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A Gram-stain-negative, aerobic, yellow-pigmented, straight rod-shaped bacterium, strain MOLA117T, was isolated from a coastal water sample from the north-western Mediterranean Sea, near Banyuls-sur-Mer, France. On the basis of phylogenetic analysis of the 16S rRNA gene sequence, strain MOLA117T was placed within the family Flavobacteriaceae , but showed less than 93 % 16S rRNA gene sequence similarity to other recognized species within the family. The most closely related genera included Arenibacter , Cellulophaga , Maribacter and Zobellia . The only isoprenoid quinone was menaquinone MK-6 and the predominant fatty acid was iso-C17 : 0 3-OH, representing over 33 % of the total fatty acids. The DNA G+C content was 36.9 mol%. Strain MOLA117T required NaCl for growth, and did not exhibit gliding motility or produce flexirubin. Based on the phenotypic and phylogenetic data, strain MOLA117T should be considered to represent a novel species of a new genus, for which the name Saonia flava gen. nov., sp. nov. is proposed. The type strain of Saonia flava is MOLA117T (=CIP 110873T=DSM 29762T).

A Gram-negative, aerobic, cream-pigmented, non-motile, non-spore-forming straight rod, strain MOLA115T, was isolated from a coastal water sample from the Mediterranean Sea. On the basis of phylogenetic analysis of the 16S rRNA gene sequences, strain MOLA115T was shown to belong to the Gammaproteobacteria , adjacent to members of the genera Marinicella , Arenicella and Kangiella , sharing less than 89 % 16S rRNA gene sequence similarity with strains of all recognized species within the Gammaproteobacteria . The only isoprenoid quinone was ubiquinone-8. Polar lipids in strain MOLA115T included phosphatidylethanolamine, an aminolipid, phosphatidylglycerol and an aminophospholipid. Fatty acid analysis revealed iso-C15 : 0 and iso-C17 : 1ω9c to be the dominant components. The DNA G+C content was 44.5 mol%. Based upon the phenotypic and phylogenetic data, we propose that strain MOLA115T should be considered to represent a novel species in a new genus, for which the name Pleionea mediterranea gen. nov., sp. nov. is proposed. The type strain of Pleionea mediterranea is MOLA115T ( = CIP 110343T = DSM 25350T).

We investigated the impact of water masses originating from freshwater input on bacterial heterotrophic metabolism and community structure at an offshore site in the oligotrophic NW Mediterranean Sea in 2007 and 2008. By combining 16S rRNA gene clone libraries and MICRO-CARD-FISH we determined the dominant operational taxonomic units (OTU) and their contribution to bulk abundance and activity in the presence of buoyant water masses characterized by lower salinity (LSW

The temporal dynamics in bulk bacterial parameters and in the richness of the total and active bacterial community, determined from CE-SSCP fingerprints of 16S rRNA genes and 16S rRNA transcripts, respectively, were followed weekly to bimonthly at an oligotrophic coastal site in the NW Mediterranean Sea. Bacterial abundance, bacterial heterotrophic production, and bacterial and community respiration determined over two seasonal cycles displayed large short-term variability and no pronounced temporal pattern was detectable for these parameters. Concentrations in inorganic nutrients, salinity, or concentrations of chlorophyll a could not significantly explain the temporal variability of the bacterial parameters determined. By contrast, bacterial respiration and the bacterial carbon demand were both negatively correlated with the richness of the active bacterial community, while the bacterial parameters determined herein were not related to the richness of the total bacterial community present. Our results indicate that a reduced number of ribotypes is active when rates of bacteria-mediated carbon processes are high. Our approach, based on fingerprints of 16S rRNA transcripts, could represent an interesting tool to investigate the relationship between the structure and function of marine bacteria, in particular, on short temporal and spatial scales.