真菌毒素生物脱毒机理的研究进展

真菌毒素是多种真菌的次生代谢产物,广泛存在于谷物及牲畜饲料之中,对人类及动物造成危害。去除真菌毒素的方法包括物理、化学和生物降解的方法。从目前的研究进展来看,生物降解真菌毒素主要通过微生物细胞壁吸附、酶降解和酵母发酵。     

霉变饲料中添加复方霉菌毒素吸附剂对肉鸡人工感染发生的影响

本试验旨在研究霉变饲料和／或添加复方霉菌毒素吸附剂对肉鸡人工感染发生的影响。选取140羽1日龄健康的AA肉鸡随机分成7个组．每组4个重复。第1组为空白对照组,饲喂基础日粮;第2组饲喂霉变饲料;第3～7组以混合感染病鸡病变组织匀浆饮水制作人工感染疾病模型;第3～7组分别饲喂基础日粮、霉变饲料、霉变饲料＋复方霉菌毒素吸附剂、霉变饲料＋复方霉菌毒素吸附剂＋抗氧化剂、霉变饲料＋复方霉菌毒素吸附剂＋抗氧化剂＋中药增免剂。试验期35d。结果发现,肉鸡摄入霉变饲料与摄入正常饲料相比,提高肉鸡料重比和死淘率,显著降低肉鸡增重、胸腺指数、法氏囊指数,显著降低血清IBDV、H9N1v和NDV抗体水平（P〈0．05）。给人工感染肉鸡饲喂霉变饲料与饲喂正常饲料相比．显著提高料重比和死淘率,显著降低肉鸡增重、胸腺指数和脾脏指数,显著降低血清IFN-1、IL-2、IL-4和IL-12含量以及LTR,显著降低血清IBDV、H9N1V和NDV抗体水平（P〈0．05）。霉变饲料中添加复方霉菌毒素吸附剂能显著提高混合感染肉鸡增重,并降低料重比和死淘率（P〈0．05）,显著提高胸腺指数、法氏囊指数（P〈0．05）,显著提高血清IBDV、H9N1V和NDV抗体水平（P〈0．05）。可见,霉变饲料可导致肉鸡免疫功能抑制,加重肉鸡混合感染病情;复方霉菌毒素吸附剂能有效缓解霉变饲料对人工感染肉鸡生产性能、免疫功能和病情的不利影响,抗氧化剂和免疫功能增强剂可减轻霉变饲料的毒性作用。     

霉菌毒素的危害及其吸附剂的研究进展

每年霉菌毒素给养殖业造成严重的经济损失,研究霉菌毒素的危害和正确选择霉菌毒素吸附剂进而减少霉菌毒素造成的危害已刻不容缓。本文就常见霉菌毒素的危害及其吸附剂作一综述。     

Segregation for aggressiveness and deoxynivalenol production of a population of <Emphasis Type="Italic">Gibberella zeae</Emphasis> causing head blight of wheat

Gibberella zeae is a pathogen of wheat and other small-grain cereals, causing yield losses and reducing grain quality by producing the trichothecene deoxynivalenol (DON) which is harmful to animals and humans. One hundred and fifty three progeny from a cross between two European DON-producing isolates of G. zeaewere analyzed for aggressiveness and DON production in three environments (location–year combinations) in Germany. Aggressiveness, measured as head blight rating and relative plot yield, and DON production showed continuous distribution for each environment and across environments. There was significant (P=0.01) genotypic variation for all three traits. Transgressive segregants occurred for all three traits. Both repeatability estimates within an environment and heritability estimates on an entry-mean basis for head blight rating and DON production were medium to high (0.5–0.7). Progeny–environment interaction accounted for about 29% of the total variance for the two aggressiveness traits and 19% for DON production. The large genetic variation derived from a cross between two rather similar European parents indicates a potential for increasing fungal aggressiveness in theG. zeae population.     

谷物真菌毒素溯源系统初探

主要探讨了谷物制品中真菌毒素类溯源系统构建的基本原理以及模式,包括构建分级溯源点的方式,设计各溯源点的主要功能以及具体详尽的实现流程。在部分关键环节,将胶体金免疫层析检测技术运用于其中,建立以快速检测为技术核心的食品溯源系统,对于控制食品质量安全、促进食品国际贸易具有重大的现实意义。     

镰刀菌毒素及其分子生物学研究进展

综述了近年来国内外关于小麦赤霉菌主要致病菌种禾谷镰刀菌毒素的形成与致病力的关系、毒素生物检测及免疫化学检测方法、脱毒技术及毒素代谢途径的分子生物学研究的一些进展。     

Piriformospora indica reduces fusarium head blight disease severity and mycotoxin DON contamination in wheat under UK weather conditions

