黄曲霉毒素B_(1)降解菌的筛选鉴定及降解酶挖掘  

Screening and identification of aflatoxin B_(1) degrading bacteria and digging of degrading enzymes

作　　者：程思忠 谢岩黎[1,2] 孙淑敏 马卫宾[1,2] 李倩 杨玉辉 CHENG Si-Zhong;XIE Yan-Li;SUN Shu-Min;MA Wei-Bin;LI Qian;YANG Yu-Hui(College of Food Science and Technology,Henan University of Technology,Zhengzhou 450001,China;Oil and Food Safety Inspection and Control,Henan Provincial Key Laboratory of Grain,Zhengzhou 450001,China)

机构地区：[1]河南工业大学粮油食品学院,郑州450001 [2]河南省粮油食品安全检测与控制重点实验室,郑州450001

出　　处：《食品安全质量检测学报》2023年第4期1-7,共7页Journal of Food Safety and Quality

基　　金：河南省高校科技创新团队项目(20IRTSTHN023);郑州市重大科技创新专项(2020CXZX0077)。

摘　　要：目的 筛选、鉴定一株高效降解黄曲霉毒素B1(aflatoxin B_(1), AFB_(1))菌株,并对其降解特性和降解酶基因进行分析。方法 通过形态学观察、生理生化鉴定及同源性分析,对具有高效降解AFB_(1)能力的菌株进行鉴定。通过菌株发酵液、上清液、细胞悬液、胞内提取物对AFB1降解能力的不同确定降解活性部位,使用冷冻干燥方法探索其粗酶制剂对AFB1降解效果。结合全基因组分析进行降解酶基因的挖掘。结果 通过鉴定,菌株HNGD-B3为贝莱斯芽孢杆菌(Bacillus velezensis),菌株上清液对AFB1降解效果最好, 72 h降解率为88.24%±2.02%。上清液蛋白酶K处理后,对AFB_(1)降解效果大幅下降,热处理后上清液降解效果基本无变化,判断其降解活性成分为胞外酶。粗酶制剂可显著提高AFB_(1)降解效率,结合全基因组分析与Blastp比对筛选得到3条具有AFB_(1)降解潜力的候选基因序列。结论 菌株HNGD-B3对AFB_(1)具有良好降解效果,在生物降解真菌毒素中具有较大潜力。Objective To screen and identify a strain that can effectively degrade aflatoxin B_(1)(AFB_(1)), and analyze its degradation characteristics and degrading enzyme genes. Methods The strains with the ability to degrade AFB_(1)efficiently were identified by morphological observation, physiological and biochemical identification and homology analysis. The active site of AFB_(1)degradation was determined by the difference of AFB_(1)degradation ability of strain fermentation broth, supernatant, cell suspension and intracellular extract, and the effect of its crude enzyme preparation on AFB_(1)degradation was explored using freeze-drying method. Preliminary mining of degradation enzyme genes combined with whole genome analysis. Results The strain HNGD-B3 was identified and screened as Bacillus velezensis, and the 72 h supernatant of the strain had the best degradation effect on AFB_(1) with 88.24%±2.02%. The degradation rate of AFB_(1)by supernatant decreased significantly after treatment with proteinase K. The degradation effect of supernatant was basically unchanged after heat treatment, and the degradation active component was judged to be extracellular enzyme. The crude enzyme preparation could significantly improve the AFB_(1)degradation efficiency, and 3 candidate gene sequences with AFB_(1)degradation potential were obtained by combining genome-wide analysis with Blastp screening. Conclusion The strain HNGD-B3 has good degradation effect on AFB_(1)and has a greater potential in biodegradation of fungal toxins.

关 键 词：黄曲霉毒素B_(1) 生物降解 贝莱斯芽孢杆菌 粗酶制剂 全基因组 

分 类 号：X172[环境科学与工程—环境科学]