Pitiwittayakul Nittaya, Yukphan Pattaraporn, Charoenyingcharoen Piyanat, Tanasupawat Somboon
Faculty of Agricultural Innovation and Technology, Rajamangala University of Technology Isan, Nakhon Ratchasima Campus, Nakhon Ratchasima 30000, Thailand.
Microbial Diversity and Utilization Research Team, Thailand Bioresource Research Center (TBRC), National Center for Genetic Engineering and Biotechnology (BIOTEC), Pathumthani 12120, Thailand.
Heliyon. 2024 Jun 10;10(12):e32825. doi: 10.1016/j.heliyon.2024.e32825. eCollection 2024 Jun 30.
Two novel endophytic bacterial strains, designated KSS8 and KSS12, were isolated from the stems and roots of sugarcane, respectively, collected in Nakhon Ratchasima, Thailand. They were Gram-stain-negative, aerobic, and rod-shaped. The strain KSS8 was a motile bacterium with a subpolar flagellum, while the strain KSS12 was non-motile. Strains KSS8 and KSS12 were closely related to PAMC 26569 (97.3 and 95.6 %, respectively) and KEBCLARHB70R (97.2 and 95.8 %, respectively) based on the similarity on their 16S rRNA gene sequence. This similarity corresponded to their phylogenomic positions within the evolutionary radiation of the family . The average nucleotide identities and digital DNA-DNA hybridization values between the genome sequences of the two strains and other genera were significantly lower than the defined threshold values of 95-96 % and 70 %, respectively, which are used for the delineation of prokaryotic species. Both strains contained summed feature 8 (C 7 and/or C 6), C, C cyclo 8, C, and C 2OH as the predominant cellular fatty acids, but C 6 (6, 9, 12) were found only in strain KSS12. Based on phenotypic, chemotaxonomic, phylogenetic, and genomic analyses, these strains clearly represented two novel genera within the family , for which the name gen. nov., with the type species sp. nov. (type strain, KSS8 = TBRC 14669 = NBRC 115232 = KCTC 92115 = LMG 32414) and the name gen. nov., with the type species sp. nov. (type strain, KSS12 = TBRC 13066 = NBRC 114898 = KCTC 82433 = LMG 32137) are proposed.
从泰国呵叻府采集的甘蔗茎和根部分别分离出两株新型内生细菌菌株，命名为KSS8和KSS12。它们革兰氏染色阴性，好氧，呈杆状。菌株KSS8是具有亚极鞭毛的运动型细菌，而菌株KSS12不运动。基于16S rRNA基因序列的相似性，菌株KSS8和KSS12分别与PAMC 26569（分别为97.3%和95.6%）以及KEBCLARHB70R（分别为97.2%和95.8%）密切相关。这种相似性与其在该科进化辐射中的系统发育位置相对应。两株菌株与其他属的基因组序列之间的平均核苷酸同一性和数字DNA - DNA杂交值分别显著低于用于界定原核生物物种的95 - 96%和70%的定义阈值。两株菌株均以特征性总和8（C7和/或C6）、C、C环8、C和C2OH作为主要细胞脂肪酸，但C6（6, 9, 12）仅在菌株KSS12中发现。基于表型、化学分类、系统发育和基因组分析，这些菌株明确代表了该科内的两个新属，为此提出新属名gen. nov.，模式种为sp. nov.（模式菌株，KSS8 = TBRC 14669 = NBRC 115232 = KCTC 92115 = LMG 32414）以及新属名gen. nov.，模式种为sp. nov.（模式菌株，KSS12 = TBRC 13066 = NBRC 114898 = KCTC 82433 = LMG 32137）。
