Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, PR China.
School of Marine Sciences, China University of Geosciences, Beijing 100083, PR China.
Int J Syst Evol Microbiol. 2024 Mar;74(3). doi: 10.1099/ijsem.0.006299.
Two Gram-positive, non-motile, short rod-shaped actinomycete strains, designated as A18JL241 and Y20, were isolated from deep-sea sediment samples collected from the Southwest Indian Ocean and Western Pacific Ocean, respectively. Both of the isolates were able to grow within the temperature range of 5-40 °C, NaCl concentration range of 0-7 % (w/v) and at pH 6.0-12.0. The two most abundant cellular fatty acids of both strains were anteiso-C and anteiso-C. The major polar lipid contents of the two strains were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and one unidentified glycolipid. These two strains shared common chemotaxonomic features comprising MK-10 and MK-12 as the respiratory quinones. The genomic DNA G+C contents of the two strains were 68.1 and 70.4 mol%, respectively. The 16S rRNA gene phylogeny showed that the novel strains formed two distinct sublines within the genus . Strain A18JL241 was most closely related to the type strain of KCTC 49593 (98.8 % sequence similarity), whereas strain Y20 formed a tight cluster with the type strain of NBRC 15075 (99.0 %). The orthologous average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values with the type strains of related species were in the range of 74.1-89.1 % and 19.4-36.9 %, respectively, which were below the recognized thresholds of 95-96 % ANI and 70 % dDDH for species definition. Based on the results obtained here, it can be concluded that strains A18JL241 and Y20 represent two novel species of the genus , for which the names sp. nov. (type strain A18JL241=JCM 33956=MCCC 1A16622) and sp. nov. (type strain Y20=JCM 33960=MCCC 1A16747) are proposed.
两株革兰氏阳性、非运动、短杆状放线菌菌株，分别命名为 A18JL241 和 Y20，分别从西南印度洋和西太平洋深海沉积物样本中分离得到。这两株菌都能在 5-40°C、0-7%（w/v）NaCl 和 pH 6.0-12.0 的温度范围内生长。两株菌最丰富的细胞脂肪酸均为 anteiso-C 和 anteiso-C。两株菌的主要极性脂包括磷脂酰甘油、双磷脂酰甘油、磷脂酰乙醇胺和一种未知的糖脂。这两株菌具有共同的化学生态特征，包括 MK-10 和 MK-12 作为呼吸醌。两株菌的基因组 DNA G+C 含量分别为 68.1 和 70.4 mol%。16S rRNA 基因系统发育分析表明，这两个新菌株在 属内形成了两个不同的亚系。A18JL241 菌株与 KCTC 49593 （98.8%序列相似性）的模式菌株最为密切相关，而 Y20 菌株与 NBRC 15075 （99.0%）的模式菌株形成紧密的聚类。与相关 种的模式菌株的直系同源平均核苷酸同一性（ANI）和数字 DNA-DNA 杂交（dDDH）值分别在 74.1-89.1%和 19.4-36.9%之间，均低于种定义的 95-96%ANI 和 70% dDDH 的公认阈值。基于这些结果，可以得出结论，菌株 A18JL241 和 Y20 代表 属的两个新种，分别命名为 sp. nov.（A18JL241 型株=JCM 33956=MCCC 1A16622）和 sp. nov.（Y20 型株=JCM 33960=MCCC 1A16747）。
