表面活性剂增强联苯可生物利用性的研究

【作者】 付彦；

【导师】 修志龙； 贾凌云；

【作者基本信息】 大连理工大学 ， 生物化工， 2002， 硕士

【摘要】 为了考察表面活性剂对疏水性有机污染物生物降解的影响，本论文选择联苯作为模拟研究体系，筛选、驯化得到四株可利用联苯作为碳源生长的菌株；考察了联苯降解菌株对三种非离子表面活性剂OP-10、Tween-80、TritonX-100的生物可利用性；用高效液相色谱法测定了非离子表面活性剂对联苯的增溶曲线；较系统地研究了加入非离子表面活性剂对联苯生物降解速率的影响。实验结果显示：(1)通过四代驯化，细菌生长的延迟时间从250小时稳定到约20小时，真氧产碱杆菌DJ1(Alcaligenes eutrophus DJ1)和假单胞菌SM302(Pseudomonas SM302)均能较快地利用联苯生长并得到较高的生物量；(2)以上两株联苯降解菌株均能将非离子表面活性剂OP-10、Tween-80、Triton X-100作为第一生长基质加以利用，其中对OP-10、Tween-80的利用速率远高于对Triton X-100的利用速率；(3)当水相中的非离子表面活性剂浓度小于其CMC值时，对联苯的增溶效果不明显，增溶出现在高于CMC值时，联苯的溶解浓度与表面活性剂浓度成正比； (4)向培养体系添加浓度大于CMC值的表面活性剂对联苯的降解具有明显的促进作用，可以使联苯的平均比降解速率达到无表面活性剂时的3倍，而浓度低于CMC值的表面活性剂对联苯的降解影响不大。从而可以得出结论，表面活性剂的增溶作用对疏水性芳香化合物联苯的可生物利用性具有增强作用。更多还原

【Abstract】 In this study a microbial system for biphenyl biodegradation is set up in order to investigate the effects of surfactants on biodegradation of hydrophobic organic compounds. Four strains which can grow on biphenyl as the sole carbon and energy sources are selected out, in which Alcaligenes eutrophus DJ1 and Pseudomonas SMS02 are chosen as degradation strains. After studing the bioavailability of three nonionic surfactants (OP-10, Tween-80, and Triton X-100), they are added into the biodegradation system of biphenyl. The major experimental results are listed as follows: l)The lag time of Alcaligenes eutrophus DJ1 and Pseudomonas SM302 decrease from 255h and 216h to 24h and 3.5h, respectively, and the cells grow better one by one generation after four batchs of domestication. 2)Both strains can grow in presence of the nonionic surfactants of OP-10, Tween-80, Triton X-100 as the sole carbon source, among which OP-10 and Tween-80 are more suitable than Triton X-100 due to their high bioavailability. 3)When the concentrations of surfactants are below their critical micelle concentrations (CMCs), their effects of promoting the solubility of biphenyl are undetectable. If the concentrations of surfactants are beyond CMCs, they will promote the solubility of biphenyl in direct proportion. 4) The biodegradation rates of biphenyl increase to more than three times by adding surfactants above their CMCs into the microbial system, while little effects are observed at the cases of addition of surfactants below their CMCs. As a conclusion it could be drawn that the bioavailability of biphenyl can increase with the help of nonionic surfactants at high concentrations beyond their CMCs in the microbial system.更多还原