泰乐菌素的微生物降解途径及其降解产物研究

研究了越南伯克霍尔德氏菌(Burkholderia vietnamiensis)对泰乐菌素的降解能力,并通过对降解产物的分析,推测了泰乐菌素的微生物降解途径.在自主筛选驯化分离到1株泰乐菌素高效降解菌B.vietnamiensis的基础上,采用高效液相色谱法测定其在不同条件下降解泰乐菌素的能力,并利用制备液相色谱分离纯化降解产物,质谱鉴定其结构.实验结果表明:B.vietnamiensis能高度耐受并快速降解泰乐菌素,用B.vietnamiensis处理初始浓度为50、100、200、300、400或500 mg·L-1的泰乐菌素培养基7 d,泰乐菌素的降解率均达到99%以上.B.vietnamiensis降解泰乐菌素的可能途径是:泰乐菌素A首先脱去碳霉糖转化为泰乐菌素B,然后分子中内酯键和醛基再经水解和还原生成2个新的降解产物.研究结果为泰乐菌素微生物降解机制的研究以及在此基础上降解酶的确定提供有价值的技术参考.

Study on microbial degradation pathway and products of tylosin residue in pharmaceutical waste

The objective of this work was to study the biodegradation capability of Burkholderia vietnamiensis to tylosin and propose the microbial degradation pathway of tylosin by investigating the degradation products. Based on a tylosin-degrading strain of B. vietnamiensis isolated from soil in our laboratory, the degradation of the tested strain to tylosin under different conditions was determined using high performance liquid chromatography (HPLC). The degradation products of tylosin were isolated and identified using preparative HPLC and mass spectrum. The results showed that B.vietnamiensis exhibited the high abilities to tolerate and degrade tylosin. Treatment with the tested strain degraded above 99% of tylosin in medium with an initial concentration of 50\,100\,200\,300\,400 or 500 mg·L^-1 after 7 d of incubation. The degradation pathway of B.vietnamiensis to tylosin might be that tylosin A was firstly desugared and transformed into tylosin B, and then lactone bond and aldehyde group in structure of tylosin B were hydrolyzed and reduced to generate two new degradation products. These results may provide a valuable reference for the further study on the microbial degradation mechanism of tylosin and the determination of tylosin-degrading enzyme.