Piriformospora indica (Sebacinaceae) is a cultivable root endophytic fungus. It colonizes the roots of a wide range of host plants. In many settings colonization promotes host growth, increases yield and protects the host from fungal diseases. Evaluation was made of the effect of P. indica on fusarium head blight (FHB) disease of winter (cv. Battalion) and spring (cv. Paragon, Mulika, Zircon, Granary, KWS Willow and KWS Kilburn) wheat and consequent contamination by the mycotoxin deoxynivalenol (DON) under UK weather conditions. Interactions of P. indica with an arbuscular mycorrhizal fungus (Funneliformis mosseae), fungicide application (Aviator Xpro) and low and high fertilizer levels were considered. Piriformospora indica application reduced FHB disease severity and incidence by 70%. It decreased mycotoxin DON concentration of winter and spring wheat samples by 70 and 80%, respectively. Piriformospora indica also increased aboveground biomass, 1000‐grain weight and total grain weight. Piriformospora indica reduced disease severity and increased yield in both high and low fertilizer levels. The effect of P. indica was compatible with F. mosseae and foliar fungicide application. Piriformospora indica did not have any effects on plant tissue nutrients. These results suggest that P. indica might be useful in biological control of Fusarium diseases of wheat.     

饲料中添加壳寡糖和/或霉菌毒素吸附剂对凡纳滨对虾生长性能、非特异性免疫力及抗病力的影响

本试验旨在研究在饲料中单独或联合添加壳寡糖(COS)和霉菌毒素吸附剂(MA)对凡纳滨对虾(Litopenaeus vannamei)生长性能、非特异性免疫力及抗病力的影响。首先配制基础饲料(C0组,作为对照组),然后在基础饲料中分别添加100 mg/kg COS(C0.1组)、250 mg/kg COS(C0.25组)、2 500 mg/kg M A(M 2.5组)、100 mg/kg COS+2 500 mg/kg M A(C0.1+M 2.5组)、250 mg/kg COS+2 500 mg/kg MA(C0.25+M2.5组),共制成6种等氮等脂的试验饲料,投喂初重为(0.23±0.02)g的凡纳滨对虾8周。每组设3个重复,每个重复放养40尾对虾。结果表明:1)C0.1+M2.5组的特定生长率、增重率显著高于M2.5组(P0.05),C0.1+M2.5组的饲料系数最优,显著低于其他各组(P0.05),C0.1+M2.5组的蛋白质效率最高并显著高于除C0.25+M 2.5组外的其他各组(P0.05);C0.1+M 2.5组的虾体粗蛋白质含量较C0.1组显著升高(P0.05),虾体粗脂肪含量较C0.1组显著降低(P0.05)。2)C0.1+M 2.5、C0.25+M 2.5组血清中碱性磷酸酶(AKP)活性均显著低于C0.1和C0.25组(P0.05),C0.1+M2.5组血清中超氧化物歧化酶(SOD)、酚氧化酶(PO)活性均显著高于M2.5和C0.1组(P0.05),C0.1+M2.5组血清中丙二醛(MDA)含量显著低于C0.1组(P0.05);C0.1+M2.5组肝胰腺中MDA含量显著低于C0.1组(P0.05),C0.25+M 2.5组肝胰腺中AKP、PO、SOD、溶菌酶(LZM)活性比C0.1+M 2.5组均有降低,相反肝胰腺中MDA含量则有所升高。3)以哈维氏弧菌攻毒7 d后,C0.1+M2.5及C0.25+M 2.5组的累积死亡率均显著低于C0和M 2.5组(P0.05)。由结果可知:本试验条件下,饲料中添加一定量的COS和/或MA均能促进凡纳滨对虾的生长,联合添加COS与MA的促生长、提高免疫力和抗病力的效果优于单独添加COS和MA,综合来看,以100 mg/kg COS和2 500 mg/kg M A联合添加时作用效果较佳。     

奶牛养殖中霉菌毒素的危害和脱毒技术

霉菌毒素是真菌产生的有毒的二级代谢产物,经常在奶牛饲料及其原料中发现。最常见的霉菌毒素是黄曲霉毒素（AF）、伏马菌素（FB）、玉米赤霉烯酮（ZEN）、脱氧雪腐镰刀菌烯醇（DON）、T-2毒素和赭曲霉毒素A（OTA）。当饲料中霉菌毒素的浓度超过一定水平时,会导致奶牛发生免疫抑制、肝肾毒性、繁殖障碍等诸多健康问题。奶牛饲料原料在生长、收获、加工和储藏过程中不可避免受到霉菌毒素的污染,应用脱毒方法是预防霉菌毒素危害奶牛健康的关键控制点。物理、化学和生物脱毒是实现霉菌毒素脱毒的常见技术措施。其中,物理吸附和生物降解脱毒具有安全、绿色、去除率高、不破坏饲料营养物质等诸多优势,是国内外研究的重点和方向。本文主要介绍了奶牛饲料中常见霉菌毒素的生物特性、致病机理及其对奶牛的危害和物理、化学、生物脱毒方法,为防控霉菌毒素污染,实现健康养殖提供参考。