Saccharophagus degradans gen. nov., sp nov., a versatile marine degrader of complex polysaccharides

Gammaproteobacteria belonging and related to the genus Microbulbifer are an emerging group of complex carbohydrate-degrading marine bacteria. Previously, all of the representatives were placed within Microbulbifer or were unclassified. Recently, a new genus, Teredinibacter, represented by a single species, Teredinibacter turnerae, was formed to include an endosymbiotic branch of these organisms. In this study, based on 16S rRNA gene sequence similarity and phenotypic analyses, a new genus, Saccharophagus, is proposed to accommodate the most versatile marine carbohydrate degrader yet identified, Saccharophagus degradans gen. nov., sp. nov. 2-40(T) (=ATCC 43961(T)=DSM 17024(T)). S. degradans strain 2-40(T) can degrade 10 tested complex polysaccharides: agar, alginate, chitin, cellulose, fucoidan, laminarin, pectin, pullulan, starch and xylan. S. degradans 2-40(T) shares 90.5% 16S rRNA gene sequence similarity with the type strain of the Microbulbifer type species, Microbulbifer hydrolyticus IRE-31(T), and 91.5% with T. turnerae T7902(T), and can be further distinguished from members of these two genera by 16S rRNA gene cluster analysis, the ability to utilize 10 different complex polysaccharides; as sole carbon sources, a significantly lower G+C content and differences in fatty acid content. The three genera of complex polysaccharide-degrading, marine bacteria now encompass 20 strains from diverse marine niches.