β-Proteobacteria菌降解甲基叔丁基醚的条件及中间代谢产物研究

采用可利用甲基叔丁基醚(methyl tert-butyl ether,MTBE)为唯一碳源和能源生长的1株β-Proteobacteria菌进行MTBE在密闭系统中的降解试验,确定了该菌降解MTBE的最适条件为:培养液初始pH值7.2,初始细胞浓度10⁷cells/mL,初始MTBE浓度为25 mg/L.考察了密封培养系统内培养液溶解氧对降解效果的影响,结果表明,在培养系统密闭前充入氧气可提高菌体对MTBE的降解速率.以气相色谱-质谱联用法检测到MTBE降解主要中间代谢产物是叔丁基醇、异丙醇、丙酮.在选择离子扫描模式下定量分析,得到降解过程中主要中间代谢产物的浓度变化曲线,据此推断MTBE的降解途径属于“丙酮途径”.

Conditions and intermediate metabolites of MTBE degradation by beta-Proteobacteria

One strain of beta-Proteobacteria that could utilize Methyl tert-Butyl Ether (MTBE) as sole carbon and energy resource was used for MTBE degradation in closed system. The culture conditions showed significant effect on the MTBE degradation and the optimum conditions were as following: original pH 7.2, initial cell concentration 10(7) cells/mL and initial MTBE concentration 25 mg/L. The effect of dissolved oxygen (DO) in medium of closed culture system on MTBE degradation was evaluated. It was found that supplication of oxygen into the closed system could significantly promote MTBE degradation. The analysis of intermediate metabolites of MTBE degradation by GC-MS showed that tert-butyl alcohol, isopropanol and acetone were the main intermediate metabolites. The concentration change of metabolites during the whole period of MTBE degradation suggested that the metabolic pathway of MTBE degradation was similar to the "acetone pathway".