Pansomsuay Rawirat, Duangupama Thitikorn, Pittayakhajonwut Pattama, Intaraudom Chakapong, Suriyachadkun Chanwit, He Ya-Wen, Tanasupawat Somboon, Thawai Chitti
Department of Biology, School of Science, King Mongkut's Institute of Technology Ladkrabang, Bangkok, 10520, Thailand.
National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), 113 Thailand Science Park, Phaholyothin Road, Khlong Luang, Pathum Thani, 12120, Thailand.
Arch Microbiol. 2023 Mar 20;205(4):123. doi: 10.1007/s00203-023-03475-2.
An actinomycete, designated strain HSS6-12, was isolated from hot spring sediment collected from Ranong province, Thailand. The strain showed taxonomic characteristics consistent with those of members of the genus Micromonospora. HSS6-12 produced a single spore directly on the substrate mycelium, and no aerial mycelium was detected. The isomer of diamino acid presented in cell wall peptidoglycan was meso-diaminopimelic acid. Arabinose, xylose, glucose, and ribose were detected in whole-cell hydrolysates. MK-10(H), MK-9(H), and MK-10(H) were major menaquinones. Major cellular fatty acids were iso-C, iso-C, and iso-C. Phospholipid profile was composed of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, and phosphatidylinositolmannosides. 16S rRNA gene analysis revealed that HSS6-12 shared the highest 16S rRNA gene sequence similarity with Micromonospora inositola DSM 43819 (99.3%). In contrast, the genome analysis showed that HSS6-12 formed a tight taxonomic position in a phylogenomic tree with Micromonospora endolithica DSM 44398. Moreover, the average nucleotide identity-blast, the digital DNA-DNA hybridization, and the average amino acid identity values between HSS6-12 and M. inositola DSM 43819 and M. endolithica DSM 44398 were 83.1-84.0%, 27.5-28.7%, and 80.4-82.2%, respectively, indicating that HSS6-12 was different species with both closely related Micromonospora-type strains. In addition, HSS6-12 could be discriminated from its closely related type strains by many physiological and biochemical characteristics. Thus, HSS6-12 could be considered a novel species of the genus Micromonospora, and the name Micromonospora thermarum is proposed for the strain. The type strain is HSS6-12 (= BCC 41915 = JCM 17127).
从泰国拉廊府采集的温泉沉积物中分离出一株放线菌，命名为HSS6-12菌株。该菌株的分类学特征与小单孢菌属成员一致。HSS6-12直接在基内菌丝体上产生单个孢子，未检测到气生菌丝体。细胞壁肽聚糖中存在的二氨基酸异构体为内消旋二氨基庚二酸。全细胞水解产物中检测到阿拉伯糖、木糖、葡萄糖和核糖。MK-10(H)、MK-9(H)和MK-10(H)是主要的甲基萘醌。主要的细胞脂肪酸为异-C、异-C和异-C。磷脂谱由双磷脂酰甘油、磷脂酰乙醇胺、磷脂酰甘油、磷脂酰肌醇和磷脂酰肌醇甘露糖苷组成。16S rRNA基因分析表明，HSS6-12与嗜肌小单孢菌DSM 43819的16S rRNA基因序列相似性最高(99.3%)。相比之下，基因组分析表明，HSS6-12在系统发育基因组树中与内生小单孢菌DSM 44398形成了紧密的分类位置。此外，HSS6-12与嗜肌小单孢菌DSM 43819和内生小单孢菌DSM 44398之间的平均核苷酸一致性- blast、数字DNA-DNA杂交和平均氨基酸一致性值分别为8,3.1-84.0%、27.5-28.7%和80.4-82.2%，表明HSS6-12与这两种密切相关的小单孢菌型菌株是不同的物种。此外，HSS6-12可以通过许多生理生化特征与密切相关的模式菌株区分开来。因此，HSS6-12可被认为是小单孢菌属的一个新物种，并为该菌株提议命名为嗜热小单孢菌。模式菌株为HSS6-12(=BCC 41915=JCM 17127)。
