Description of Cytobacillus Mangrovibacter sp. nov., and Cytobacillus Spartinae sp. nov., Isolated from Mangrove Sediment.

Abstract

Two Gram-stain-positive, aerobic, rod-shaped, and motile strains FJAT-53684 ^T and FJAT-54145 ^T were isolated from the mangrove sediment. They optimally grew at pH 8.0 and could tolerate NaCl up to 5% (w/v). The optimum temperature for growth of strains FJAT-53684 ^T and FJAT-54145 ^T were 35 and 40 ºC, respectively. The 16S rRNA gene sequence similarity between FJAT-53684 ^T and FJAT-54145 ^T was 97.1%. Both strains showed the highest 16S rRNA gene sequence similarity to the Cytobacillus species. Menaquinone-7 was the only respiratory quinone present in both strains. The major fatty acids (≥ 10%) in strain FJAT-53684 ^T were iso-C_14:0, anteiso-C_15:0, iso-C_15:0, and iso-C_19:0, while strain FJAT-54145 ^T consist of iso-C_14:0, iso-C_15:0, iso-C_19:0, iso-C_16:0, and C_16:1 ω7c alcohol. The polar lipids present in both strains were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, unidentified lipid, unidentified phospholipid, and phosphatidylinositol. Their average nucleotide identity and digital DNA-DNA hybridization values were below the threshold values (95% and 70%, respectively) for species delineation. Based on the above results, strains FJAT-53684 ^T and FJAT-54145 ^T represent two novel species of the genus Cytobacillus, for which the names Cytobacillus mangrovibacter sp. nov., and Cytobacillus spartinae sp. nov., are proposed. The type strains are FJAT-53684 ^T (= JCM 35618 ^T = GDMCC 1.3071 ^T), and FJAT-54145 ^T (= JCM 35621 ^T = GDMCC 1.3079 ^T).