草甘膦曲霉生物降解的动力学研究

Studies on the kinetics of the biodegradation of glyphosate by Aspegillus.

曲霉B21可利用草甘膦为唯一碳源或磷源生长.在pH6.0、300mg/L草甘膦和7g/L葡萄糖组成的共基质底物系统中,草甘膦降解率可达97%.曲霉生长优先利用葡萄糖作为碳源和能源物质,生长进入减速期后开始快速降解草甘膦.应用分批补料培养方式,在底物浓度恒定条件下研究草甘膦底物抑制降解动力学模型,假设草甘膦和降解酶络合形成五元底物-酶复合物,得到的动力学模型和参数可以很好地模拟其生物降解过程.

Aspegillus B21 could grow utilizing glyphosate as the sole source of C or P. The degradation rate could reach 97% in pH=6 substrate and the system of common base matter composed of glyphosate 300 mg/L and glucose 7 g/L. Aspegillus gave priority to utilize glucose as carbon and energy sources for its growth, and glyphosate was degraded rapidly in the growth decelerated period. The kinetics model of degradation inhibited by glyphosate base matter was studied the condition of constant base matter concentration, applying the cultivation type of fed-batch, that could stimulate suppose glyphosate and degradation enzyme complex to form five unit base matter-enzyme complex, the kinetics mode and parameter could stimulate the biodegradation process of glyphosate very well.