style face="normal" font="default" size="100%">Environ Microbiol</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Environ. Microbiol.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Adaptation, Physiological</style></keyword><keyword><style  face="normal" font="default" size="100%">Biodegradation, Environmental</style></keyword><keyword><style  face="normal" font="default" size="100%">Cytochrome c Group</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">Electron Transport</style></keyword><keyword><style  face="normal" font="default" size="100%">Evolution, Molecular</style></keyword><keyword><style  face="normal" font="default" size="100%">Ferric Compounds</style></keyword><keyword><style  face="normal" font="default" size="100%">Gene Expression Profiling</style></keyword><keyword><style  face="normal" font="default" size="100%">Genes, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">Genome, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">Geobacter</style></keyword><keyword><style  face="normal" font="default" size="100%">Mutagenesis, Insertional</style></keyword><keyword><style  face="normal" font="default" size="100%">Mutation</style></keyword><keyword><style  face="normal" font="default" size="100%">Oligonucleotide Array Sequence Analysis</style></keyword><keyword><style  face="normal" font="default" size="100%">Oxidation-Reduction</style></keyword><keyword><style  face="normal" font="default" size="100%">Riboswitch</style></keyword><keyword><style  face="normal" font="default" size="100%">Sequence Analysis, DNA</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2011 Jan</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">13</style></volume><pages><style face="normal" font="default" size="100%">13-23</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The stimulation of subsurface microbial metabolism often associated with engineered bioremediation of groundwater contaminants presents subsurface microorganisms, which are adapted for slow growth and metabolism in the subsurface, with new selective pressures. In order to better understand how Geobacter species might adapt to selective pressure for faster metal reduction in the subsurface, Geobacter sulfurreducens was put under selective pressure for rapid Fe(III) oxide reduction. The genomes of two resultant strains with rates of Fe(III) oxide reduction that were 10-fold higher than those of the parent strain were resequenced. Both strains contain either a single base-pair change or a 1 nucleotide insertion in a GEMM riboswitch upstream of GSU1761, a gene coding for the periplasmic c-type cytochrome designated PgcA. GSU1771, a gene coding for a SARP regulator, was also mutated in both strains. Introduction of either of the GEMM riboswitch mutations upstream of pgcA in the wild-type increased the abundance of pgcA transcripts, consistent with increased expression of pgcA in the adapted strains. One of the mutations doubled the rate of Fe(III) oxide reduction. Interruption of GSU1771 doubled the Fe(III) oxide reduction rate. This was associated with an increased in expression of pilA, the gene encoding the structural protein for the pili thought to function as microbial nanowires. The combination of the GSU1771 interruption with either of the pgcA mutations resulted in a strain that reduced Fe(III) as fast as the comparable adapted strain. These results suggest that the accumulation of a small number of beneficial mutations under selective pressure, similar to that potentially present during bioremediation, can greatly enhance the capacity for Fe(III) oxide reduction in G. sulfurreducens. Furthermore, the results emphasize the importance of the c-type cytochrome PgcA and pili in Fe(III) oxide reduction and demonstrate how adaptive evolution studies can aid in the elucidation of complex mechanisms, such as extracellular electron transfer.</style></abstract><issue><style face="normal" font="default" size="100%">1</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/20636372?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Núñez, Cinthia</style></author><author><style face="normal" font="default" size="100%">Esteve-Núñez, Abraham</style></author><author><style face="normal" font="default" size="100%">Giometti, Carol</style></author><author><style face="normal" font="default" size="100%">Tollaksen, Sandra</style></author><author><style face="normal" font="default" size="100%">Khare, Tripti</style></author><author><style face="normal" font="default" size="100%">Lin, Winston</style></author><author><style face="normal" font="default" size="100%">Lovley, Derek R</style></author><author><style face="normal" font="default" size="100%">Methé, Barbara A</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">DNA microarray and proteomic analyses of the RpoS regulon in Geobacter sulfurreducens.</style></title><secondary-title><style face="normal" font="default" size="100%">J Bacteriol</style></secondary-title><alt-title><style face="normal" font="default" size="100%">J. Bacteriol.