Leifsonia stereocauli sp. nov., Isolated from Stereocaulon tomentosum Fr. Lichen

Abstract

A Gram-stain-positive, aerobic, yellow-pigmented, catalase-positive, oxidase-positive, non-motile with no flagella and irregularly rod-shaped, denominated strain YIM 134122^T, was isolated from a Stereocaulon tomentosum Fr. lichen gathered on Baima Snow Mountain in Diqing Tibetan Autonomous Prefecture, Yunnan Province, China. The novel strain grew at pH 6.0-8.0 (optimum, pH 7.0-7.2), 4-35 ℃ (optimum,25-35 ℃), and with the existence of 0-10% (w/v) NaCl (optimum, 0-2%). Phylogenetic analysis on the basis of 16S rRNA gene sequences indicated that strain YIM 134122^T belonged to the genus Leifsonia and presented high levels of 16S rRNA gene sequence similarity with Leifsonia kafniensis JCM 17021^T (97.92%) and Leifsonia psychrotolerans CGMCC 1.12166^T (97.79%). Based on the draft genome sequence, the G + C content of strain YIM 134122^T was found to be 68.41%, and the average nucleotide identity and digital DNA-DNA hybridizations values between strain YIM 134122^T and Leifsonia kafniensis JCM 17021^T and Leifsonia psychrotolerans CGMCC 1.12166^T were 73.78% and 73.75%, and 19.6% and 19.9%, respectively, which were extremely lower than the generally proposed threshold value for species delineation. The predominant polar lipids in strain YIM 134122^T consisted of phosphatidylglycerol, diphosphatidylglycerol, three unknown glycolipids, two unknown phospholipids, and one unknown lipid, whereas MK-10, MK-11 and MK-12 were the main menaquinones. The major fatty acids (> 4%) of the strain contained iso-C_15:0, anteiso-C_15:0, iso-C_16:0 and anteiso-C_17:0. On the basis of phylogenetic, chemotaxonomic, phenotypic and genotypic evidences, it is concluded that strain YIM 134122^T represents a novel species of the genus Leifsonia, for with the name Leifsonia stereocauli sp. nov. is proposed. The type strain is YIM 134122^T (= CGMCC 1.62033^T = MCCC 1K08590^T = KCTC 59219^T).