Exiguobacterium algae sp. nov. and Exiguobacterium qingdaonense sp. nov., two novel moderately halotolerant bacteria isolated from the coastal algae

Two Gram-stain-positive, facultatively anaerobic, rod-shaped bacterial strains, S126(T) and S82(T), were isolated from coastal algae of China. Strains S126(T) and S82(T) are halotolerant and could grow in the presence of 0-13% NaCl and 0-14% NaCl, respectively. The two strains shared 98.9% 16S rRNA gene sequence similarity with each other and 93.4-99.8% similarity with type strains of Exiguobacterium species. The major fatty acids (> 10%) of strains S126(T) and S82(T) were iso-C-17:0, iso-C-13:0, anteiso-C-13:0 and iso-C-15:0. The predominant quinones of strains S126(T) and S82(T) were MK-7 and MK-8. The polar lipid profiles of strain S126(T) and S82(T) contained diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The cell-wall peptidoglycans of both strains S126(T) and S82(T) were of the A3 alpha L-Lys-Gly type. The average nucleotide identity (ANI) and average nucleotide index (AAI) between strains S126(T) and S82(T) and type strains of Exiguobacterium species were all below the thresholds to discriminate bacterial species, indicating that they constitute two novel species in the genus Exiguobacterium. Based on polyphasic taxonomy characterization and genomic aspects, the names Exiguobacterium algae sp. nov. and Exiguobacterium qingdaonense sp. nov. are proposed for the two novel species, with type strains being S126(T) (= CGMCC 1.17116(T) = KCTC 43079( T)) and S82(T) (= CGMCC 1.17115(T) = KCTC 43078(T)), respectively.