Sangkanu Suthinee, Suriyachadkun Chanwit, Phongpaichit Souwalak
1Department of Microbiology, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, Thailand.
2BIOTEC Culture Collection, Biodiversity and Biotechnological Resource Research Unit, National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Khlong Luang, Pathum Thani, Thailand.
Int J Syst Evol Microbiol. 2019 Jun;69(6):1814-1820. doi: 10.1099/ijsem.0.003399. Epub 2019 Apr 17.
The taxonomic position of an actinomycete designated AMA 120, isolated from mangrove sediment, was clarified by phenotypic, chemotaxonomic and phylogenetic studies. The 16S rRNA gene sequence revealed that strain AMA 120 was most closely related to Gordonia rhizosphera NBRC 16068 (98.9 %), Gordonia polyisoprenivorans NBRC 16320 (98.1 %) and Gordonia bronchialis NBRC 16047 (98.1 %). A fragment of the gyrB gene of strain AMA 120 formed a distinct phyletic line with G. rhizosphera NBRC 16068 (95.4 %). Strain AMA 120 contained meso-diaminopimelic acid, arabinose and galactose as cell-wall components, and MK-9(H2) was the predominant menaquinone. The polar lipid profile for this strain consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannoside and two unidentified phospholipids. Mycolic acid was present. The major fatty acids were C16 : 0, C18 : 1ω9c and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c). The DNA-DNA relatedness values between AMA 120 and close species were below 70 %. There was an obvious distinction in the average nucleotide identity distribution between strain AMA 120 and its closely related strains at around 75-92%. The DNA G+C content of strain AMA 120 was 66.6 mol%. These results, coupled with the phenotypic and chemotaxonomic data, indicated that strain AMA 120 represents a novel species of the genus Gordonia, for which the name Gordoniasediminis sp. nov. is proposed. The type strain is AMA 120 (=TBRC 7109=NBRC 113236).
通过表型、化学分类和系统发育研究，明确了从红树林沉积物中分离出的一株放线菌AMA 120的分类地位。16S rRNA基因序列显示，菌株AMA 120与根际戈登氏菌NBRC 16068（相似度98.9%）、聚异戊二烯戈登氏菌NBRC 16320（相似度98.1%）和支气管戈登氏菌NBRC 16047（相似度98.1%）关系最为密切。菌株AMA 120的gyrB基因片段与根际戈登氏菌NBRC 16068形成了一个独特的系统发育分支（相似度95.4%）。菌株AMA 120含有内消旋二氨基庚二酸、阿拉伯糖和半乳糖作为细胞壁成分，MK-9(H2)是主要的甲基萘醌。该菌株的极性脂质谱由双磷脂酰甘油、磷脂酰甘油、磷脂酰乙醇胺、磷脂酰肌醇、磷脂酰肌醇甘露糖苷和两种未鉴定的磷脂组成。存在分枝菌酸。主要脂肪酸为C16 : 0、C18 : 1ω9c和总和特征3（C16 : 1ω7c和/或C16 : 1ω6c）。AMA 120与近缘种之间的DNA-DNA相关性值低于70%。菌株AMA 120与其近缘菌株在平均核苷酸同一性分布上在75 - 92%左右存在明显差异。菌株AMA 120的DNA G+C含量为66.6 mol%。这些结果，结合表型和化学分类数据，表明菌株AMA 120代表戈登氏菌属的一个新物种，为此提出新名称戈登氏菌矮小种（Gordoniasediminis sp. nov.）。模式菌株为AMA 120（=TBRC 7109=NBRC 113236）。
