【摘要】 来自灵芝ST(Ganoderma sp.ST)的漆酶在无氧化还原介质存在时能够直接转化苯氧羧酸类除草剂2,4-D丁酯。对酶转化2,4-D丁酯的条件进行了优化,包括pH值、给酶量和反应温度。灵芝ST漆酶在pH值4.0～8.0和15～30℃的范围内均能够有效转化2,4-D丁酯(初始浓度0.5mg/L),在最适的pH值7.0、给酶量25U/L和温度30℃条件下,转化率随着酶作用时间的延长而提高,在24h左右达到最高(>99.5%)。酶活力在作用时间内稳定,并且用自来水代替缓冲液获得的转化率相当。更多还原

【Abstract】 The laccase produced by Ganoderma sp.ST,a strain newly selected by our group,was capable of transforming a phenoxy-hydroxy-acid herbicide 2,4-D butyl ester in the absence of redox mediators.The laccase-substrate system was optimized with pH,enzyme concentration and temperature.The laccase used efficiently transform 2,4-D butyl ester with 0.5 mg/L at a pH range from 4.0 to 8.0 and temperature range from 15℃ to 30℃.Under the optimal conditions(pH7.0,25 U/L laccase and 30℃),the transformation rate was positively correlated to reaction time and reached above 99.5% after approximately 24 h.Laccase activity was stable during the test time.In addition,the transformation rate obtained in tap water was nearly identical to that obtained in citrate-Na2HPO4 buffer.更多还原