Aeromicrobium lacus sp. nov., a novel actinobacterium isolated from a drinking-water reservoir.

An actinobacterial strain, designated CPCC 204604, was isolated from a water sample collected from Sancha Lake, a drinking-water reservoir in Sichuan Province, south-west China. Cells were strictly aerobic, Gram-stain-positive, non-spore-forming and non-motile. Polyphasic taxonomic analysis indicated that galactose and ribose were detected as the diagnostic sugars in the whole-cell hydrolysates, and ll-diaminopimelic acid was the diagnostic diamino acid in cell-wall peptidoglycan. MK-9(H4) was the predominant menaquinone. The phospholipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol and an unidentified phospholipid. The major fatty acids were C16 : 0, C16 : 0 2-OH, C18 : 1ω9c, C18 : 0 and 10-methyl C18:0. The genomic DNA G+C content was 71.2 mol%. In the phylogenetic tree based on 16S rRNA gene sequences, strain CPCC 204604 formed a distinct clade with Aeromicrobium ponti DSM 19178 within the lineage of the genus Aeromicrobium, with the highest 16S rRNA gene sequence similarity of 98.3 % to its closest neighbour. On the basis of the genotypic and phenotypic data, we conclude that strain CPCC 204604 represents a novel species of the genus Aeromicrobium, for which the name Aeromicrobiumlacus sp. nov. is proposed with strain CPCC 204604 (=NBRC 112936=DSM 105424) as the type strain.