Anoxybacillus amylolyticus sp nov., a thermophilic amylase producing bacterium isolated from Mount Rittmann (Antarctica)

A new thermophilic spore-forming strain MR3C(T) was isolated from geothermal soil located on Mount Rittmann in Antarctica. Strain MR3C(T) was Gram-positive, rod-shaped, occurring in pairs or filamentous. Growth was observed between 45 and 65 degrees C (optimum 61 degrees C) and at pH 5.0-6.5 (optimum pH 5.6). It was capable of utilizing galactose, trehalose, maltose and sucrose. The microorganism produced an exopolysaccharide and synthesized an extracellular constitutive amylolytic activity. The G+C content of DNA was 43.5 mol%. On the basis of 16S rRNA gene sequence similarity, strain MR3C(T) was shown to be related most closely to Anoxybacillus species. Chemotaxonomic data (major isoprenoid quinone-menaquinone-7; major fatty acid-iso-C15:0 and iso-C17:0) supported the affiliation of strain MR3C(T) to the genus Anoxybacillus. The results of DNA-DNA hybridization, physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain MR3C(T) from the validly published Anoxybacillus species. MR3C(T) therefore represents a new species, for which the name Anoxybacillus amylolyticus sp. nov., is proposed, with the type strain MR3C(T) (= ATCC BAA-872(T) = DSM 15939(T) = CIP 108338(T)). (c) 2005 Elsevier GmbH. All rights reserved.