高效石油降解菌群的构建及对芳香烃化合物萘的协同降解性能

【背景】石油作为一类混杂有机化合物,一旦产生污染就会对人类和环境造成严重的危害。【目的】从新疆石油污染土壤中分离筛选石油降解菌,为石油污染土壤的生物修复提供数据支持及技术参考。【方法】以石油为唯一碳源,通过富集培养、筛选分离得到123株单菌,根据菌落形态挑选出30个不同形态菌株,通过16S rRNA基因序列确定其种属,构建系统发育树;通过原油降解实验筛选出高效石油降解菌,以芳香烃的标志化合物萘为唯一碳源筛选出高效降解菌株,并分别筛选可降解水杨酸、邻苯二酚的菌株。【结果】分离筛选出5株高效石油降解菌,降解率高于85%;萘、水杨酸和邻苯二酚降解菌株各获得一株,将3种菌株按照1:1:1的接种比例对萘进行降解,萘的降解率从单菌60.74%提升到89.40%,菌株间的分工协作可以提高有机物的降解效率。【结论】筛选得到的菌株丰富了石油降解微生物菌种库,不同微生物菌株之间的分工协作为石油污染物的降解提供了新思路,为进一步研究石油污染治理提供参考。

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

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.