Ekborg Nathan A, Gonzalez Jose M, Howard Michael B, Taylor Larry E, Hutcheson Steven W, Weiner Ronald M
Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA.
Department of Microbiology and Cell Biology, University of La Laguna, 38206 La Laguna, Tenerife, Spain.
Int J Syst Evol Microbiol. 2005 Jul;55(Pt 4):1545-1549. doi: 10.1099/ijs.0.63627-0.
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.
属于微球菌属并与之相关的γ-变形菌是一类新兴的可降解复杂碳水化合物的海洋细菌。此前，所有这些细菌的代表菌株都被归类于微球菌属或未被分类。最近，一个新属——食木菌属被建立，其仅包含一个物种，即特纳食木菌，用来容纳这些生物的内共生分支。在本研究中，基于16S rRNA基因序列相似性和表型分析，提出了一个新属——食糖菌属，以容纳迄今已鉴定出的最具多能性的海洋碳水化合物降解菌，即食糖降解菌新属新种2-40(T)（=ATCC 43961(T)=DSM 17024(T)）。食糖降解菌菌株2-40(T)能够降解10种经测试的复杂多糖：琼脂、藻酸盐、几丁质、纤维素、岩藻依聚糖、海带多糖、果胶、支链淀粉、淀粉和木聚糖。食糖降解菌2-40(T)与微球菌属模式种水解微球菌IRE-31(T)的16S rRNA基因序列相似度为90.5%，与特纳食木菌T7902(T)的相似度为91.5%，通过16S rRNA基因聚类分析、利用10种不同复杂多糖作为唯一碳源的能力、显著更低的G+C含量以及脂肪酸含量差异，可将其与这两个属的成员进一步区分开来。这三个可降解复杂多糖的海洋细菌属目前涵盖了来自不同海洋生态位的20个菌株。
