Salegentibacter lacus sp. nov. and Salegentibacter tibetensis sp. nov., isolated from hypersaline lakes on the Tibetan Plateau

Two Gram-stain-negative, catalase- and oxidase-positive, rod-shaped and non-motile strains (LM13S(T) and JZCK2(T)) were isolated from hypersaline lakes in China. The colonies of both strains were yellow-pigmented and convex. Both strains could grow at 4-34 degrees C, pH 6.5-9.0 and with 1.0-13.0 % (w/v) NaCl. Comparisons based on 16S rRNA gene sequences showed that strains LM13S(T) and JZCK2(T) share less than 98.3% similarity with species of the genus Salegentibacter. The phylogenetic tree reconstructed based on 16S rRNA gene sequences also showed that Salegentibacter species are the most closely related neighbours of strains LM13S(T) and JZCK2(T). The sequenced draft genome sizes of strains LM13S(T) and JZCK2(T) are 4.06 and 4.22 Mbp with G+C contents of 37.0 and 37.8mol%, respectively. The phylogenomic tree reconstructed using the Up-to-date Bacterial Core Gene set pipeline also demonstrated that both strains belong to the genus Salegentibacter. The calculated pairwise average nucleotide identity values and digital DNA-DNA hybridization values between strains LM13S(T) and JZCK2(T) and Salegentibacter species were less than 86.4 and 32.0%, respectively. The respiratory quinone in both strains was MK-6. Their major fatty acids were iso-C-12:0, iso-C-14:0, C-15:1 omega 10c, iso-C-15:0, anteiso-C-15:0, iso-C-16:0 and C-17:1 omega 10c. Their major polar lipids included phosphatidylethanolamine, one unidentified lipid and one unidentified aminolipid, but strain LM13S(T) also contained one more unidentified aminolipid, one more unidentified lipid and one unidentified phospholipid. Combining the above descriptions, strains LM13S(T) and JZCK2(T) should represent two independent novel species of the genus Salegentibacter, for which the names Salegentibacter lacus sp. nov. (type strain LM13S(T)=GDMCC 1.2643(T)=KCTC 82861(T)) and Salegentibacter tibetensis sp. nov. (type strain JZCK2(T)=GDMCC 1.2621(T)=KCTC 82862(T)) are proposed.

Automated summary

Two new species of Gram-stain-negative bacteria with yellow colonies were isolated from hypersaline lakes in China.