Madhaiyan Munusamy, Alex Tan Hian Hwee, Cho Hayoung, Kim Soo-Jin, Weon Hang-Yeon, Kwon Soon-Wo, Whitman William B, Ji Lianghui
Biomaterials and Biocatalysts Group, Temasek Life Sciences Laboratory, National University of Singapore, 1 Research Link, Singapore 117604, Singapore.
Agricultural Microbiology Division, National Institute of Agricultural Science, Rural Development Administration, Wanju-gun, Jeollabuk-do 55365, Republic of Korea.
Int J Syst Evol Microbiol. 2017 Dec;67(12):5150-5158. doi: 10.1099/ijsem.0.002434. Epub 2017 Oct 31.
Two yellow-pigmented isolates, S5-249 and L9-754, originating from surface-sterilized plant tissues of Jatropha curcas L. (Jatropha) cultivars were characterized using a polyphasic taxonomic approach. Strains S5-249 and L9-754 had 16S rRNA genes sharing 94.2 % sequence similarity with each other and 91.6-97.2 % sequence similarity with those of other species in the genus Sphingomonas, suggesting that they represent two potentially novel species. The 16S rRNA gene sequences of strains S5-249 and L9-754 shared the highest similarity to that of Sphingomonas sanguinis NBRC 13937 (96.1 and 97.2 %, respectively). The genomic DNA G+C contents of strains S5-249 and L9-754 were 66.9 and 68.5 mol%, respectively. The respiratory quinone was determined to be Q-10, and the major polyamine was homospermidine. Strains S5-249 and L9-754 contained summed feature 7 (comprising C18 : 1ω7c, C18 : 1ω9t and/or C18 : 1ω12t), C16 : 1, C14 : 0 2-OH and summed feature 4 (C16 : 1ω7t, iso-C15 : 0 2-OH and C16 : 1ω7c) as the major cellular fatty acids. The predominant polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and sphingoglycolipid. The average nucleotide identity (ANI) values between S. sanguinis NBRC 13937 and the two type strains (S5-249 and L9-754) were 72.31 and 77.73 %, respectively. Digital DNA-DNA hybridization (dDDH) studies between the novel strains (S5-249 and L9-754) and other species of the genus Sphingomonas were well below the thresholds used to discriminate between bacterial species. The results of dDDH and physiological tests allowed genotypic and phenotypic differentiation of the strains from each other as well as from the species of the genus Sphingomonas with validly published names. These data strongly support the classification of the strains as representatives of novel species, for which we propose the names Sphingomonas jatrophae sp. nov. (type strain S5-249=DSM 27345=KACC 17593) and Sphingomonas carotinifaciens sp. nov. (type strain L9-754=DSM 27347=KACC 17595).
从麻疯树（Jatropha curcas L.）品种表面消毒的植物组织中分离出两株黄色色素产生菌S5-249和L9-754，采用多相分类法对其进行了表征。菌株S5-249和L9-754的16S rRNA基因彼此间序列相似性为94.2%，与鞘氨醇单胞菌属其他物种的序列相似性为91.6 - 97.2%，这表明它们代表两个潜在的新物种。菌株S5-249和L9-754的16S rRNA基因序列与血鞘氨醇单胞菌（Sphingomonas sanguinis）NBRC 13937的序列相似性最高（分别为96.1%和97.2%）。菌株S5-249和L9-754的基因组DNA G+C含量分别为66.9 mol%和68.5 mol%。确定呼吸醌为Q-10，主要多胺为高亚精胺。菌株S5-249和L9-754含有特征性总和7（包括C18:1ω7c、C18:1ω9t和/或C18:1ω12t）、C16:1、C14:0 2-OH和特征性总和4（C16:1ω7t、异-C15:0 2-OH和C16:1ω7c）作为主要细胞脂肪酸。主要极性脂质为磷脂酰甘油、双磷脂酰甘油、磷脂酰乙醇胺和鞘糖脂。血鞘氨醇单胞菌NBRC 13937与两个模式菌株（S5-249和L9-754）之间的平均核苷酸同一性（ANI）值分别为72.31%和77.73%。新菌株（S5-249和L9-754）与鞘氨醇单胞菌属其他物种之间的数字DNA-DNA杂交（dDDH）研究结果远低于用于区分细菌物种的阈值。dDDH和生理测试结果使得这些菌株彼此之间以及与已有效发表名称的鞘氨醇单胞菌属物种在基因型和表型上得以区分。这些数据有力地支持了将这些菌株分类为新物种的代表，我们为此提议将其命名为麻疯树鞘氨醇单胞菌（Sphingomonas jatrophae）新种（模式菌株S5-249 = DSM 27345 = KACC 17593）和胡萝卜素鞘氨醇单胞菌（Sphingomonas carotinifaciens）新种（模式菌株L9-754 = DSM 27347 = KACC 17595）。
