Alkalibacillus silvisoli sp. nov., an alkaliphilic moderate halophile isolated from non-saline forest soil in Japan

Abstract

Two alkaliphilic, moderately halophilic bacteria, designated BM2(T) and HN2, were isolated from non-saline forest soil in Japan. The cells of strain BM2(T) were motile, aerobic, rod-shaped and Gram-positive. The peptidoglycan was of the A1gamma type, and the diamino acid was meso-diaminopimelic acid. Growth was observed at NaCl concentrations between 5.0 and 25.0 % (w/v) (the optimum being 10.0-15.0 %, w/v), at pH 7.0-10.0 (optimum, pH 9.0-9.5) and at 20-50 degrees C. The predominant isoprenoid quinone was MK-7. The major cellular fatty acids were iso-C(15 : 0) and anteiso-C(17 : 0). The G+C content of total DNA of strain BM2(T) was 37.0 mol%. Phylogenetic analysis of the 16S rRNA gene sequence showed that strain BM2(T) was most closely related to Alkalibacillus haloalkaliphilus DSM 5271(T) (98.0 % sequence similarity). DNA-DNA hybridization results indicated low levels of relatedness between strain BM2(T) and A. haloalkaliphilus JCM 12303(T) (23 and 16 % reciprocally), Alkalibacillus filiformis JCM 13893(T) (25 and 21 %) and Alkalibacillus salilacus JCM 13894(T) (27 and 19 %). On the basis of the phylogenetic and phenotypic characteristics, strain BM2(T) represents a novel species, for which the name Alkalibacillus silvisoli sp. nov. is proposed. The type strain is BM2(T) (=JCM 14193(T)=DSM 18495(T)).