摘要
脱氧雪腐镰刀菌烯醇(deoxynivalenol,DON)是一种广泛存在于自然界中的生物毒素污染物.本文利用富集培养的方法和微生物纯化分离技术,通过添加辅助因子吡咯喹啉醌(pyrroloquinoline quinone disodium salt,PQQ),从黄粉虫(Tenebrio molitor)幼虫的排泄物中分离得到1株可高效降解DON的菌株.该菌在30℃,pH 7.0的条件下,72 h内对浓度为50μg·mL^(−1)的DON降解率高达100%,降解产物为3-keto-DON.通过形态学鉴定和基于16S rDNA序列构建的系统发育树分析,该菌的分类地位归属为德沃斯氏菌属(Devosia sp.).对该菌在不同温度、pH、PQQ浓度和不同脱毒方式下进行降解性质表征,发现该菌静息细胞在好氧或者静置,30℃、pH 7.0—9.0、PQQ浓度为0.01—10μmol·L^(−1)的条件下具有良好的DON降解能力.为了确定该菌降解的活性物质,取未处理、加热处理和SDS处理的菌悬液和菌体细胞裂解上清液分别对DON进行降解,结果显示该菌利用自身产生的酶对DON进行降解.
Deoxynivalenol(DON)is a biotoxic pollutant prevalent throughout nature.In the present study,a DON-degrading bacterial strain SD9-2 was isolated from the excreta of Tenebrio molitor larvae with the addition of the cofactor Pyrroloquinoline Quinone Disodium(PQQ)by enrichment culture method and microbial purification isolation technique.The strain SD9-2 could efficiently remove DON(50μg·mL^(−1))at a degradation rate of 100%within 72 h at 30℃.The strain was designated a member of the genus Devosia sp.by morphological identification and phylogenetic tree construction based on 16S rDNA sequences analysis.The bio-degradation product of DON was proved to be 3-keto-DON.The DON-degradation abilities of SD9-2 were characterized at different temperatures,pH,PQQ concentrations and detoxification methods.The optimized bio-degration conditions of the strain were at 30℃and pH 7.0-9.0,with 0.01-10μmol·L^(−1) PQQ under aerobic and static conditions.In addition,the cell suspension and cell lysate supernatant could completely degrade DON,and the degradation activity disappeared after heat treatment and sodium dodecyl sulfate(SDS)treatment.The results indicated that biocatalysis of the enzyme was responsible for the conversion from DON to 3-keto-DON.
作者
赵冬蕾
汪洋
张春娥
刘彤彤
李慧敏
黄凯
郭宝元
ZHAO Donglei;WANG Yang;ZHANG Chun’e;LIU Tongtong;LI Huimin;HUANG Kai;GUO Baoyuan(School of Health Science and Engineering,University of Shanghai for Science and Technology,Shanghai,200093,China;Academy of National Food and Strategic Reserves Administration,Beijing,100037,China;Ningxia Hui Autonomous Region Grain and Oil Product Quality Inspection Center,Yinchuan,750001,China)
出处
《环境化学》
CAS
CSCD
北大核心
2024年第8期2845-2853,共9页
Environmental Chemistry
基金
宁夏回族自治区重点研发计划(2022BBF03031)
国家自然科学基金(31972605)资助.
