莠去津降解菌HB-5的最佳产酶培养基及发酵条件

从农药厂废水中分离到一株降解莠去滓的节杆菌(Arthrobacter sp.)HB-5,以从该菌中提取到的降解酶对莠去津的降解率为指标,进行最佳产酶培养基及发酵条件的优化研究,对其产酶量进行了评价.通过正交试验和均匀试验,对细菌HB-5的发酵培养基进行了优化研究.运用SAS软件进行结果分析,所获优化培养基配方为:蔗糖3.0g·L-1,莠去津0.38g·L-1,K2HPO40.5g·L-1,KH2PO41.2 g·L-1,MgSO4·7H2O 1.2g·L-1,NaCl 0.1g·L-1,微量元素溶液3.8mL·L-1.得到菌株培养的最佳优化条件为:菌株发酵液培养时间为48h.接种量为2%,发酵液初始pH值为9,250mL三角瓶中装液量为80mL经优化后,降解酶对莠去津的降解率(91.64%)比原培养基(40.67%)提高了125%.

Optimized culture medium and fermentation conditions for enzyme production by the atrazine-degrading bacterium HB-5

An atrazine degrading bacterium (Arthrobacter sp.) HB-5, was isolated in our laboratory from pesticide waste water. The optimum fermentation conditions and fermentation culture medium of HB-5 were selected by uniform experimental design and orthogonal experimentation, and the amount of enzyme produced by HB-5 was estimated from the atrazine degradation rate. The experimental results were analyzed by the SASsystem. The ideal composition of culture medium of HB-5 included saccharose 3.0 g·L^-1, atrazine 0.38 g·L^-1, K₂HPO₄ 1.2 g·L^-1, K₂HPO₄ 0.5 g·L^-1, MgSO₄· 7H₂O_1.2 g·L^-1, NaCl 0.1 g·L^-1,microelements 3.8 mL·L^-1. The optimum culture conditions of HB-5 were: culture time 48 h, inoculum size 2%, initial pH_9.0 and amount of culture medium 80 mL. The degradation rate of atrazine by the optimum fermentation liquid reached up to 91.64%, and increased 125% over the original culture medium (40.67%).