摘要
本试验旨在从霉变玉米和土壤中分离出一株可高效降解呕吐毒素(DON)的菌株。以氧化苯乙烯为唯一碳源进行初筛,通过富集和纯化培养分离出长势良好的目标菌株;以DON为唯一碳源进行复筛,通过酶联免疫吸附测定(ELISA)法检测各菌株对DON的降解率。采用显微镜油镜观察菌株形态特征、染色特性以及在固体培养基上的生长表现,并结合16S rRNA基因测序对菌株进行鉴定;同时,进一步探究其较适生长条件、胆盐和胃肠液耐受性及其降解机制。结果表明:1)从霉变玉米中分离出一株降解DON的菌,命名为BA-20,其DON降解率为(85.92±0.01)%;经鉴定,BA-20菌株为解淀粉芽孢杆菌(Bacillus amyloliquefaciens)。2)BA-20菌株较适生长温度和pH分别为37℃和7.0,同时对浓度为0.1%~0.3%的胆盐、pH=3的模拟胃液和pH=8的模拟肠液具有一定的耐受性。3)经活性物质定位和定性分析推测,BA-20菌株主要通过分泌一种蛋白酶发挥对DON的降解作用。综上所述,本试验从霉变玉米中分离到一株高效降解DON的解淀粉芽孢杆菌BA-20,为DON污染的生物防治提供了候选菌株,有助于保障饲料与食品安全。
This experiment was conducted to isolate a strain that can efficiently degrade deoxynivalenol(DON)from moldy corn and soil.The initial screening was conducted using styrene oxide as the sole carbon source,and the target strains with good growth were isolated through enrichment and purification culture.The re-screening was carried out using DON as the sole carbon source,and the degradation rate of DON by each strain was detected by enzyme-linked immunosorbent assay(ELISA).The morphological characteristics,staining properties and growth performance on solid medium were observed by using an oil immersion microscope,and the strains were identified by combining 16S rRNA gene sequencing.Furthermore,its more suitable growth conditions,bile salt and gastrointestinal fluid tolerance,as well as degradation mechanism were explored.The results showed as follows:1)a strain of DON degrading bacteria was isolated from moldy corn and named BA-20,with DON degradation rate of(85.92±0.01)%.It was identified that BA-20 strain was Bacillus amyloliquefaciens.2)The optimal growth temperature and pH of the isolated strain BA-20 were 37℃and 7.0,respectively.Meanwhile,it had certain tolerance to bile salts with concentrations of 0.1%to 0.3%,simulated gastric fluid with pH=3,and simulated intestinal fluid with pH=8.3)Based on the localization and qualitative analysis of active substances,it was speculated that the BA-20 strain mainly exerted the degradation effect on DON by secreting a protease.In conclusion,this study successfully isolates an efficient DON-degrading Bacillus amyloliquefaciens BA-20 from moldy corn,providing a candidate strain for the biological control of DON contamination and ensuring the safety of feed and food.
作者
杨冠华
邢娅丽
乔家运
李海花
李伟
YANG Guanhua;XING Yali;QIAO Jiayun;LI Haihua;LI Wei(Tianjin Key Laboratory of Conservation and Utilization of Animal Diversity,College of Life Sciences,Tianjin Normal University,Tianjin 300387,China;Tianjin Key Laboratory of Agricultural Animal Breeding and Healthy Husbandry,College of Animal Science and Veterinary Medicine,Tianjin Agricultural University,Tianjin 300384,China;Tianjin Zhongnongxing Technology Co.,Ltd.,Tianjin 301705,China)
出处
《动物营养学报》
北大核心
2026年第2期1559-1568,共10页
CHINESE JOURNAL OF ANIMAL NUTRITION
基金
天津市科技计划项目(24JRRCRC00070)。
