Genome Analysis of Marine Bacterial Strains belonging to the OM60/NOR5 Clade of Gammaproteobacteria

초록

The OM60/NOR5 clade of Gammaproteobacteria is of significant ecological importance since its high abundance in coastal waters. Organisms from this clade comprise up to 11% of the bacterial communities in the ocean surface, which include the aerobic anoxygenic photoheterotrophs (AAnP), represented by Congregibacter litoralis KT71 and HTCC2080. In this study, three isolates from coastal surface waters, IMCC3088 (NOR5-4 subclade), IMCC14385 (Halioglobus sp.) and IMCC14734 (unclassified subclade), in the OM60/NOR5 clade were selected for whole genome sequencing. Two complete genomes of IMCC3088 and IMCC14385 comprised of 3,095,392 and 4,306,437 bases, 2915 and 3918 predicated ORFs, 51.7% and 56.7% G+C content, respectively. Draft genome of IMCC14734 containing 20 contigs comprised of 4,835,928 bases, 4418 predicated ORFs, and 54.2% G+C content. Unexpectedly, no puf genes for photosynthesis were harbored by those three strains. Interestingly, IMCC3088 and IMCC14734 possess proteorhodopsin (PR) gene instead of puf genes, indicating their different photo-lifestyles. These genomes not only can help us to elucidate the life strategy and ecotype differentiation of members of the OM60/NOR5 clade, but enrich the genetic materials for more comprehensive investigation on the adaptation of proteorhodopsin-containing strains in the nutrientpoor ocean surface. [This study was supported by a grant from the Marine Biotechnology Program (PJT200620) funded by the MOF, Korea.]