Construction of highly efficient crude oil degrading bacteria and synergistic degradation performance on aromatic hydrocarbon compound naphthalene

Abstract:

[Background] As a type of mixed organic compound, crude oil can cause serious harm to humans and the environment once oil pollution occurs. [Objective] Crude oil degrading bacteria from contaminated soil in Xinjiang were isolated and screened to provide data support and technical reference for the bioremediation of crude oil contaminated soil. [Methods] Using crude oil as the sole carbon source, a total of 123 individual strains were isolated from crude oil through enrichment culture and screening. Thirty different strains were selected according to the morphology of the colonies, and their species were determined by 16S rRNA gene sequencing to construct a phylogenetic tree. Highly efficient crude oil degrading bacteria were screened out through crude oil degradation experiments, and the naphthalene, a representative compound of aromatic hydrocarbons, as the sole carbon source to screen high efficient degradation strains. [Results] Five strains of highly efficient crude oil degrading bacteria were isolated; these strains showed degradation rates higher than 85%. The strains capable of degrading naphthalene, salicylic acid, and catechol were obtained and applied for naphthalene degradation at a 1:1:1 inoculation ratio. The degradation rate of naphthalene increased from 60.74% to 89.40%, thus proving that division of labor cooperation between strains could improve their degradation efficiency for organic matter. [Conclusion] The strains obtained from screening enrich the crude oil degrading microbial species bank, and the observed division of labor cooperation among different microbial strains provides new ideas for the degradation of crude oil pollutants. The results also offer a reference for further research on crude oil pollution control.