单歧藻对烷基酚类化合物的生物降解性及QSBR研究

以单歧藻为主要微生物源,用二级反应动力学方程拟合8种烷基酚类化合物的生物降解动力学过程,得到它们在藻中的生物降解速率常数K.采用Mopac软件PM3法及文献资料计算了化合物的多种理化参数,应用SPSS统计软件做回归分析,对1gK进行了结构-生物降解性(QSBR)的研究.结果表明,疏水性参数lgK_ow,分子量M_w,一级价键连接指数1Xv,二级价键连接指数2Xv,生成热△H_f和分子偶极距μ能够较好地拟合烷基酚类化合物的生物降解速率,其中2Xv拟合效果最好.在此基础上,初步分析了烷基酚类化合物的生物降解机理,认为空间参数是决定其生物降解的主要因素,化合物的生成热和电性参数μ,E_homo的影响也不可忽视. 

Study on Biodegradability of Alkyl Phenols by Tolypothrix and QSBR

The biodegradation kinetic constants K of eight kinds of alkyl phenols by Tolypothrix were obtained by simulating the degradation process with the second-order kinetic equation. Many physicochemical parameters of eight alkyl phenols were calculated using PM3 method contained in the semi-empirical molecular orbital package (MOPAC) and referring to other literatures. With regression analysis by the computer software SPSS, the quantitative structure-biodegradability relationship (QSBR) study was made for biodegradation data lg K. The results indicate that lg K_OW, M_w,1Xν ,2Xν,ΔH_f and μ can well correlate with the rate of alkyl phenols biodegradation, in which 2Xν has the best simulating effect. On this basis, preliminary analysis of alkyl phenols biodegradation mechanism holds that steric parameters were dominant factors governing the biodegradability of alkyl phenols; but the effect of ΔH_f and electronic parameter μ on the final biodegradation products should not be ignored.