Mao Ya-Ling, Dong Xin-Yue, Tao Cong-Qi, Wu Zhang-Ping, Shi Xiao-Wei, Hou Jing, Cui Heng-Lin
School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, PR China.
School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, PR China.
Syst Appl Microbiol. 2025 Jan;48(1):126577. doi: 10.1016/j.syapm.2024.126577. Epub 2024 Dec 15.
Four novel halophilic archaeal strains CGA53, CG83, FCH27, and SEDH24 were isolated from a soda lake and two saline lakes in China, respectively. Strain CGA53 showed the highest 16S rRNA gene similarity (92.6%) to Salinilacihabitans rarus AD-4, and the other three strains were found to be related to Halalkalicoccus species with similarities of 97.6-98.3%. Metagenomic studies indicated that these four strains are low abundant inhabitants detected in these hypersaline environments, and only one MAG of Chagannuoer Soda Lake (CG) could be assigned to the genus Halalkalicoccus. Their growth occurred at 20-60 °C (optima, 42, 37, 37-42, and 35 °C), 0.9-5.1 M NaCl (optima, 3.9, 2.6, 3.5, and 3 M), and 0-1.0 M MgCl (optima, 0.5, 0.7, and 0.1) and pH 5.5-10.5 (optima, 9.0, 7.5, 7.0, and 7.0), respectively. Phylogenetic and phylogenomic analyses revealed that strains CG83, FCH27, and SEDH24 cluster with the current species of the genus Halalkalicoccus, and strain CGA53 forms an independent branch separated from this genus. The average nucleotide identity (ANI), digital DNA-DNA hybridization (dDDH), and average amino acid identity (AAI) values among strains CGA53, CG83, FCH27, SEDH24, and the type species of the current genera within the class Halobacteria were 67.4-81.6%, 16.5-28.6% and 49.7-74.1%, respectively, clearly lower than the cutoff values for species demarcation. Strain CGA53 may represent a novel species of a new genus according to the cutoff value for genus demarcation of 65% AAI. Diverse differential phenotypic characteristics, such as nutrition, biochemical activities, antibiotic sensitivity, and HS formation, were found among these four strains and Halalkalicoccus species. Genome-based classification supported that strains CGA53, CG83, FCH27, SEDH24, and the current species of Halalkalicoccus represent a novel family of the order Halobacteriales within the class Halobacteria.
分别从中国的一个苏打湖和两个盐湖中分离出了四株新型嗜盐古菌菌株CGA53、CG83、FCH27和SEDH24。菌株CGA53与稀有盐栖嗜碱菌AD-4的16S rRNA基因相似度最高（92.6%），另外三株菌株被发现与嗜盐碱球菌属的物种相关，相似度为97.6%-98.3%。宏基因组研究表明，这四株菌株是在这些高盐环境中检测到的低丰度栖息菌，查干诺尔苏打湖（CG）的仅一个宏基因组组装基因组（MAG）可归为嗜盐碱球菌属。它们的生长温度范围为20-60℃（最适温度分别为42、37、37-42和35℃），NaCl浓度为0.9-5.1M（最适浓度分别为3.9、2.6、3.5和3M），MgCl浓度为0-1.0M（最适浓度分别为0.5、0.7和0.1），pH值为5.5-10.5（最适pH值分别为9.0、7.5、7.0和7.0）。系统发育和系统基因组分析表明，菌株CG83、FCH27和SEDH24与嗜盐碱球菌属的现有物种聚类，而菌株CGA53形成了一个与该属分离的独立分支。菌株CGA53、CG83、FCH27、SEDH24与嗜盐菌纲内当前各属模式种之间的平均核苷酸一致性（ANI）、数字DNA-DNA杂交（dDDH）和平均氨基酸一致性（AAI）值分别为67.4%-81.6%、16.5%-28.6%和49.7%-74.1%，明显低于物种划分的临界值。根据65% AAI的属划分临界值，菌株CGA53可能代表一个新属的新物种。在这四株菌株和嗜盐碱球菌属的物种之间发现了多种不同的表型特征，如营养、生化活性、抗生素敏感性和HS形成。基于基因组的分类支持菌株CGA53、CG83、FCH27、SEDH24以及嗜盐碱球菌属的现有物种代表嗜盐菌纲嗜盐杆菌目一个新的科。
