Planococcus shenhongbingii sp. nov., Planococcus shixiaomingii sp. nov. and Planococcus liqunii sp. nov., isolated from soil of the Qinghai-Tibet Plateau

Abstract

Six novel bacterial strains, designated N016T, N017, N022T, N028, N056T, and N064, were isolated from soil sampled on the Qinghai-Tibet Plateau. Cells were aerobic, orange or yellow, globular or rod-shaped, non-motile, non-spore-forming, Gram-stain-positive, catalase-positive and oxidase-negative. All the isolates were salt-tolerant and could grow in the range of 4–42 °C. Results of phylogenomic analyses based on 16S rRNA gene sequences and core genomic genes showed that the three pairs of strains (N016T/N017, N022T/N028, and N056T/N064) were closely related to the members of the genus Planococcus, and clustered with Planococcus ruber, Planococcus glaciei, and Planococcus chinensis. The digital DNA–DNA hybridization and average nucleotide identity values of the six novel strains with other members of the genus Planococcus were within the ranges of 18.7–53 % and 70.58–93.49 %, respectively, all below the respective recommended thresholds of 70.0 % and 95–96 %. The genomic DNA G+C content of the six strains ranged from 43.5 to 46.0 mol%. The major fatty acids of the six strains were anteiso-C15 : 0, iso-C14 : 0, and C16 : 1  ω7c alcohol. The predominant polar lipids of strains N016T, N022T, and N056T were diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylethanolamine. Menaquinones 7 and 8 were the respiratory quinones. The results of the above analyses indicated that the six strains represent three novel species of the genus Planococcus, for which the names Planococcus shenhongbingii sp. nov. (type strain N016T=GDMCC 1.4062T=JCM 36224T), Planococcus shixiaomingii sp. nov. (type strain N022T=GDMCC 1.4063T=JCM 36225T), and Planococcus liqunii sp. nov. (type strain N056T=GDMCC 1.4064T=JCM 36226T) are proposed.