Sphingobacterium olei sp. Nov., isolated from oilcontaminated soil

Abstract

A Gram-stain-negative, rod-shaped, non-motile and non-spore-forming bacterium, designated HAL-9T, was isolated from oilcontaminated soil in Daqing oilfield, Heilongjiang Province, PR China. Strain HAL-9T was able to degrade quizalofop-p-ethyl and diclofop-methyl. Growth was observed at 10–35 °C (optimum, 30 °C), pH 6.0–10.0 (optimum, pH 7.0) and salinity of 0 %–5.0% (w/v; optimum 1.0 %). The results of phylogenetic analysis based on the 16S rRNA gene indicated that strain HAL-9T belongs to the genus Sphingobacterium and showed the highest sequence similarity (98.3 %) to Sphingobacterium alkalisoli Y3L14T, followed by Sphingobacterium mizutaii DSM 11724T (95.1 %) and Sphingobacterium lactis DSM 22361T (95.1 %). Menaquinone-7 (MK-7) was the only isoprenoid quinone. The predominant cellular fatty acids were summed feature 3 (C16:1ω7c and/or C16:1ω6c), iso-C15:0 and iso-C17:0 3-OH. The major polar lipids were phosphatidylethanolamine, three phosphoglycolipids and three unidentified lipids. The draft genome of strain HAL-9T was 5.41 Mb. The G+C content of strain HAL-9T was 40.6mol%. Furthermore, the average nucleotide identity and in silico DNA–DNA hybridization values between strain HAL-9T and S. alkalisoli Y3L14T were 86.2% and 32.8 %, respectively, which were below the standard thresholds for species differentiation. On the basis of phenotypic, genotypic and phylogenetic evidence, strain HAL-9T represents a novel species in the genus Sphingobacterium, for which the name Sphingobacterium olei sp. nov. is proposed. The type strain is HAL-9T (=ACCC 61581T=CCTCC AB 2019176T=KCTC 72287T).