Blastomonas aquatica sp nov., a bacteriochlorophyll-containing bacterium isolated from lake water

Yellow or orange-to-brown pigmented, ovoid or rod-shaped, Gram-negative staining, aerobic strains PE 4-5(T) and N5-10 m-1 were isolated from brackish water in Lake Peng Co and fresh to brackish water in Lake Namtso on the Tibetan Plateau, China. Bacteriochlorophyll a was produced by the isolates. The predominant cellular fatty acids were C-16:1, C-17:1 and C-18:1 unsaturated fatty acids, C-17:1 omega 6c (55.3%), C-17:1 omega 8c (13.0%) and C-18:1 omega 7c (10.4%) for PE 4-5(T) and C-(18:1)omega 7c (54.7%) and C-16:1 omega 7C (18.0%) for N5-10 m-1. The polar lipid profiles of strains PE 4-5(T) and N5-10 m-1 were composed of diphosphatidylglycerol, phosphatidylcholine (not detected in N5-10 m-1), phosphatidyldimethylethanolamine, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, phosphatidylglycerol, sphingoglycolipid and an unknown phospholipid. The predominant respiratory quinone was ubiquinone Q10 and the DNA G + C content was 66.0 mol% for both strains. The16S rRNA gene sequence of strain PE 4-5(T) shared 99.0% similarity with that of N5-10 m-1, and 97.56% similarity with those of Blastomonas natatoria LMG 17322(T) and Blastomonas ursincola DSM 9006(T), respectively. The DNA DNA hybridization relatedness between strains PE 4-5(T) and N5-10 m-1 was 79.0 +/- 1.0%, but below 70% with the type strains in the genus Blastomonas. Based on the variability of phylogenetic and phenotypic characteristics, the isolates should be classified as representatives of a novel species of the genus Blastomonas; the name Blastomonas aquatica sp. nov. is proposed. The type strain is PE 4-5(T) (=JCM 30179(T)=CGMCC 1.12851(T)).