Bacillus paraflexus sp. nov., isolated from compost

A Gram-stain-positive, rod-shaped, endospore-forming, aerobic bacterium capable of growing at 15–42 °C (optimum 30 °C) and at pH 5–11 (optimum pH 7) was isolated from compost. Its taxonomic position was deduced using a polyphasic approach and the strain was designated RC2^T. 16S rRNA gene sequence analysis showed that the isolate belongs to the division Firmicutes, forming a clade within the cluster containing Bacillus flexus IFO 15715^T, and showed highest similarity to B. flexus IFO 15715^T (98.1 %). The cell wall contained meso-diaminopimelic acid as the diagnostic diamino acid. The major cellular fatty acids of the novel strain were iso-C_15:0 (36.83 %), anteiso-C_15:0 (49.19 %) and C_16:0 (5.19 %). DNA–DNA hybridization between strain RC2^T and B. flexus DSM 1320^T showed a level of relatedness of 54.5 %. The polar lipid profile of strain RC2^T showed the presence of phosphatidylglycerol, diphosphatidylglycerol and phosphatidylethanolamine. The predominant isoprenoid quinone was MK-7 and the G+C content of strain RC2^T was 37.6 mol%. On the basis of phenotypic characteristics, phylogenetic analysis and the results of biochemical and physiological tests, strain RC2^T was clearly distinguished from closely related members of the genus, and the strain is assigned to a novel species, for which the name Bacillus paraflexus sp. nov. is proposed. The type strain is RC2^T ( = MTCC 9831^T = MCC 2100^T = KCTC 13724^T = CCM 7754^T).