Microbulbifer zhoushanensis sp. nov., Microbulbifer sediminum sp. nov. and Microbulbifer guangxiensis sp. nov., three marine bacteria isolated from a tidal flat

Three strains, TT30(T), TT37(T) and L3(T), were isolated from tidal flat samples. Cells were Gram- stain-negative, non-motile and rod shaped. Cells of strains TT30(T) and TT37(T) were able to grow in a medium containing 1.0-15.0 % (w/v) NaCl (optimum, 3.0 and 4.0 %, respectively), and cells of strain L3(T) was able to grow in a medium containing 1.0-10.0 % (w/v) NaCl (optimum, 1.0 %). Growth of the three strains was observed at pH 6.0-10.0 and at 10-40 degrees C. Strains TT30(T), TT37(T) and L3(T) showed the highest similarity to Microbulbifer hydrolyticus DSM 11525(T) (97.7 %), M. yueqingensis CGMCC 1.10658(T) (98.0 %) and M. elongatus DSM 6810(T) (97.9 %), respectively. Results of phylogenetic analyses indicated that the three isolates represented two distinct line-ages within the genus Microbulbifer. The DNA G+C contents of strains TT30(T), TT37(T) and L3(T) were 61.3, 60.9 and 60.2%, respectively. The average nucleotide identity and in silico DNA-DNA hybridization values among strains TT30(T), TT37(T) and L3(T) and the reference strains were 84.4-87.4 and 19.6-28.9 %, respectively. Differential phenotypic properties, chemotaxonomic differ-ences, phylogenetic distinctiveness, together with the genomic data, demonstrated that strains TT30(T), TT37(T) and L3(T) represent novel species of the genus Microbulbifer, which are named Microbulbifer zhoushanensis sp. nov. (TT30(T)=KCTC 92167(T=)MCCC 1K07276(T)), Microbulbifer sediminum sp. nov. (TT37(T)=KCTC 92168(T)=MCCC 1K07277(T)) and Microbulbifer guangxiensis sp. nov. (L3(T)=KCTC 92165(T)=MCCC 1K07278(T)).

Automated summary

Three strains, TT30(T), TT37(T) and L3(T), were isolated from tidal flat samples. These strains were Gram-stain-negative, non-motile and rod shaped. They were able to grow in medium containing varying concentrations of NaCl and at different pH and temperature ranges.