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Adaptation, Physiological</style></keyword><keyword><style  face="normal" font="default" size="100%">Amino Acids</style></keyword><keyword><style  face="normal" font="default" size="100%">Bacterial Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Biological Transport</style></keyword><keyword><style  face="normal" font="default" size="100%">Citric Acid Cycle</style></keyword><keyword><style  face="normal" font="default" size="100%">Cytochromes</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrophoresis, Gel, Two-Dimensional</style></keyword><keyword><style  face="normal" font="default" size="100%">Gene Deletion</style></keyword><keyword><style  face="normal" font="default" size="100%">Gene Expression Regulation, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">Geobacter</style></keyword><keyword><style  face="normal" font="default" size="100%">Mass Spectrometry</style></keyword><keyword><style  face="normal" font="default" size="100%">Mutagenesis, Insertional</style></keyword><keyword><style  face="normal" font="default" size="100%">Oligonucleotide Array Sequence Analysis</style></keyword><keyword><style  face="normal" font="default" size="100%">Oxidative Stress</style></keyword><keyword><style  face="normal" font="default" size="100%">Protein Biosynthesis</style></keyword><keyword><style  face="normal" font="default" size="100%">Proteome</style></keyword><keyword><style  face="normal" font="default" size="100%">Regulon</style></keyword><keyword><style  face="normal" font="default" size="100%">Sigma Factor</style></keyword><keyword><style  face="normal" font="default" size="100%">Signal Transduction</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2006</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2006 Apr</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">188</style></volume><pages><style face="normal" font="default" size="100%">2792-800</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">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 activated genes involved in oxidative stress resistance and adaptation to nutrient limitation. Transcription of the cytochrome c oxidase operon, necessary for G. sulfurreducens growth using oxygen as an electron acceptor, and expression of at least 13 c-type cytochromes, including one previously shown to participate in Fe(III) reduction (MacA), were RpoS dependent. Analysis of a subset of the rpoS mutant proteome indicated that 15 major protein species showed reproducible differences in abundance relative to those of the wild-type strain. Protein identification using mass spectrometry indicated that the expression of seven of these proteins correlated with the microarray data. Collectively, these results indicate that RpoS exerts global effects on G. sulfurreducens physiology and that RpoS is vital to G. sulfurreducens survival under conditions typically encountered in its native subsurface environments.</style></abstract><issue><style face="normal" font="default" size="100%">8</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/16585740?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Coppi, M V</style></author><author><style face="normal" font="default" size="100%">Leang, C</style></author><author><style face="normal" font="default" size="100%">Sandler, S J</style></author><author><style face="normal" font="default" size="100%">Lovley, D R</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Development of a genetic system for Geobacter sulfurreducens.</style></title><secondary-title><style face="normal" font="default" size="100%">Appl Environ Microbiol</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Appl. Environ. Microbiol.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Anti-Bacterial Agents</style></keyword><keyword><style  face="normal" font="default" size="100%">Bacterial Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Blotting, Southern</style></keyword><keyword><style  face="normal" font="default" size="100%">Culture Media</style></keyword><keyword><style  face="normal" font="default" size="100%">Deltaproteobacteria</style></keyword><keyword><style  face="normal" font="default" size="100%">Electroporation</style></keyword><keyword><style  face="normal" font="default" size="100%">Fimbriae Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Genetic Complementation Test</style></keyword><keyword><style  face="normal" font="default" size="100%">Genetic Vectors</style></keyword><keyword><style  face="normal" font="default" size="100%">Microbial Sensitivity Tests</style></keyword><keyword><style  face="normal" font="default" size="100%">Mutagenesis, Insertional</style></keyword><keyword><style  face="normal" font="default" size="100%">Nitrogen Fixation</style></keyword><keyword><style  face="normal" font="default" size="100%">Plasmids</style></keyword><keyword><style  face="normal" font="default" size="100%">Transformation, Bacterial</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2001</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2001 Jul</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">67</style></volume><pages><style face="normal" font="default" size="100%">3180-7</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Members of the genus Geobacter are the dominant metal-reducing microorganisms in a variety of anaerobic subsurface environments and have been shown to be involved in the bioremediation of both organic and metal contaminants. To facilitate the study of the physiology of these organisms, a genetic system was developed for Geobacter sulfurreducens. The antibiotic sensitivity of this organism was characterized, and optimal conditions for plating it at high efficiency were established. A protocol for the introduction of foreign DNA into G. sulfurreducens by electroporation was also developed. Two classes of broad-host-range vectors, IncQ and pBBR1, were found to be capable of replication in G. sulfurreducens. In particular, the IncQ plasmid pCD342 was found to be a suitable expression vector for this organism. When the information and novel methods described above were utilized, the nifD gene of G. sulfurreducens was disrupted by the single-step gene replacement method. Insertional mutagenesis of this key gene in the nitrogen fixation pathway impaired the ability of G. sulfurreducens to grow in medium lacking a source of fixed nitrogen. Expression of the nifD gene in trans complemented this phenotype. This paper constitutes the first report of genetic manipulation of a member of the Geobacter genus.</style></abstract><issue><style face="normal" font="default" size="100%">7</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/11425739?dopt=Abstract</style></custom1></record></records></xml>