嘧菌酯降解菌的分离及降解动力学分析

Isolation and Molecular Identification of Azoxystrobin Degrading Bacteria

由于嘧菌酯的广泛使用和残留对环境中非靶标生物有氧化胁迫作用,所以其危害越来越引起人们的关注。该文驯化筛选出一株高效降解嘧菌酯的菌株,并探讨了其修复嘧菌酯污染的最适条件。利用嘧菌酯为唯一碳源筛选能有效降解嘧菌酯的菌株G7,对菌株进行形态生理生化特征试验及16S r RNA基因同源性分析确定该菌株的系统发育学地位。通过响应面分析法和正交试验确定菌株G7外界和液体降解最优条件。经过优化培养基和外界培养条件后得到48 h后在K2HPO42 810 mg/L,KH_2PO_4781 mg/L,NH_4NO_31 000 mg/L,(NH_4)_2SO_4821.39 mg/L,Na Cl 825.16 mg/L,Mg SO_4·7H_2O 1 000 mg/L,嘧菌酯168.86 mg/L,p H为7.25,温度37℃,摇床转速为175 r/min的条件下降解率最高为84.17%,并确定了G7菌株为施氏假单胞菌(Pseudomonas stutzeri),通过降解动力学建立了降解过程的数学模型。

Extensive use of azoxystrobin and the oxidative stress effect of its residue on non-target organism in the environment have caused more and more public concerns. By domesticating and selecting an effective strain of azoxystrobin,this article has explored the best fit condition to recover azoxystrobin pollution. Azoxystrobin was used as the sole carbon source in the degradation of azoxystrobin strain named G7. To determine the phylogenetic status of this strain, the strain＇s morphological, physiological, and biochemical characteristic experiment and 16 s r RNA homology analysis were carried out.Both response surface analysis and orthogonal experiment were used to optimize the external and liquid degradation conditions of strain G7. 48 hours later after optimizing the medium and external culture conditions, the maximum degradation rate reached 84.17% under the condition of K_2HPO_42 810 mg/L, KH_2PO_4781 mg/L, NH_4NO_31 000 mg/L,（NH_4）_2SO_4821.39mg/L, Na Cl 825.16 mg/L, Mg SO_4·7H_2O 1 000 mg/L, azoxystrobin 168.86 mg/L, p H 7.25, at 37 ℃, and table concentrator rate at 175 r/min.The strain G7 was identified as Pseudomonas stutzeri, the dynamic model of the degradation process was also built.