微嗜酸寡养单胞菌中的漆酶对黄曲霉毒素B1降解脱毒的生物活性

[目的]探究微嗜酸寡养单胞菌中的漆酶对AFB1的降解活性,并确定漆酶在菌株CW117降解代谢AFB1过程中的贡献.[方法]从微嗜酸寡养单胞菌基因组中,共筛选到两个漆酶基因lc1和lc2,并用大肠杆菌BL21外源表达蛋白rLC1和rLC2,在体外检测其对AFB1的降解活性.同时参考前人报道,研究了氧化性辅剂对漆酶AFB1...

Characterization of the aflatoxin B1 degradation role of laccases in Stenotrophomonas acidaminiphila

[Objective]Characterization of the aflatoxin B1(AFB1)degradation roles of the laccases screened from Stenotrophomonas acidaminiphila CW117.[Methods]Two laccase genes lc1 and lc2 from strain CW117 genome were screened,and their AFB1 degrading activity was examined in vitro by heterologous expressed proteins of rLC1 and rLC2 in E.coli BL21.On the basis of in vitro test,two laccase-deficient strains CW117Δlc1and CW117Δlc1-lc2 were constructed by homologous recombination method by using suicide plasmid pK18mobsacB,and the laccases(lc1 and lc2)AFB1 degradation role on strain CW117 was validation in vivo.[Results]Laccase rLC1 showed the AFB1 degradation activity in vitro,but rLC2 did not show degradation activity.Degradation activity of rLC1 was improved by redox mediators of 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid),acetosyringone or syringaldehyde.The degrading activity of mutants CW117Δlc1 and CW117Δlc1-lc2 showed similar degradation activity to the wild-type strain CW117 in most evaluation time-points.[Conclusion]Laccase LC1 from S.acidaminiphila showed AFB1 degradation activity,and the degradation activity could be enhanced by redox mediators as previous study.However,the laccases’contribution to AFB1 degradation in strain CW117 was minimal,and other degradation pathways existed in the strain.