Oceanobacillus oncorhynchi subsp. incaldanensis subsp. 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 20AGT, 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 20AGT showed 96.6 % 16S rRNA gene sequence similarity to the type strain of Oceanobacillus iheyensis, DSM 14371T, and 99.5 % similarity to Oceanobacillus oncorhynchi NCIMB 14022T. Levels of DNA-DNA relatedness between strain 20AGT and O. iheyensis DSM 14371T and O. oncorhynchi NCIMB 14022T were respectively 29.4 and 59.0 %. The G+C content of the DNA of strain 20AGT 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 20AGT accumulated osmolytes and produced exopolysaccharide. On the basis of phenotypic characteristics, phylogenetic data and DNA-DNA relatedness data, isolate 20AGT should be designated as the type strain of a subspecies of Oceanobacillus oncorhynchi, for which the name Oceanobacillus oncorhynchi subsp incaldanensis subsp. nov. is proposed. The type strain is 20AGT (=DSM 16557T = ATCC BAA-954T).