Planococcus lenghuensis sp. nov., an oil-degrading bacterium isolated from petroleum-contaminated soil

A Gram-staining-positive and aerobic coccus with the ability to degrade petroleum bacterium, designated Y42^T, was isolated from the Lenghu oil field located in the northern margin of the Qaidam Basin. Phylogenetic and signature nucleotides analyses revealed that strain Y42^T belongs to the genus Planococcus. The multiple sequence alignments of 16S rRNA and housekeeping genes showed that strain Y42^T formed a distinct lineage with the other Planococcus clade. The average nucleotide identity (ANI) and DNA-DNA hybridization values (DDH) between strain Y42^T and the reference strains were 69.5-70.1 and 19.4-21.7%, respectively, which values were below the threshold for species delineation. The major fatty acids of strain Y42^T were anteiso-C_15:0. The respiratory quinone was MK-7 (71.8%) as the predominant menaquinone followed the MK-6 (28.2%) and the cell-wall hydrolysates contained LL-diaminopimelic acid. The polar lipid was composed of diphosphatidyl glycerol, phosphatidyl glycerol, phosphoglycolipid, aminophospholipid and four unidentified lipids. The peptidoglycan type was A4α (L-Lys-D-Glu). The strain Y42^T possessed larger genome (approximately 4 MB) and revealed obvious differences for the abundance of the COG categories compared with the other Planococcus bacteria. Also, the strain Y42^T also possessed more unique orthologous proteins. The structural characteristics of the strain Y42^T genome provided a competitive advantage for better survival in petroleum-polluted environments. Combined with the 16S rRNA gene and genome sequence, phenotypic as well as chemotaxonomic characterisations, strain Y42^T is considered to represent a novel species of the genus Planococcus, for which the name Planococcus lenghuensis sp. nov. be proposed. The type strain is Y42^T (= CGMCC 1.15921^T = JCM 32719^T).