Yunnan Key Laboratory of Plateau Geographical Process and Environmental Changes, Faculty of Geography, Yunnan Normal University, Kunming 650500, PR China.
State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, PR China.
Int J Syst Evol Microbiol. 2024 Nov;74(11). doi: 10.1099/ijsem.0.006585.
Three Gram-stain-negative, aerobic, short rod-shaped and motile strains (FXH3W, SHGZ20W and SMYT11W) were isolated from freshwater environments in China. Comparisons based on the 16S rRNA gene sequences indicated that strains FXH3W and SHGZ20W showed the highest 16S rRNA gene sequence similarity of about 99.6% to '' MIC 1.5, and strain SMYT11W showed the highest 16S rRNA gene sequence similarity of 99.8% to D4P002, respectively. Observing the phylogenetic trees reconstructed based on the 16S rRNA gene sequences, the species of genera and were not monophyletic and often mixed together. The further reconstructed phylogenomic tree and Genome Taxonomy Database also showed that the species of both genera were polyphyletic, implying that the current taxonomic status of the species of both genera was questionable. The calculated OrthoANIu, digital DNA-DNA hybridization and average amino acid sequence identity (AAI) values supported that strains FXH3W and SHGZ20W should belong to the same novel species and strain SMYT11W should also represent an independent novel species. Combining the AAI values and phylogenomic analyses, the species of genera and should be reassigned to 12 genera (, , , , , , , , , , and ). The AAI values 69.5-76.0% were also proposed as the -specific thresholds for genus delineation. Strain SMYT11W should represent a novel species of the genus , for which the name sp. nov. (type strains SMYT11W=GDMCC 1.4275=KCTC 8304) is proposed. Strains FXH3W and SHGZ20W should represent a novel species of a new genus gen. nov., sp. nov. The type strain of the type species is FXH3W (=GDMCC 1.4096=KCTC 8154).
三株革兰氏阴性、需氧、短杆状和运动的菌株（FXH3W、SHGZ20W 和 SMYT11W）从中国淡水环境中分离得到。基于 16S rRNA 基因序列的比较表明，菌株 FXH3W 和 SHGZ20W 与“MIC 1.5”的 16S rRNA 基因序列相似性最高，约为 99.6%，而菌株 SMYT11W 与“D4P002”的 16S rRNA 基因序列相似性最高，为 99.8%。从基于 16S rRNA 基因序列重建的系统发育树来看，属和属的种不是单系的，经常混合在一起。进一步重建的系统基因组树和基因组分类数据库也表明，这两个属的种都是多系的，这意味着这两个属的种的分类地位值得怀疑。计算的 OrthoANIu、数字 DNA-DNA 杂交和平均氨基酸序列同一性（AAI）值支持菌株 FXH3W 和 SHGZ20W 应属于同一新种，而菌株 SMYT11W 也应代表一个独立的新种。结合 AAI 值和系统基因组分析，属和属的种应重新分配到 12 个属（，，，，，，，，，，和）。AAI 值 69.5-76.0%也被提议作为属划分的特定阈值。菌株 SMYT11W 应代表一个新的属种，建议将其命名为 sp. nov.（模式菌株 SMYT11W=GDMCC 1.4275=KCTC 8304）。菌株 FXH3W 和 SHGZ20W 应代表一个新属的新种，属名 gen. nov.，种名 sp. nov.。模式种的模式株是 FXH3W（=GDMCC 1.4096=KCTC 8154）。
