Psychromicrobium lacuslunae sp. nov., isolated from a high altitude lake.

The novel strain IHBB 11108 was a psychrotolerant and alkaliphilic bacterium isolated from the subsurface water of Chandra Tal Lake in the Lahaul-Spiti valley located in the Indian trans-Himalayas. Cells were Gram-stain-positive, aerobic, non-motile, catalase-positive and oxidase-negative. The strain grew at 5-37 °C (optimum 28 °C), pH 5.0-12.0 (optimum pH 7.0) and with up to 8 % NaCl (optimum 1 %). The 16S rRNA gene sequence analysis revealed the highest relatedness of strain IHBB 11108 with Psychromicrobium silvestre DSM 102047 (97.5 %), Arthrobacter russicus DSM 14555 (97.4 %) and Renibacterium salmoninarum ATCC 33209 (97.4 %). The strain contained a quinone system with 57.2 % MK-9(H2), 39.1 % MK-10(H2), 3.0 % MK-8(H2) and 0.7 % MK-7(H2). The polar lipids detected were diphosphatidylglycerol, dimannosylglyceride, phosphatidylinositol, phosphatidylglycerol, monogalactosyldiacylglycerol, one unidentified glycolipid and four unidentified lipids. The cell-wall peptidoglycan structure type was A3α l-Lys-l-Thr-l-Ala with substitution of the α-carboxyl group of d-Glu by alanine amide. Anteiso-C15 : 0, iso-C16 : 0 and anteiso-C17 : 0 were the predominant fatty acids. The genomic DNA G+C content was 59.0 mol%. The DNA-DNA relatedness of strain IHBB 11108 was 46.7±2.2, 43.1±2.5 and 19.1±2.4 % with P. silvestre DSM 102047, A. russicus DSM 14555 and R. salmoninarum ATCC 33209, respectively. On the basis of the results of the phenotypic, chemotaxonomic and phylogenetic analyses, IHBB 11108 is considered to represent a novel species of the genus Psychromicrobium for which the name Psychromicrobium lacuslunae sp. nov. is proposed. The type strain is IHBB 11108 (=MTCC 12460=MCC 2780=JCM 31143=KACC 19070).