木质素过氧化物酶降解四环素机理的研究  

Degradation Mechanism of Tetracycline by Lignin Peroxidase

作　　者：李星星[1,2] 鲍建国[1] 冷一非[1] 刘颖[1,2] 郭慧[1] 郑进[2] 

机构地区：[1]中国地质大学(武汉)环境学院,湖北武汉430074 [2]湖北理工学院环境科学与工程学院,湖北黄石435003

出　　处：《安全与环境工程》2016年第5期61-68,79,共8页Safety and Environmental Engineering

基　　金：国家自然科学基金项目(4137308)

摘　　要：为探究过氧化物酶对四环素类抗生素的降解机理,以白腐真菌Phanerochaete chrysosporium表达的木质素过氧化物酶(LiP)粗酶为研究对象,研究其产酶条件及其降解四环素(TC)的机理。结果表明:低浓度Mn2+可促进产酶,碳源、氮源限制是产酶的重要条件;降解反应进行10min后,H2O2消耗至阈值0.045mmol/L,LiP对TC的降解停止,其降解率达到82%;TC降解反应趋于平衡时,补加TC和H2O2后,LiP依然可以高效发挥作用,其二次降解率达到65%;LiP作用于不同初始浓度(10mg/L、25mg/L、50mg/L、100mg/L)TC,显示LiP对不同浓度TC均可有效降解,TC降解率分别为62%、80%、82%和90%;降解产物的抑菌性试验反映出降解产物较TC母体的抑菌性明显降低;LC/MS捕获到6种可能的降解产物E-TC、TP 461、E-TP 461、TP 477、TP 475和TP 445,并推测出LiP降解TC可能的降解途径。To study the mechanism of tetracycline antibiotics degradation by peroxidase,this paper chooses the crude enzyme of lignin peroxidase（LiP）from Phanerochaete chrysosporium as the research object,and explores the induction conditions of lignin peroxidase and degradation mechanism of tetracycline（TC）.The results indicate that the limitation of carbon,nitrogen and low concertation of Mn^2＋ are important factors for enzyme production.The degradation reaction of TC terminates when the concentration of H2O2 decreases to 0.045mmol/L,and the degradation rate reaches 82% within 10 min.LiP is still effective by adding TC and H2O2 when degradation reaction reaches balance,and the secondary degradation rate is 65%.Lignin peroxidase has a strong ability of TC degradation with different initial concentrations（10mg/L,25mg/L,50mg/L,100mg/L）,the degradation rate being 62%,80%,82%and 90%respectively.According to oxford cup tests,the transformation products of TC show lower antimicrobial potencies than the parent compound.There are six possible transformation products,namely,E-TC,TP461,E-TP 461,TP 477,TP 475 and TP 445 using LC/MS in the progress of TC degradation by LiP.Besides,the paper infers the potential degradation pathway of TC by LiP.

关 键 词：四环素(TC) 木质素过氧化物酶(LiP) 抑菌性 降解产物 降解机理 

分 类 号：X52[环境科学与工程—环境工程] X172