Three Gram-variable, moderately halophilic, motile, endospore-forming rods, designated P2-C2T, P3-H5T and P3-B8, were isolated from marine sediment of the Southwest Indian Ocean by using the microfluidic streak plate method. Phylogeny based on 16S rRNA gene sequences showed that strains P2-C2T and P3-H5T formed a robust cluster within the genus Virgibacillus and exhibited 16S rRNA gene similarity levels of 95.3-96.8 and 94.9-96.3 % to the type strains of Virgibacillus species, respectively. The 16S rRNA gene similarity between P2-C2T and P3-H5T was 97.6 %. Strain P3-B8 has an identical 16S rRNA gene sequence to strain P3-H5T. For all the novel strains, the predominant cellular fatty acids were anteiso-C15 : 0 and anteiso-C17 : 0, the main menaquinone was MK-7, and the polar lipid profiles contained diphosphatidylglycerol and phosphatidylglycerol. The genomic DNA G+C contents of strains P2-C2T, P3-H5T and P3-B8 were 38.3, 37.3 and 37.5 mol%, respectively. Combined data from phenotypic and genotypic studies demonstrated that strains P2-C2T and P3-H5T/P3-B8 are representatives of two different novel species of the genus Virgibacillus, for which the name Virgibacillus indicus sp. nov. and Virgibacillusprofundi are proposed. The type strains are P2-C2T (=CGMCC 1.16138T=NBRC 113014T) and P3-H5T (=CGMCC 1.16139T=NBRC 113015T).
Keywords: Virgibacillus; Virgibacillus indicus sp. nov.; Virgibacillus profundi sp. nov.; droplet microfluidics; microfluidic streak plate; polyphasic taxonomy.