摘要
玉米赤霉烯酮(ZEN)主要是由镰刀菌产生的类雌激素真菌毒素,广泛污染玉米及其制品,严重威胁农产品安全和人民生命健康。ZEN的生物降解是保障农产品安全的重要手段。为探寻高效降解ZEN的微生物资源,本研究筛选鉴定了高效降解菌株,并对菌株降解条件、活性组分、应用潜能进行分析与探索。结果表明,本研究筛选出的菌株2X-7在48 h内能高效降解1 mg·L^(-1)ZEN,降解率达到90%。基于16S rDNA序列及全基因组中特异基因序列分析,最终鉴定其为贝莱斯芽孢杆菌(Bacillus velezensis)。该菌株对ZEN的最适降解条件为温度37℃、pH值7、碳源为蔗糖,在此条件下的ZEN降解率可达98%以上。该菌株的降解活性组分位于胞内,十二烷基硫酸钠(SDS)、高温处理均可使其失活,而经蛋白酶K处理后却表现出较高降解活性,推测水解形成的小分子肽可能具有降解能力。在37℃、pH值为7的条件下,污染1 mg·L^(-1)ZEN的玉米粉经该菌株处理,共孵育反应4 d,降解率可达43%。本研究可为ZEN的生物降解与应用提供理论依据和技术参考。
Zearalenone(ZEN)is an estrogenic mycotoxin primarily produced by Fusarium species.It widely contaminates maize and its products,posing a serious threat to agricultural safety and human health.The biodegradation of ZEN is an important strategy for ensuring agricultural safety.To explore high-efficiency microbial resources for ZEN degradation,this study screened and identified efficient degrading strains,and analyzed their degradation conditions,active components,and application potentials.The results indicated that a strain named 2X-7,screened in this study,can efficiently degrade ZEN at a concentration of 1 mg·L^(-1),achieving a degradation rate of 90%within 48 hours.Based on 16S rDNA sequence analysis and specific gene sequences from the whole genome,this strain was finally identified as Bacillus velezensis.The optimal conditions of ZEN degradation were determined to be at a temperature of 37℃,a pH of 7,and sucrose as the carbon source,under which the degradation rate of ZEN can reach over 98%.Furthermore,the active components responsible for the degradation were found to be intracellular.Both sodium dodecyl sulfate(SDS)treatment and high-temperature exposure could inactivate the degradation activity,while treatment with proteinase K retained a high level of degradation activity,suggesting that the hydrolysis products might consist of small peptides with degradation capability.When the strain was co-cultured with corn flour contaminated 1 mg·L^(-1) ZEN at 37℃and pH 7 for 4 days,the degradation rate reached 43%.This study provides theoretical basis and technical reference for the biodegradation of ZEN and its application.
作者
王刘庆
张晓
姜皓云
王蒙
WANG Liuqing;ZHANG Xiao;JIANG Haoyun;WANG Meng(Institute of Quality Standard and Testing Technology,Beijing Academy of Agriculture and Forestry Sciences,Beijing 100097)
出处
《核农学报》
北大核心
2025年第3期469-477,共9页
Journal of Nuclear Agricultural Sciences
基金
北京市农林科学院科技创新能力建设专项(KJCX20230217)。
作者简介
王刘庆,副研究员,主要从事农产品质量与安全研究。E-mail:wanglq@iqstt.cn;通讯作者:王蒙,研究员,主要从事农产品质量与安全研究。E-mail:wangm@iqstt.cn。
