03097nas a2200325   4500008004100000245012300041210006900164260001600233520197300249100001902222700001902241700002402260700002102284700001702305700003102322700002002353700003002373700002502403700002402428700001902452700001902471700002102490700002602511700002402537700002902561700001802590700002002608700001902628856012402647       2010                        eng d00aFine-scale evolution: genomic, phenotypic and ecological differentiation in two coexisting Salinibacter ruber strains.0 aFinescale evolution genomic phenotypic and ecological differenti  c2010 Feb 183 a<p>Genomic and metagenomic data indicate a high degree of genomic variation within microbial populations, although the ecological and evolutive meaning of this microdiversity remains unknown. Microevolution analyses, including genomic and experimental approaches, are so far very scarce for non-pathogenic bacteria. In this study, we compare the genomes, metabolomes and selected ecological traits of the strains M8 and M31 of the hyperhalophilic bacterium Salinibacter ruber that contain ribosomal RNA (rRNA) gene and intergenic regions that are identical in sequence and were simultaneously isolated from a Mediterranean solar saltern. Comparative analyses indicate that S. ruber genomes present a mosaic structure with conserved and hypervariable regions (HVRs). The HVRs or genomic islands, are enriched in transposases, genes related to surface properties, strain-specific genes and highly divergent orthologous. However, the many indels outside the HVRs indicate that genome plasticity extends beyond them. Overall, 10% of the genes encoded in the M8 genome are absent from M31 and could stem from recent acquisitions. S. ruber genomes also harbor 34 genes located outside HVRs that are transcribed during standard growth and probably derive from lateral gene transfers with Archaea preceding the M8/M31 divergence. Metabolomic analyses, phage susceptibility and competition experiments indicate that these genomic differences cannot be considered neutral from an ecological perspective. The results point to the avoidance of competition by micro-niche adaptation and response to viral predation as putative major forces that drive microevolution within these Salinibacter strains. In addition, this work highlights the extent of bacterial functional diversity and environmental adaptation, beyond the resolution of the 16S rRNA and internal transcribed spacers regions.The ISME Journal advance online publication, 18 February 2010; doi:10.1038/ismej.2010.6.</p>1 aPeña, Arantxa1 aTeeling, Hanno1 aHuerta-Cepas, Jaime1 aSantos, Fernando1 aYarza, Pablo1 aBrito-Echeverría, Jocelyn1 aLucio, Marianna1 aSchmitt-Kopplin, Philippe1 aMeseguer, Inmaculada1 aSchenowitz, Chantal1 aDossat, Carole1 aBarbe, Valerie1 aDopazo, Joaquín1 aRosselló-Mora, Ramon1 aSchüler, Margarete1 aGlöckner, Frank, Oliver1 aAmann, Rudolf1 aGabaldón, Toni1 aAntón, Josefa  uhttp://clinbioinfosspa.es/content/fine-scale-evolution-genomic-phenotypic-and-ecological-differentiation-two-coexisting