己烯雌酚降解菌固定化条件优化及其降解性能

Immobilization and degradation performance of diethylstilbestrol-degrading bacteria S(Serratia sp.)

以海藻酸钠为包埋剂,制备了己烯雌酚（DES）降解菌株S（Serratia sp.）的固定化菌剂,通过正交试验确定了菌株S的最佳固定化条件：海藻酸钠质量分数为4%,菌悬液与海藻酸钠重量比为1：2,CaCl_2质量分数为4%,交联时间为6h.菌株S的固定化菌剂比游离菌株更有优势;7d时,固定化菌株S对无机盐培养基中DES的去除率为83.84%,较游离菌株高22.84%.优化了固定化菌株S对溶液中DES的处理条件：固定化菌株S接入量为300g/L,初始底物浓度为20～40mg/L.固定化菌株S对DES浓度为40.01,37.90,33.52μg/L 3个排污口污水中DES的去除率分别达90.0%,96.0%,96.7%.利用固定化菌株处理实际污水中DES等雌激素具有应用潜力.

Diethylstilbestrol（DES）-degrading bacteria S（Serratia sp.） was immobilized using sodium alginate as the embedding agent.The optimum immobilization conditions,determined through orthogonal test,were as follows：4% sodium alginate,bacteria：sodium alginate 1：2,4% CaCl_2 and 6h crosslinking time.The DES degradation performance of immobilized strain S was apparently superior to that of free strain.The degradation ratio of DES by immobilized strain S was 83.84%,which was 22.84% higher than that by free strain S under laboratory culture conditions.The optimum inoculation of immobilized strain S was 300g/L,and the optimum initial DES concentration was 20～40mg/L.Three water samples were collected from sewage outfalls with DES concentrations of 40.01,37.90 and 33.52μg/L,respectively.Immobilized strain S was added to these water samples,and 90.0%,96.0% and 96.7% of DES were removed by immobilized strain S after 7d.Results of this investigation provide a new available technique for estrogen removal from polluted water systems.