Pseudomonas sihuiensis sp. nov., isolated from a forest soil in South China.

A Gram-stain negative, motile, rod-shaped bacterium, designated strain WM-2(T), was isolated from a forest soil in Sihui City, South China, and characterized by means of a polyphasic approach. Growth occurred with 0-5 % (w/v) NaCl (optimum 0-1 %) and at pH 5.0-10.5 (optimum pH 8.5) and 4-40 °C (optimum 30 °C) in Luria-Bertani medium. Comparative 16S rRNA gene sequence analyses showed that strain WM-2(T) is a member of the genus Pseudomonas and most closely related to P. guguanensis, P. oleovorans subsp. lubricantis, P. toyotomiensis, P. alcaliphila and P. mendocina with 97.1-96.6 % sequence similarities. In terms of gyrB and rpoB gene sequences, strain WM-2(T) showed the highest similarity with the type strains of the species P. toyotomiensis and P. alcaliphila. The DNA-DNA relatedness values of strain WM-2(T) with P. guguanensis and P. oleovorans subsp. lubricantis was 48.7 and 37.2 %, respectively. Chemotaxonomic characteristics (the main ubiquinone Q-9, major fatty acids C18:1 ω7c/C18:1 ω6c, C16:0 and C16:1 ω7c/C16:1 ω6c and DNA G+C content 65.2 ± 0.7 mol%) were similar to those of members of the genus Pseudomonas. Polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, an unknown aminophospholipid, an unknown phospholipid and five unknown lipids. According to the results of polyphasic analyses, strain WM-2(T) represents a novel species in the genus Pseudomonas, for which the name Pseudomonas sihuiensis sp. nov. is proposed. The type strain is WM-2(T) (=KCTC 32246(T)=CGMCC 1.12407(T)).