Ding Hong, Liu Jiahui, Yang Chen, Guo Chaobo, Ding Lijian, Jung Dawoon, Zhang Weiyan
Li Dak Sum Yip Yio Chin Kenneth Li Marine Biopharmaceutical Research Center, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, China.
Front Microbiol. 2022 Jul 22;13:957397. doi: 10.3389/fmicb.2022.957397. eCollection 2022.
A modified cultivation technique was developed and applied to resource mining of uncultured microbes from marine sediments of Meishan Island in the East China Sea. Two novel strains NBU2968 and NBU2984 were isolated by this method but not standard Petri dish, which indicated the modified technique was more effective compared to conventional approaches for isolating uncultured microbes and could be popularized and applied to other aquatic environments. The two novel strains were identified by the polyphasic taxonomic approach. Cells of both strains were observed to be Gram-staining-negative, rod-shaped, nonmotile, aerobic, and yellow-pigmented. Catalase and oxidase activities and hydrolysis of Tweens 40, 60, and 80 of two novel strains were positive. Methyl red reaction, HS production, and hydrolysis of Tween 20 were negative. According to 16S rRNA gene sequence analysis, two novel strains shared the highest similarities (96.4-97.7%) to the species with a validated name in the genus , while shared lower sequence similarities (<95.6%) to all other genera. Phylogenetic analysis revealed that strains NBU2968 and NBU2984 were affiliated with the genus . ANI and dDDH values between the two novel strains and species were 77.4-78.3% and 20.4-20.9%, respectively, which were below the thresholds for species delineation. The 16S rRNA gene sequence similarity, ANI, and dDDH values between the two novel strains were 99.3, 88.9, and 36.3%, respectively, indicating that the two strains represent different species. The genomes of NBU2968 and NBU2984 were 3.28 Mbp with a G+C content of 34.2% and 3.09 Mbp with a G+C content of 34.4%, respectively. The only respiratory quinone was menaquinone-6 (MK-6). The major cellular fatty acids were iso-C, iso-CG, and iso-C 3-OH. The major polar lipids of the two strains were phosphatidylethanolamine, unidentified amino lipids, and unidentified lipids. Based on the above polyphasic characteristics, strains NBU2968 and NBU2984 represent two novel species within the genus , for which the names sp. nov. and sp. nov. are proposed. The type strains are NBU2968 (= MCCC 1K06392= KCTC 82913) and NBU2984 (= MCCC 1K07472= KCTC 92511), respectively.
开发了一种改良培养技术，并将其应用于从中国东海梅山岛海洋沉积物中挖掘未培养微生物资源。通过该方法分离出两株新菌株NBU2968和NBU2984，而不是采用标准培养皿，这表明改良技术在分离未培养微生物方面比传统方法更有效，可推广应用于其他水生环境。采用多相分类法对这两株新菌株进行了鉴定。观察到两株菌株的细胞均为革兰氏阴性、杆状、无运动性、需氧且呈黄色色素。两株新菌株的过氧化氢酶和氧化酶活性以及吐温40、60和80的水解反应均为阳性。甲基红反应、硫化氢产生以及吐温20的水解反应均为阴性。根据16S rRNA基因序列分析，两株新菌株与该属中已确认名称的物种具有最高相似性（96.4 - 97.7%），而与所有其他属的序列相似性较低（<95.6%）。系统发育分析表明，菌株NBU2968和NBU2984隶属于该属。两株新菌株与该属物种之间的ANI和dDDH值分别为77.4 - 78.3%和20.4 - 20.9%，均低于物种划分阈值。两株新菌株之间的16S rRNA基因序列相似性、ANI和dDDH值分别为99.3%、88.9%和36.3%，表明这两株菌株代表不同物种。NBU2968和NBU2984的基因组大小分别为3.28 Mbp，G + C含量为34.2%和3.09 Mbp，G + C含量为34.4%。唯一的呼吸醌为甲基萘醌 - 6（MK - 6）。主要细胞脂肪酸为异C、异CG和异C 3 - OH。两株菌株的主要极性脂为磷脂酰乙醇胺、未鉴定的氨基脂和未鉴定的脂。基于上述多相特征，菌株NBU2968和NBU2984代表该属内的两个新物种，为此提出新物种名称 sp. nov.和 sp. nov.。模式菌株分别为NBU2968（= MCCC 1K06392 = KCTC 82913）和NBU2984（= MCCC 1K07472 = KCTC 92511）。
