Biodegradation of Crude Oil Under Low Temperature by Mixed Culture Isolated from Alpine Meadow Soil

Abstract

Petroleum hydrocarbons have been worldwide concern contaminants because of their mutagenicity and carcinogenicity. The potential biodegradation of petroleum hydrocarbons at low temperatures is important for petroleum contamination remediation in cold region. In this study, a mixed cold-adapted bacteria flora JY, including seven petroleum-degrading strains (B1, H1, H2, H3, R1, R2, and S), was isolated from Alpine Meadow soil. Based on their 16S rRNA sequence analysis, B1, R1, and H3 were identified as Arthrobacter sp.; R2, S, H1, and H2 were identified as Rhodococcus sp., Pseudomonas sp., Stenotrophomonas sp., and Sphingobacterium sp., respectively. The mixed flora demonstrated 53.68% of total petroleum hydrocarbons (TPH) removal of the contaminated water (1 g oil L-1) after 30 days of incubation under 10 °C. In the degradation process, alkanes were more preferred to be degraded by JY than polycyclic aromatic hydrocarbons (PAHs) and other polar component. During this period, the abundant bacteria in the flora were transformed from alkane degraders of Rhodococcus sp. and Sphingobacterium sp. to PAH degraders of Pseudomonas sp. and sheltered Arthrobacter sp. This study verified that a cold-adapted mixed culture JY isolated from alpines meadow soil was capable in degrading TPH under low temperature through flora cooperation.