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

Abstract

A Gram-staining-positive and aerobic coccus with the ability to degrade petroleum bacterium, designated Y42T, was isolated from the Lenghu oil field located in the northern margin of the Qaidam Basin. Phylogenetic and signature nucleotides analyses revealed that strain Y42T belongs to the genus Planococcus. The multiple sequence alignments of 16S rRNA and housekeeping genes showed that strain Y42T formed a distinct lineage with the other Planococcus clade. The average nucleotide identity (ANI) and DNA-DNA hybridization values (DDH) between strain Y42T 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 Y42T were anteiso-C15:0. 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 Y42T possessed larger genome (approximately 4MB) and revealed obvious differences for the abundance of the COG categories compared with the other Planococcus bacteria. Also, the strain Y42T also possessed more unique orthologous proteins. The structural characteristics of the strain Y42T 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 Y42T 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 Y42T (= CGMCC 1.15921T = JCM 32719T).