苯酚对菲高效生物降解的共代谢强化作用机制

MECHANISM OF CO-METABOLISM ENHANCEMENT OF EFFICIENT BIODEGRADATION OFPHENANTHRENE BY PHENOL

从好氧污泥中筛选出了1株可高效降解菲的菌株。首先探究了该菌株以不同碳源为共基质时对菲的降解特性。结果表明:以80 mg/L苯酚为共基质有效促进了30 mg/L菲的快速降解,菲降解率高达95.35%,与不加苯酚的非共代谢组相比,增加了20.33%,同时苯酚得以充分矿化;进一步从细胞生理响应和相关酶活性表达方面分析了该菌株以苯酚为共基质下的共代谢强化作用机制,发现共代谢体系下生物量明显增加,微生物活性显著提升,从而促进了胞外聚合物(EPS)中蛋白和多糖的大量分泌以及细胞膜表面官能团的改变;相比于非共代谢体系,共代谢体系促使脱氢酶(DHA)活性和双加氧酶(C23O)活性提前12 h表达,且活性分别提升了0.17~3.37,0.84~1.71倍。因此,以苯酚为共基质的共代谢体系可有效提高菲的降解率,对实现芳烃类物质高效降解具有重要意义。

A strain that could efficiently degrade phenanthrene was isolated from the aerobic sludge.Firstly,the degradation characteristics of phenanthrene with different carbon sources as co-substrates were explored.The results showed that the degradation rate of 30 mg/L phenanthrene reached 95.35%in the co-metabolism system with 80 mg/L phenol as a co-substrate.Compared with the non-co-metabolism system without phenol,the degradation rate of phenanthrene increased by 20.33%,and phenol was also mineralized.The co-metabolism enhancement mechanism of the strain with phenol as a co-substrate was further analyzed based on the cells’physiological response and the related enzymatic expression.It was found that biomass and microbial activity increased significantly,which promoted the secretion of proteins and polysaccharides in extracellular polymeric substances(EPS).And the functional groups of EPS also were changed in the co-metabolism system.In addition,compared with the non-co-metabolism system,the co-metabolism system could advance the expression of dehydrogenase(DHA)activities and dioxygenase(C23O)activities by 12 h,and the activities respectively increased by 0.17 to 3.37 times and 0.84 to 1.71,respectively,times during the degradation process.Therefore,the co-metabolism system with phenol as a co-substrate could effectively improve the degradation rate of phenanthrene,which was of great significance for the efficient degradation of aromatic hydrocarbons.