Sinomonas halotolerans sp. nov., an actinobacterium isolated from a soil sample.

A novel actinobacterial strain, designated CFH S0499(T), was isolated from a soil sample collected from Catba island in Halong Bay, Vietnam. The cells were observed to be Gram-stain positive, aerobic, non-motile, curved rods. The strain was found to grow optimally at 28 °C and pH 7.0. Growth was found to occur at 0-7 % NaCl. Chemotaxonomically, the peptidoglycan type was determined to be of the A3α type, with glutamic acid, glycine, alanine and lysine as the major cell wall amino acids. The whole cell sugars were found to contain mannose, galactose, glucose, ribose and rhamnose. The polar lipids were identified as diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, glycolipids and two unidentified phospholipids. The major fatty acids were identified as anteiso-C15:0, iso-C15:0, anteiso-C17:0 and iso-C16:0 and the predominant respiratory quinone as MK-9 (H2), with a minor amount of MK-10 (H4) and MK-8 (H2). The G+C content of the genomic DNA was determined to be 71.8 mol%. The 16S rRNA gene sequence analysis showed that strain CFH S0499(T) should be assigned to the genus Sinomonas and is closely related to members of the species Sinomonas atrocyanea DSM 20127(T) (98.3 %), Sinomonas soli CW 59(T) (98.28 %), Sinomonas flava CW 108(T) (98.26 %), Sinomonas mesophila MPLK 26(T) (97.5 %) and Sinomonas notoginsengisoli SYP-B 575(T) (95.8 %). DNA-DNA hybridizations showed low values (49.1-54.5 %) between strain CFH S0499(T) and its four closest neighbours. Based on phenotypic, chemotaxonomic and phylogenetic analysis, strain CFH S0499(T) is concluded to represent a novel species of the genus Sinomonas, for which the name Sinomonas halotolerans sp. nov. is proposed, with CFH S0499(T) as the type strain (=CCTCC AB2014300(T) = KCTC 39116(T)).