1株木质素降解菌的筛选、鉴定及固态发酵产酶优化  

Screening and identification of a lignin-degrading strain and optimization of its enzyme production by solid-state fermentation

作　　者：寇慧 黄长浩 严骋 邹伟 KOU Hui;HUANG Chang-hao;YAN Cheng;ZOU Wei

机构地区：[1]四川轻化工大学生物工程学院,四川宜宾644005

出　　处：《饲料研究》2023年第9期85-92,共8页Feed Research

基　　金：四川轻化工大学研究生创新基金项目(项目编号:y2021048);自贡市重点科技计划项目(项目编号:2019YYJC27)。

摘　　要：研究旨在通过筛选高效木质素降解菌,优化其产酶过程,提高木质素降解率和秸秆降解率。试验以木质素为唯一碳源初筛,通过苯胺蓝-PDA培养基、愈创木酚-PDA培养基、碱性木质素降解率复筛,最终以在发酵培养基中木质素过氧化酶、锰过氧化酶、漆酶酶活为指标进行筛选,通过单因素和正交法进行固态发酵产酶优化。结果显示,试验筛选出1株高木质素降解率的菌株M20,经形态和内转录间隔区(ITS)序列分析初步确定为Aspergillus oryzae。在以油菜秸秆为基质的发酵培养基上进行产酶优化,秸秆与麸皮比例、发酵时间、氮源添加量为产木质素酶显著影响因子;正交试验确定油菜秸秆固体培养基最优条件为秸秆与麸皮比为2∶1、(NH4)2SO4添加量为3%、发酵4 d。在此条件下,优化后木质素过氧化酶酶活为1796.74 U/g,锰过氧化酶酶活为146.78 U/g,漆酶3.979 U/g,比未优化的3种木质素降解酶分别提高了60.28%、45.14%、27.00%。研究表明,菌株M20在油菜秸秆生物降解方面具有较大的应用前景,可在一定程度上为秸秆资源化利用提供了新的微生物资源。The study was to screen efficient lignin degrading bacteria,optimize their enzyme production process,to improve the lignin degradation rate and straw degradation rate.The experiment used lignin as the sole carbon source for initial screening.Aniline blue PDA medium,guaiacol PDA medium and alkaline lignin degradation rate were re-screened.Lignin peroxidase,manganese peroxidase,and laccase activity in fermentation medium were selected as indicators at last,and solid-state fermentation enzyme production was optimized through single factor and orthogonal methods.The results showed that a strain M20 with high lignin degradation rate was screened and preliminarily identified as Aspergillus oryzae through morphological and ITS sequence analysis.Optimization of enzyme production was carried out on a fermentation medium based on rapeseed straw.The ratio of straw to bran,fermentation time and nitrogen source addition were significant influencing factors for lignin enzyme production.The optimal conditions for the solid culture medium of rapeseed straw were determined through orthogonal experiments as follows:the ratio of straw to bran of 2∶1,the addition of(NH4)2SO4 of 3%,the fermentation lasted for 4 d.Under these conditions,the optimized lignin peroxidase enzyme activity was 1796.74 U/g,manganese peroxidase enzyme activity was 146.78 U/g and laccase activity was 3.979 U/g,which increased by 60.28%,45.14%and 27.00%compared with the three lignin degrading enzymes that were not optimized,respectively.The study indicates that the strain M20 has great application prospects in biodegradation of rapeseed straw,which can provide new microbial resources for straw resource utilization to a certain extent.

关 键 词：油菜秸秆 木质素 生物降解 木质素酶 固态发酵 

分 类 号：S816.7[农业科学—饲料科学]