Halovulum marinum sp. nov., isolated from deep-sea water of the Indian Ocean, and emended description of the genus Halovulum

A novel Gram-stain-negative, aerobic, motile by peritrichous flagella, oval to rod-shaped bacterium, designated strain 2CG4(T), was isolated from a deep-sea water sample collected from the Northwest Indian Ocean. The results of phylogenetic analysis of both 16S rRNA gene and RpoC protein sequences indicated that this strain was affiliated with the genus Halovulum in the Amaricoccus Glade of the family Rhodobacteraceae of the class Alphaproteobacteria, sharing 95.3% similarity at the 16S rRNA gene sequence level with the type strain of Halovulum dunhuangense YYQ-30(T), the only species in the genus Halovulum. The predominant fatty acids (>10%) of 2CG4(T) were summed feature 8 (C-18:1 omega 7c and/ or C-18:1 omega 6c;61.1%) and cyclo-C-19:0 omega 8c (15.6%). The polar lipids of 2CG4(T) were phosphatidylethanolamine, phosphatidylmethylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylcholine and sulfoquinovosyldiacylglycerol. The only isoprenoid quinone of 2CG4(T )was ubiquinone-10. The DNA G+C content of 2CG4(T) was determined to be 69.4%. The central gene pufLM for the photosynthetic reaction was not detected. No growth occurred for 2CG4(T) in the absence of NaCl. On the basis of these data, it is concluded that the 2CG4(T) represents a novel species of the genus Halovulum, for which the name Halovulum marinum sp. nov. is proposed. The type strain is 2CG4(T) (=CGMCC 1.16468(T) =JCM 32611(T)).