Liu Yue, Zhang Gui, Yang Jing, Cheng Yanpeng, Ye Lin, Lai Xin-He, Yang Caixin, Ma Caiyun, Tao Yuanmeihui, Jin Dong, Lu Shan, Liu Liyun, Xu Jianguo
Department of Epidemiology, Shanxi Medical University School of Public Health, Taiyuan, Shanxi, 030001, PR China.
State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 102206, PR China.
Int J Syst Evol Microbiol. 2023 Apr;73(4). doi: 10.1099/ijsem.0.005742.
Six aerobic or facultative anaerobic, motile, Gram-stain-positive, catalase-positive and oxidase-negative strains (zg-Y453, zg-Y324, zg-Y462, zg-Y411, zg-Y809 and zg-Y786) were isolated from different faecal samples of from the Qinghai-Tibet Plateau. Pale yellow, round, raised and moist colonies appeared 48 h after incubation at 28 °C on brain-heart infusion plates supplemented with 5 % defibrinated sheep blood. According to the 16S rRNA gene sequence alignment, two strain pairs (zg-Y453/zg-Y324 and zg-Y462/zg-Y411) shared the highest similarities to (99.5 and 99.2 %), and the other one (zg-Y809/zg-Y786) to (99.5 %). Results of phylogenetic analysis based on the 16S rRNA gene and genome sequences showed that these six strains represented three separate species within the genus . The average nucleotide identity and digital DNA-DNA hybridization values between the three novel type strains (zg-Y453/zg-Y462/zg-Y809) and other known species in this genus were all below respective thresholds (70.2-81.5/19.6-24.2 %, 70.6-81.8/19.8-25.0 %, and 70.4-88.2/19.9-35.3 %). Although phylogenetically related, there were obvious chemotaxonomic and phenotypic differences: strain pair zg-Y462/zg-Y411 had C as the only major fatty acid; the three novel species had different dominant quinones, MK-8(H) in strains zg-Y462/zg-Y809 (74.8/81.1 %) and MK-8(H)/MK-9(H) (43.1/53.0 %) in zg-Y453; similarly, the ability to reduce nitrate in strains zg-Y453 and zg-Y462 could differentiate them from zg-Y809. All strains had diphosphatidylglycerol, phosphatidylglycerol and phosphatidylinositol, but differed slightly in the types of unidentified glycolipids, phospholipids and lipids. Based on the results of these polyphasic taxonomic analyses, three novel species within the genus are proposed, namely sp. nov. (type strain, zg-Y453=GDMCC 1.2809=JCM 35173), sp. nov. (type strain, zg-Y462=GDMCC 1.2880=JCM 35170) and sp. nov. (type strain, zg-Y809=GDMCC 1.2808=JCM 35168).
从青藏高原不同粪便样本中分离出6株需氧或兼性厌氧、运动、革兰氏染色阳性、过氧化氢酶阳性且氧化酶阴性的菌株（zg-Y453、zg-Y324、zg-Y462、zg-Y411、zg-Y809和zg-Y786）。在补充有5%脱纤维羊血的脑心浸液平板上于28℃培养48小时后，出现淡黄色、圆形、凸起且湿润的菌落。根据16S rRNA基因序列比对，两对菌株（zg-Y453/zg-Y324和zg-Y462/zg-Y411）与[具体菌株名称1]具有最高相似度（分别为99.5%和99.2%），另一对（zg-Y809/zg-Y786）与[具体菌株名称2]具有最高相似度（99.5%）。基于16S rRNA基因和基因组序列的系统发育分析结果表明，这6株菌株代表了该属内三个不同的物种。三株新型菌株（zg-Y453/zg-Y462/zg-Y809）与该属其他已知物种之间的平均核苷酸同一性和数字DNA-DNA杂交值均低于各自阈值（分别为70.2 - 81.5/19.6 - 24.2%、70.6 - 哈81.8/19.8 - 25.0%以及70.4 - 88.2/19.9 - 35.3%）。尽管在系统发育上相关，但存在明显的化学分类学和表型差异：菌株对zg-Y462/zg-Y411以C作为唯一主要脂肪酸；这三个新物种具有不同的优势醌，zg-Y462/zg-Y809菌株中的MK-8(H)（分别为74.8/81.1%）以及zg-Y453中的MK-8(H)/MK-9(H)（43.1/53.0%）；同样，zg-Y453和zg-Y462菌株还原硝酸盐的能力使其与zg-Y809有所不同。所有菌株均含有双磷脂酰甘油、磷脂酰甘油和磷脂酰肌醇，但在未鉴定的糖脂、磷脂和脂质类型上略有差异。基于这些多相分类分析结果，提出该属内三个新物种，即[新物种名称1]sp. nov.（模式菌株，zg-Y453 = GDMCC 1.2809 = JCM 35173）、[新物种名称2]sp. nov.（模式菌株，zg-Y462 = GDMCC 1.2880 = JCM 35170）和[新物种名称3]sp. nov.（模式菌株，zg-Y809 = GDMCC 1.2808 = JCM 35168）。
