Oceanobacillus oncorhynchi subsp. incaldanensis susp. nov., an alkalitolerant halophile isolated from an algal mat collected from a sulfurous spring in Campania (Italy), and emended description of Oceanobacillus oncorhynchi

A halophilic, alkalitolerant bacterium, strain 20AG(T), was isolated from an algal mat collected from a sulfurous spring located in Santa Maria Incaldana (Mondragone, Campania Region, southern Italy). The isolate is Gram-positive, ferments several carbohydrates and has motile, rod-shaped cells that do not sporulate. The isolate grows at pH 6.5-9.5 and in 5-20% NaCl. On the basis of 16S rRNA gene sequence similarity, the strain was shown to belong to the genus Oceanobacillus; strain 20AG(T) showed 96.6% 16S rRNA gene sequence similarity to the type strain of Oceanobacillus iheyensis, DSM 14371(T), and 99.5% similarity to Oceanobacillus oncorhynchi NCIMB 14022(T). Levels of DNA-DNA relatedness between strain 20AGT and 0. iheyensis DSM 14371(T) and 0. oncorhynchi NCIMB 14022(T) were respectively 29.4 and 59.0%. The G + C content of the DNA of strain 20AG(T) was 40.1 mol%. The predominant respiratory quinone was MK-7, phosphatidylglycerol and phosphatidylcholine were the predominant polar lipids and minor phospholipids were also detected. ai-C14:0, ai-C15:0 and i-C15:0 were the major fatty acids. Strain 20AG(T) accumulated osmolytes and produced exopolysaccharide. On the basis of phenotypic characteristics, phylogenetic data and DNA-DNA relatedness data, isolate 20AG(T) should be designated as the type strain of a subspecies of Oceanobacillus oncorhynchi, for which the name Oceanobaciflus oncorhynchi subsp incaldanensis subsp. nov. is proposed. The type strain is 20AG(T) (= DSM 16557(T) = ATCC BAA-954(T)).