【作者】 刘媛婷；

【导师】 陈代文； 余冰；

【作者基本信息】 四川农业大学 ， 动物营养与饲料科学， 2011， 硕士

【摘要】 本研究考察五种霉菌毒素吸附剂等温吸附方程,探明吸附剂结合黄曲霉毒素B1(AFB1)的特性,筛选性能优异的两种吸附剂,研究其在体外和体内条件下对AFB1的吸附特性和使用效果。本研究共三个试验：试验一吸附剂结合AFB1特性的研究本试验旨在考察五种霉菌毒素吸附剂的吸附特性。试验中选用五种霉菌毒素吸附剂分别为,吸附剂A：主成分为酵母细胞壁提取物；吸附剂B：主成分为水合铝硅酸钠钙盐；吸附剂C：主成分是酵母细胞壁提取物与水合铝硅酸钠钙盐的复合物；吸附剂D：主成分是水合铝硅酸钠钙盐和活性炭；吸附剂E：主成分是酵母细胞壁提取物和活性炭。在体外条件下,通过等温吸附方程研究不同吸附剂对AFB1的吸附特性。结果表明：本试验条件下,五种吸附剂均对Freundlich等温式拟合程度较高,吸附方式主要是以化学吸附为主的多分子层吸附。在吸附量和亲和力上吸附剂B、D表现最优,被选出进行下面研究。试验二吸附剂结合AFB1能力的体外试验本试验分4个小实验,分别研究(1)不同pH值(2.0、5.0、6.0和8.0)环境下吸附剂对AFB1的吸附能力, (2)不同吸附时间(30、60、90、120、150、210min)时吸附剂对AFB1的吸附能力, (3)不同酸碱条件对吸附剂-AFB1复合体稳定性的影响, (4)两种吸附剂对不同程度霉变玉米中霉菌毒素吸附能力的影响。结果表明：(1)不同pH条件下,吸附剂D的吸附能力均显著高于吸附剂B(P<0.05)；(2)pH值为6.0时,吸附剂B在90min内对AFB1吸附率达到85.49%,吸附剂D为91.71%；(3)体外条件下,吸附剂D与AFB1形成的复合体解吸附率为15.05%,高于吸附剂B的6.99%,说明吸附剂D结合的吸附剂-AFB1稳定性低于吸附剂B；(4)在不同程度霉变玉米存在的情况下,两种吸附剂均能吸附饲料原料中的AFB1。说明,体外条件下,两种吸附剂对AFB1脱毒量大、作用力强、结合速度快,在90min内基本达到一个动态平衡状态,形成较为稳定的吸附剂-AFB1复合体,解吸附率低。吸附剂D脱毒量优于吸附剂B,吸附剂B的稳定性优于吸附剂D。试验三饲粮添加吸附剂对生长猪生产性能的影响本试验的目的是验证两种霉菌毒素吸附剂对生长猪饲料霉菌毒素的脱毒效果。选择20只健康60kg左右的生长猪,随机分为4个处理,每个处理5个重复,每个重复1只猪,饲养周期为15 d。4个处理分别为：对照组饲喂基础饲粮,基础饲粮为典型玉米豆粕型日粮；霉菌毒素组饲喂由自然霉变玉米100%替代正常玉米的饲粮,吸附剂B组和吸附剂D组饲粮分别在霉变玉米组饲粮中添加5000 mg/kg吸附剂B和5000mg/kg吸附剂D。统计日采食量(FI)、平均日增重(ADG)、料重比(F：G)。结果表明：与基础组相比较,霉菌毒素组生长猪FI、ADG有下降的趋势,F：G有增加的趋势(P>0.05)；两种添加吸附剂添加组对生长猪FI没有明显的影响(P>0.05),但有增加生长猪的ADG和降低F：G的趋势(P>0.05),且吸附剂D添加组的效果优于吸附剂B的添加组。综合上述试验,经体内体外试验和动物试验研究,主成分为水合铝硅酸钠钙盐的吸附剂D对AFB1的吸附作用效果最好。更多还原

【Abstract】 Three experiments were conducted to determine the adsorption characteristics and effects of mycotoxin adsorbents on aflatoxin B1 (AFB1) in Feed. The property of adsorption was evaluated, utilizing adsorption isotherm to selecte suitable adsorbents, and further tests were taken on the vitro sorption and vivo efficacy of AFB1Exp.1, The Study of Characterics of Absorbents on AFB1Vitro sorption of AFB1 on five adsorbents were characterized, two commercial adsorbents and three contrivable adsorbents were selected to sorb aflatoxin B1 (AFB1) as below:adsorbent A, main component is yeast cell extracts; adsorbent B, main component is HSCAS; adsorbent C, the compound of yeast cell extracts and HSCAS; adsorbent D, the compound of activated carbon and HSCAS; adsorbent E, the compound of activated carbon and yeast cell extracts. Adsorption isotherms were used in this test to describe the adsorption characteristics. Results showed that adsorbents fitted to the Freundlich isotherm, and suggested a multilayer of molecular of AFB1 adsorbed on adsorbents for their adsorption. For their greater adsorption quantity we chose adsorbent B and adsorbent D for further study.Exp.2, The Vitro Study of The Capacity of Absorbents on AFB1The adsorption capacity of the chose adsorbents was investigated by the follow condition:(1) AFB1 binding capacity by two adsorbents at pH 2.0,5.0,6.0,8.0, was compared, (2) AFB1 binding speed by two adsorbents in vitro condition was compared, (3)The stability of adsorbent-AFB1 complexes in vitro condition was conducted, (4) The binding capacity by two adsorbents to three degree of contaminated maize were compared. And primary results indicated that:(1) Adsorbent D showed the higher in vitro affinity for AFB1, than adsorbent B, (2) Adsorbent B bound 97.69% of the AFB1 in solution in 90min, and 96.03% adsorption rate by Adsorbent D, (3) Adsorbent B-AFB1 complex was much stronger than Adsorbent D-AFB1 the in vitro condition, (4) Both adsorbents showed high binding capacity for AFB1 in three extent contamination maize. It implied that:two adsorbents had a great detoxification capacity, strong adsorption adhesion, and short binding time, could form stable Adsorbent-AFB1 complex. Additionally, adsorbent D showed a greater capabilit than adsorbent B.Exp.3, Effect of Absorbents on Producing Performance of Growing Pig In vivo efficacy of two adsorbents as aflatoxin binders in finishing pig exposed to aflatoxin-contaminated feed was assessed. A total of 20 pigs were randomly allotted to four treatments (one pens per treatment of pig). As a result, feed intake (FI) and average daily gain (ADG) decreased (P>0.05) and feed gain ratio (F:G) increased (P>0.05) in the treatment fed aflatoxin-contaminated feed versus the control treatment. The data suggested that the two adsorbents tested alleviated the adverse effects on the growth preformence of finishing pigs caused by aflatoxin, while compared with adsorbent B, adsorbent D could alleviate the toxic effect of AFB1 more effectively.In conclusion, adsorbent D could bind AFB1 effectively both in vitro and in vivo. The adsorption is chemical interaction. These results indicated that adsorbent D could alleviate some of the toxic effect in swines. It might prove to be beneficicial in the management of aflatoxin-contaminated feedstuffs for swine.更多还原