Maruyama Tomoko, Park Ho-Dong, Ozawa Kazuhiko, Tanaka Yoshinori, Sumino Tatsuo, Hamana Koei, Hiraishi Akira, Kato Kenji
Marine Works Japan Ltd, Kamariyahigashi, 2-16-32 4F, Kanazawa-ku, Yokohama 236-0042, Japan.
Int J Syst Evol Microbiol. 2006 Jan;56(Pt 1):85-9. doi: 10.1099/ijs.0.63789-0.
Three strains of bacteria that degrade the cyanobacterial hepatotoxin microcystin, Y2T, MDB2 and MDB3, were isolated from a eutrophic lake, Lake Suwa, and the Tenryu River, Japan, and characterized. These strains were aerobic and chemo-organotrophic and their cells were Gram-negative, non-spore-forming rods, motile by means of single polar flagella. Yellow-pigmented colonies were formed on nutrient agar media. The strains assimilated only citrate among the organic compounds tested as carbon sources. The G+C content of genomic DNA ranged from 63.6 to 63.7 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the new isolates formed a tight cluster within the family Sphingomonadaceae but were clearly separate from established genera of this family, e.g. Sphingomonas, Sphingobium, Novosphingobium and Sphingopyxis; sequence similarities between the new isolates and type strains from established genera ranged from 90.9 to 94.9 %. Chemotaxonomic and phenotypic data supported the conclusion that these strains were members of the family Sphingomonadaceae. The major components of the cellular fatty acids were 18 : 1omega7c (36-41 %) and 16 : 1omega7c (33-36 %). Hydroxy fatty acids were mainly 2-OH 14 : 0 (11-13 %), and 3-OH fatty acids were absent. Glycosphingolipids were detected. Ubiquinone-10 and homospermidine were present as the major quinine and polyamine, respectively. Thus, it is proposed that the three strains represent a new genus and species of the family Sphingomonadaceae with the name Sphingosinicella microcystinivorans gen. nov., sp. nov. The type strain is Y2T (= KCTC 12019T = JCM 13185T).
从日本富营养化的诹访湖和天龙河中分离出三株能降解蓝藻肝毒素微囊藻毒素的细菌，分别为Y2T、MDB2和MDB3，并对其进行了鉴定。这些菌株为需氧型和化学有机营养型，细胞为革兰氏阴性、无芽孢杆菌，通过单极鞭毛运动。在营养琼脂培养基上形成黄色色素菌落。在所测试的作为碳源的有机化合物中，这些菌株仅同化柠檬酸盐。基因组DNA的G+C含量在63.6%至63.7%之间。基于16S rRNA基因序列的系统发育分析表明，新分离株在鞘脂单胞菌科内形成一个紧密的聚类，但明显与该科已确立的属，如鞘脂单胞菌属、鞘氨醇单胞菌属、新鞘氨醇单胞菌属和鞘脂环杆菌属不同；新分离株与已确立属的模式菌株之间的序列相似性在90.9%至94.9%之间。化学分类学和表型数据支持这些菌株是鞘脂单胞菌科成员的结论。细胞脂肪酸的主要成分是18 : 1ω7c（36 - 41%）和16 : 1ω7c（33 - 36%）。羟基脂肪酸主要是2 - OH 14 : 0（11 - 13%），不存在3 - OH脂肪酸。检测到糖鞘脂。泛醌-10和高亚精胺分别作为主要的醌和多胺存在。因此，提议将这三株菌代表鞘脂单胞菌科的一个新属和新种，命名为微囊藻毒素鞘脂单胞菌（Sphingosinicella microcystinivorans），属名新拟，种名新拟。模式菌株为Y2T（= KCTC 12019T = JCM 13185T）。
