Key Laboratory of Agricultural Microbiomics and Precision Application (MARA), Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Key Laboratory of Agricultural Microbiome (MARA), State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, PR China.
College of Plant Protection, South China Agricultural University, Guangzhou 510642, PR China.
Int J Syst Evol Microbiol. 2023 Nov;73(11). doi: 10.1099/ijsem.0.006152.
Three novel Gram-stain-positive, aerobic and rod-shaped bacterial strains, designated RHCKG28, RHCJP20 and RHCKG23, were isolated from phyllosphere of healthy citrus leaves collected from Renhua County in Guangdong Province, PR China. 16S rRNA gene sequences comparison and phylogenetic analyses showed that they all belonged to the genus , among which strain RHCKG28 showed the highest similarity to NBRC 103064 (99.3 %), while strains RHCJP20 and RHCKG23 showed 99.2 and 99.0 % similarity to JCM 1345, respectively. Phylogenomic analysis showed that the three novel strains were most closely related to JCM 1345 and JCM 1344. The novel strains could be distinguished from their closely related type strains in terms of enzyme activities, substrate assimilation and fatty acid profiles. In addition, the average nucleotide identity and digital DNA-DNA hybridization values between the novel strains and closely related type strains were 84.4‒89.5 % and 24.5‒34.1 %, respectively, which were below the threshold values for species delimitation. They all took anteiso-C, iso-C and anteiso-C as the major fatty acids, menaquinone 9 (MK-9) as the sole predominant respiratory quinone, and ornithine as the principal cell-wall diamino acid. The major polar lipids consisted of phosphatidylglycerol, diphosphatidylglycerol and several unidentified glycolipids. The phenotypic, genotypic and chemotaxonomic data supported that they represent three distinct novel species of the genus , for which the names sp. nov., sp. nov. and sp. nov. are proposed, with RHCKG28 (=GDMCC 1.2667=JCM 34828), RHCJP20 (=GDMCC 1.2668=JCM 34829) and RHCKG23 (=GDMCC 1.2669=JCM 34830) as the type strains, respectively.
从中国广东省仁化县健康柑橘叶片的叶际中分离到三株革兰氏阳性、需氧和杆状的新细菌菌株，命名为 RHCKG28、RHCJP20 和 RHCKG23。16S rRNA 基因序列比较和系统发育分析表明，它们均属于 属，其中菌株 RHCKG28 与 NBRC 103064（99.3%）的相似性最高，而菌株 RHCJP20 和 RHCKG23 与 JCM 1345 的相似性分别为 99.2%和 99.0%。系统基因组分析表明，这三株新菌株与 JCM 1345 和 JCM 1344 最为密切相关。根据酶活性、底物同化和脂肪酸图谱，这些新菌株与它们密切相关的模式菌株可以区分开来。此外，新菌株与密切相关的模式菌株的平均核苷酸同一性和数字 DNA-DNA 杂交值分别为 84.4%至 89.5%和 24.5%至 34.1%，均低于种的界定阈值。它们都以 anteiso-C、iso-C 和 anteiso-C 为主要脂肪酸，menaquinone 9（MK-9）为唯一主要呼吸醌，鸟氨酸为主要细胞壁二氨基庚二酸。主要极性脂由磷脂酰甘油、双磷脂酰甘油和几种未鉴定的糖脂组成。表型、基因型和化学分类数据支持它们代表了 属的三个新的独特种，分别命名为 sp. nov.、 sp. nov. 和 sp. nov.，RHCKG28（=GDMCC 1.2667=JCM 34828）、RHCJP20（=GDMCC 1.2668=JCM 34829）和 RHCKG23（=GDMCC 1.2669=JCM 34830）为模式菌株。
