摘要
菌株TR2（蜡状芽孢杆菌）的胞外粗酶液对氯氰菊酯无降解活性,而其胞内粗酶液对氯氰菊酯的降解效能高。胞内粗酶液对氯氰菊酯、氟氯氰菊酯和甲氰菊酯的降解效能较高,而对有机磷农药如乐果、敌敌畏、甲胺磷和毒死蜱等降解效能低。胞内粗酶液对氯氰菊酯反应适宜的pH为5.5～9.0,最适pH为8.0;粗酶液在pH6.0～9.0之间较稳定,在pH7.5最稳定,而在pH4.0～5.0和pH10.0则易于变性失活;粗酶液对氯氰菊酯反应适宜的温度在30～45℃之间,最适温度为35℃;粗酶液在40℃以下稳定性好,高于50℃则易于变性失活;粗酶液的米氏常数（Km）为692.39nmol/ml,最大反应速率（Vmax）为89.29nmol/min。
The extracellular crude enzyme of strain TR2, which was identified to be Bacillus cereus, was proved to have no degradation to cypermethrin, while its intracellular one had high degradation to cypermethrin. The intracellular crude enzyme was found to degrade cypermethrin, befenthrin and fenpropathrin efficiently, and also to be able to degrade methamidophos, dichlorvos and chlorpyrifos in low lever. The suitable pHs and temperatures for the crude enzyme were tested to be 5.5 - 9.0 and 30 - 45 ℃ respectively, and the optimal pH and temperature would be 8.0 and 35 ℃. The crude enzyme was also proved to be stable under the condition of pH 6.0 - 9.0 and below 40℃. The Michaelis - constant （ Km ） and maximum velocity （ Vmax ） were tested to be 692.39nmol/ml and 89.29 nmoL/min respectively.
出处
《青岛农业大学学报（自然科学版）》
2007年第3期185-188,192,共5页
Journal of Qingdao Agricultural University(Natural Science)
基金
国家自然科学基金资助项目(No.30370968)
关键词
蜡状芽孢杆菌
氯氰菊酯
降解酶
Bacillus cereus
Cypernethrin
degrading enzymes
