Anoxybacillus bogrovensis sp. nov., a novel thermophilic bacterium isolated from a hot spring in Dolni Bogrov, Bulgaria

Abstract

A novel moderately thermophilic bacterium, designated strain BT 13(T), was isolated from a geothermal water source in Dolni Bogrov, near Sofia, Bulgaria. The isolate was spore-forming, Gram-positive, facultatively anaerobic, alkalitolerant and heterotrophic, and was able to ferment a wide variety of carbon sources including d-glucose, sucrose, l-arabinose, l-rhamnose, starch, sorbitol and glycogen. Strain BT 13(T) grew optimally at pH 8.0 and 65 degrees C. Intracellular amylolytic activity was registered with glucose as the main product of starch hydrolysis. Phylogenetic analysis based on the 16S rRNA gene revealed that the strain belonged to the genus Anoxybacillus, the closest relatives being Anoxybacillus flavithermus and Anoxybacillus kamchatkensis. The DNA G+C content was 44.1 mol%. The fatty acid profile with a content of iso-branched fatty acids of around 80 % of the total fatty acids is similar to that of recognized Anoxybacillus species. On the basis of genotypic differentiation and significant differences in phenotypic characteristics, it was concluded that strain BT 13(T) represents a novel species of the genus Anoxybacillus, for which the name Anoxybacillus bogrovensis sp. nov. is proposed. The type strain is BT 13(T) (=DSM 17956(T)=NBIMCC 8427(T)).