Planococcus Daihaiensis sp. nov. Isolated from the Lake Water in Daihai

A novel aerobic, Gram-stain-positive, non-motile, non-spore-forming, short rod-shaped strain X10-3^T, was isolated from Daihai Lake, Inner Mongolia, China. The strain formed circular, smooth, transparent, orange-colored colonies with convex elevation and entire margins, which measured approximately 1.0-4.0 mm in diameter after 48 h of incubation on Luria-Bertani agar at 32 °C. The strain was able to grow at pH levels between 6.5 and 9.0 (optimal at 7.5-8.0), temperatures from 4 to 40 °C (optimal at 37 °C), and in 0-13% (optimal at 2-3%, w/v) NaCl. The complete genome of strain X10-3^T comprises 3,244,194 bp with a DNA G + C content of 45.9%. Phylogenetic analysis revealed the closest relationship to members of the genus Planococcus, showing 16S rRNA gene sequence similarities of 99.2% with P. salinarum DSM 23820^T, 98.8% with P. wigleyi Sa1BUA13^T, 98.6% with P. koreense JG07^T, and 98.6% with P. halotolerans SCU63^T. The average nucleotide identity between strain X10-3^T and the species within the genus Planococcus fell below the species delineation thresholds of 95%, and the digital DNA-DNA hybridization values were lower than 70%. Chemotaxonomic analysis revealed that the predominant cellular fatty acids of strain X10-3^T were anteiso-C_15:0 and C_16:1 ω7c alcohol. The primary cellular polar lipids included phosphatidylethanolamine, phosphatidylglycerol, and diphosphatidylglycerol, while the predominant isoprenoid quinones were menaquinone-8 and menaquinone-7. Based on these comprehensive analyses, strain X10-3^T represents a new species of the genus Planococcus, for which the name Planococcus daihaiensis sp. nov. is proposed. The type strain is X10-3^T (= CGMCC 1.60163^T = KCTC 43688^T).