【作者】 何万领；

【导师】 齐德生；

【作者基本信息】 华中农业大学 ， 动物营养与饲料科学， 2003， 硕士

【摘要】 本试验通过体外试验研究了膨润土对蛋氨酸、赖氨酸、维生素B₂、磷、氟、游离棉酚及黄曲霉毒素B₁（AFB₁）的吸附特性及对植酸与植酸酶活性的影响；通过急性动物试验研究了膨润土消除黄曲霉毒素B₁（AFB₁）的急性毒性作用；研究了利用膨润土制作新型防霉剂并考察了其防霉效果。 1 体外吸附试验 体外吸附试验表明膨润土对蛋氨酸和磷吸附很小，在pH2.0时最大吸附量分别为0mg／g和2mg／g，pH8.0时最大吸附量分别为6.4mg／g和41.2mg／g。解吸试验证明被吸附的蛋氨酸和磷用pH8.0水溶液可大部分被解吸。膨润土对赖氨酸最大吸附量在pH2.0，8.0下分别为250mg／g和125mg／g；酸性条件下的吸附量较碱性条件下高；在pH2.0，下吸附的赖氨酸用pH2.0、pH8.0水溶液解吸时，解吸率分别为97.97％和15.15％。膨润土对维生素B₂的吸附符合Nernst方程，即吸附量随维生素B₂浓度增加而增加，用pH8.0溶液解吸时，解吸率达100％。 膨润土对氟和游离棉酚有吸附作用，吸附量随氟和游离棉酚浓度增加而增加，pH2.0下最大吸附率分别为47.6％和66.5％，pH8.0下最大吸附率分别为78.9％和100％。被吸附的氟和游离棉酚用pH8.0溶液解吸时，只有少部分被解吸。膨润土对AFB₁的吸附符合Nernst方程，吸附量随AFB₁浓度增加而增加，pH2.0，8.0时，最大吸附率均为100％，用pH8.0水溶液解吸时，解吸率分别为28.6％和5.8％。竞争吸附试验表明，膨润土对AFB₁有选择吸附特性。 在水溶液中膨润土对植酸的吸附量随含量增加而增加，吸附率为66％。在植酸酶正常添加量时，膨润土对酶有活化作用，80℃湿热处理时膨润土对酶活有保护作用。 2．动物急性毒性试验 将3日龄麻鸭随机分成阳性对照组和试验组，阳性对照组按0.4mg／kg·bw和0.8mg／kg·bw的两个剂量水平经口灌服AFB₁，试验组灌服相同剂量的AFB₁和膨润土混合液。结果表明，未加膨润土的对照组动物死亡率分别为70％和100％，而膨润土组动物死亡率均为0％。可见，膨润土有对抗AFB₁对动物毒害的作用。 3．防霉试验 将有机酸及有机酸盐按一定比例与膨润土配合，制成不同种类的防霉剂。对水分14.0％的玉米粉只用有机酸配制的防霉剂，就有很好的抑菌效果，但普通有机酸防霉剂对水分16％的原料防霉效果较差，对水分18％和20％的原料无防霉效果。用山梨酸钾与有机酸复合配成的防霉剂的效果优于普通有机酸防霉剂。在水分17％时，添加0.5％和1％的山梨酸钾—有机酸复合防霉剂均有较好的防霉效果，但从经 膨润土对营养成分、有害物质吸附特性及防霖脱毒剂研究济角度考虑，以0.5%的添加比例为好。 膨润土对营养成分有吸附，但大部分可被解吸，对有毒物质的吸附量大且稳定，以其为载体制得的防霉剂有较好的防霉效果。因此，用膨润土作载体制作防霉脱毒剂有良好的应用前景。更多还原

【Abstract】 The adsorption properties of bentonite to Methionine , Lysine , riboflavin , phosphorus , fluorin ,phytic acid and free gossypol, and the effect of bentonite on the activity of phytase were studied. The acute toxicity experiment of AFB1 to duckling with and without bentonite was carried out. The effection of anti-mould agent with carrier of bentonite was evaluated too in this paper.1 The experiment of adsorption in vitroThe adsorption to methionine and phosphorus by bentonite was little at the conditions of pH 2.0 and pH8.0.The maximum adsorptions were only 0 mg/g, 2mg/g at pH2.0 and 6.4mg/g, 41.2mg/g at pH8.0 respectively, methionine and phosphorus sorbed on bentonite can be mostly desorpted with the solution of pH 8.0 .The maximum adsorption to lysine by bentonite was 250mg/g at pH2.0 and 125mg/g at pH8.0,and the quantity of adsorption in the acidic condition is higher than that in the alkaline condition, lysine could be desorpted from lysine-bentonite complex with solution pH8.0,the rate of desorption was 97.97% and 15.15% respectively. The adsorption to riboflavin by bentonite is accordance to the Nernst formula, and the quantity of adsorption increased with the concentration of riboflavin increasing. The desorption rate of riboflavin from riboflavin-bentontie complex was 100% with the solution pH 8.0.Fluorin and free gossypol can be adsorped by bentonite in solution pH2.0 and 8.0, the adsorption increased with the concentration of fluorin and free gossypol increasing, the maximum adsorption rate were 47.6%, 78.9% at pH2.0 and66.5%, 100% at pH8.0 respectivly ,and only a little of fluorin and free gossypol were desorpted with solution pH 8.0 . The adsorption to AFBi by bentonite is accordance to Nernst formula, the quantity of adsorption increased with the concentration of AFB1 increasing,the maximum rate of adsorption were both 100% at pH2.0 and pH8.0, the rate of desorption following by at pH8.0 was 28.6% and 5.8% respectively. The competition adsorption test indicated that bentonite can sorpted AFB1 selectivity.The adsorption to phytic acid by bentonite is accordance to Nemst formula, the quantity of adsorption increased with the concentration of phytic-acid increasing, the adsorption rate was 66%. Bentonite can prompt the activity of phytase in the normal level, and protect phytase from heat treatment at 80 for 30min in wet condition.2 The acute toxicity experimentAFB1 at 0.4mg/kg.bw and 0.8mg/kg.bw of avoirdupois were administrate to three days old duckling by p.o.,the death rate within 72h are 70% and 100% of positive control group, and death rate are both 0% of bentonite group, the results suggested thatthe bentonite can reduce the harmful effect of AFB1 to animal. 3 anti-mould experimentDifferent anti-mould agents were prepared with organic acids , their salt and bentonite. The mould is still growing on feed when the moisture of feed is 14% . The anti-mould agent only with organic acid can deter the growing of mould , but at the moisture of 16% the effect is less, and there was no effect as the moisture were 18%and 20% in feed . The anti-mould agent which supplied potassium sorbate additionally worked more effectively than that contained organic acid only. The result of the test of the anti-mould agent which supplied potassium sorbate additionally to deter mould growing showed that the agent added in feed as level of 0.5% was effective and more economical.The nutriments can be adsorbed by bentonite ,but they can be desorbed mostly ,and the adsorption of toxicants to bentonite was large and stability, so bentonite can be used as detoxify agent in feed and as carrier of anti-mould products.更多还原