Sun Xiao-Meng, Chen Cui, Xue Zhao, He Xiao-Yan, Liu Ning-Hua, Chen Xiu-Lan, Zhang Yu-Zhong, Fan Shou-Jin, Zhang Xi-Ying
State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao 266237, PR China.
Life Science College, Shandong Normal University, Jinan 250014, PR China.
Int J Syst Evol Microbiol. 2019 Jun;71(3). doi: 10.1099/ijsem.0.004730. Epub 2021 Mar 4.
Two Gram-stain-negative, aerobic, rod-shaped bacteria, polar flagellated, designated strains SM2066 and SM1966, were respectively isolated from the surfaces of and macroalgae collected off the coastal areas of Rongcheng, PR China. Strain SM2066 grew at 8-37 °C and with 0.5-7.0 % (w/v) NaCl, while strain SM1966 grew at 5-30 °C and with 0.5-8.5% (w/v) NaCl. Both of them reduced nitrate to nitrite and required Na for growth but neither of them hydrolysed starch and DNA. Phylogenetic analysis based on 16S rRNA gene and single-copy orthologous cluster sequences revealed that both strains SM2066 and SM1966 were affiliated with the genus but formed distinct phylogenetic branches from known species, respectively sharing the highest 16S rRNA gene sequence similarities with type strains of (97.9 %) and (96.7 %). The digital DNA-DNA hybridization and average nucleotide identity values between strains SM2066 and SM1966 and type strains of closely related species were all below 22.9 and 79.9 mol%, respectively. The major fatty acids of the two strains were summed feature 3 (C 6/C 7), summed feature 8 (C 7) and C, with their predominant polar lipids being phosphatidylethanolamine and phosphatidylglycerol, and their sole respiratory quinone being Q-8. The genomic DNA G+C contents of strains SM2066 and SM1966 determined from genomic sequences were 40.3 and 41.6 mol%, respectively. On the basis of the polyphasic evidence presented in this study, strains SM2066 and SM1966 are considered to represent two novel species within the genus , for which the names sp. nov. and sp. nov. are proposed. The type strains are SM2066 (=MCCC 1K04390= KCTC 82372) and SM1966 (=MCCC 1K04387= KCTC 72848), respectively.
从中国山东省荣成市沿海采集的两种大型藻类表面分别分离出两株革兰氏阴性、需氧、杆状、具极生鞭毛的细菌，分别命名为SM2066和SM1966菌株。SM2066菌株在8-37°C和0.5-7.0%（w/v）NaCl条件下生长，而SM1966菌株在5-30°C和0.5-8.5%（w/v）NaCl条件下生长。它们都能将硝酸盐还原为亚硝酸盐，生长需要钠，但都不能水解淀粉和DNA。基于16S rRNA基因和单拷贝直系同源簇序列的系统发育分析表明，SM2066和SM1966菌株均属于该属，但形成了与已知该属物种不同的系统发育分支，分别与该属模式菌株具有最高的16S rRNA基因序列相似性（97.9%）和（96.7%）。SM2066和SM1966菌株与密切相关该属物种模式菌株之间的数字DNA-DNA杂交和平均核苷酸同一性值分别低于22.9和79.9 mol%。这两株菌的主要脂肪酸为总和特征3（C 6/C 7）、总和特征8（C 7）和C，其主要极性脂为磷脂酰乙醇胺和磷脂酰甘油，唯一的呼吸醌为Q-8。根据基因组序列测定，SM2066和SM1966菌株的基因组DNA G+C含量分别为40.3和41.6 mol%。基于本研究提供的多相证据，SM2066和SM1966菌株被认为代表该属内的两个新物种，分别命名为新种和新种。模式菌株分别为SM2066（=MCCC 1K04390=KCTC 82372）和SM1966（=MCCC 1K04387=KCTC 72848）。
