Aeribacillus composti sp nov., a thermophilic bacillus isolated from olive mill pomace compost

A Gram-stain-positive, aerobic, endospore-forming, thermophilic bacterium, strain N.8(T), was isolated from the curing step of an olive mill pomace compost sample, collected at the Composting Experimental Centre (CESCO, Salerno, Italy). Strain N.8(T), based on 16S rRNA gene sequence similarities, was most closely related to Aeribacillus pallidus strain H12(T) (=DSM 3670T) (99.8% similarity value) with a 25% DNA-DNA relatedness value. Cells were rod-shaped, non-motile and grew optimally at 60 degrees C and pH 9.0, forming cream colonies. Strain N.8 was able to grow on medium containing up to 9.0% (w/v) NaCl with an optimum at 6.0% (w/v) NaCl. The cellular membrane contained MK-7, and C-16 : 0 (48.4 %), iso-C-17 : 0 (19.4 %) and anteiso-C-17 : 0 (14.6 %) were the major cellular fatty acids. The DNA G+C content was 40.5 mol%. Based on phenotypic characteristics, 16S rRNA gene sequences, DNA-DNA hybridization values and chemotaxonomic characteristics, strain N.8(T) represents a novel species of the genus Aeribacillus, for which the name Aeribacillus composti sp. nov. is proposed. The type strain is N.8(T) (=KCTC 33824(T)=JCM 31580(T)).