Brevibacillus humidisoli sp. nov., a moderately thermoalkaliphilic and halotolerant species isolated from riverside soil

A Gram-stain-positive, aerobic, rod-shaped, motile, and endospore-forming bacterial strain designated MMS20-4M-10-Y was isolated from riverside soil and subjected to taxonomic characterization. Strain MMS20-4M-10-Y was moderately thermophilic, alkaliphilic and halotolerant, as the strain grew at 25-50 °C (optimum, 45 °C), at pH 7.0-10.0 (optimum, pH 8.0) and in the presence of 0-6 % NaCl (optimum, 0 %). Analysis of 16S rRNA gene sequences indicated that MMS20-4M-10-Y fell into a phylogenetic cluster belonging to the genus . Strain MMS20-4M-10-Y showed the highest 16S rRNA gene sequence similarity to SCSIO 07484 (96.7 %). Based on the reults of orthologous average nucleotide identity analysis, MMS20-4M-10-Y was again mostly related to SCSIO 07484 with 78.0 % identity, which also shared the highest average nucleotide identity of 68.0 %. In contrast, the digital DNA-DNA relatedness analysis indicated that DSM 2895 was the closest species with 29.5 % similarity. The genome-based analyses indicated that all compared species showed low genomic relatedness with MMS20-4M-10-Y . The major fatty acids of the strain were anteiso-C , iso-C , iso-C and iso-C , the major respiratory quinone was MK-7, the diagnostic polar lipids were phosphatidyl- -methylethanolamine, diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol, and diagnostic cell-wall diamino acid was -diaminopimelic acid, which was consistent with the general chemotaxonomic features of the genus. The total length of the genome was 4.91 Mbp and the DNA G+C content was 51.8 mol%. Based on both phenotypic and phylogenetic evidence, strain MMS20-4M-10-Y should be classified as representing a novel species of the genus , for which a name sp. nov. (type strain=MMS20-4M-10-Y =KCTC 43333 =LMG 32359 ) is proposed.