Pseudomonas Saliphila sp. nov., a Bacterium Isolated from Oil-Well Production Water in Qinghai Oilfield of China.

Strain 16W4-4-3 was isolated from the oil-well production water in Qinghai Oilfield, China. Cells were Gram-stain-negative, rod-shaped, catalase- and oxidase-positive, facultatively anaerobic and motile by single polar flagellum. The 16S rRNA gene sequences of strain 16W4-4-3 showed the highest similarities with Pseudomonas profundi M5 (98.8%), P. pelagia CL-AP6 (98.0%), P. salina XCD-X85 (97.7%), and P. sabulinigri J64 (97.5%). The phylogenetic trees based on multilocus sequence analyses with concatenating 16S rRNA, gyrB, rpoD and rpoB genes suggested that this strain should be affiliated to the genus Pseudomonas but remotely related from other species. In addition, whole genome analyses revealed that the digital DNA-DNA hybridization values and average nucleotide identities of strain 16W4-4-3 against its close relatives were all below 28.8% and 86.5%, respectively. Furthermore, the isolate had totally different whole cell protein profile as compared to those of other species. Major fatty acids were summed feature 8 (Cω7c and/or Cω6c), C, summed feature 3 (Cω7c and/or Cω6c) and Ccyclo. Major isoprenoid quinone was ubiquinone (Q-9), and major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylethanolamine. The DNA G + C content was 58.5 mol%. Therefore, phenotypic, phylogenetic, genomic, chemotaxonomic, and proteomic traits showed that the isolate represented a novel species of the genus Pseudomonas, the name Pseudomonas saliphila sp. nov. is proposed. Type strain is 16W4-4-3 (= CGMCC 1.13350 = KCTC 72619).