饲料中脱氧雪腐镰刀菌烯醇的吸附脱毒研究

发布时间：2018-03-24 16:02

  本文选题：脱氧雪腐镰刀菌烯醇　切入点：吸附剂　出处：《华中农业大学》2016年硕士论文

【摘要】：脱氧雪腐镰刀菌烯醇(Deoxynivalenol,DON)是近年来对饲料及饲料原料污染率最高的霉菌毒素之一,它不仅对人畜健康造成危害,还给饲料业带来较大的经济损失。在饲料中添加吸附剂是现行方便、有效的脱毒方法,但传统的吸附剂对DON的吸附效率都很低,一般均小于30%。因此,寻找一种对DON具有高效吸附率的吸附剂迫在眉睫。本研究通过对众多吸附剂进行体外吸附试验,筛选出对DON吸附率高的吸附剂,研究其可能的吸附机制,并通过动物试验探究其在体内对DON的脱毒效果。吸附剂的筛选:取40mg吸附剂和400μL DON标准品(100 mg/L)于20mL缓冲体系中,恒温震荡孵育2h后,测定各吸附剂对DON的体外吸附率,结果表明,吸附剂d对DON的体外吸附率最高,为82.36%,各吸附剂对DON的体外吸附率大小依次为:吸附剂d吸附剂c吸附剂b葡聚糖、活化酵母细胞壁、凹凸土、腐植酸钠、吸附剂a白炭黑蛭石。其中,吸附剂a、吸附剂b、吸附剂c和吸附剂d为一类多孔固体的自选吸附剂,它们属于同一种物质但不同制作来源。因此,选择具有较高吸附率的自选吸附剂,尤其是吸附剂d进行后续研究。4种自选吸附剂粉碎后分别过20、40、60、80、100、120、140、160、180、200及200目以上标准筛,进行体外吸附试验探究粒径大小对吸附剂的体外吸附率的影响,结果表明随着吸附剂的粒径从20目减小到200目以上时,吸附剂对DON的体外吸附率逐渐增大。吸附剂添加量对其吸附效果影响的试验结果显示,吸附剂d的添加量从0.05%增加到0.6%时,其吸附率从53.15%逐渐升高到90.57%。通过解吸试验探究吸附剂d对DON的吸附稳定性,结果显示,吸附剂d解吸4.5h的累计解吸率为8.32%,说明吸附剂d对DON的体外吸附作用的稳定性较好。利用扫描电子显微镜(SEM)观察吸附剂表面的结构特征,结果显示吸附剂a表面光滑、孔隙不发达,其表面还散布有一些细屑;吸附剂b表面光滑,其上均匀分布着大孔;吸附剂c表面较粗糙,其上分布着一些中孔;吸附剂d的表面排布着均匀且规则的狭缝形孔隙。吸附剂d对DON的吸附机制:通过等温吸附试验及红外光谱法分析探究吸附剂d对DON可能的吸附机制。结果表明,吸附剂d对DON的体外吸附的回归曲线符合Langmuir方程,拟合回归方程为:c/Q=0.0003+0.0005c,R2=0.9112,最大吸附量Qm为2000mg/kg,其属于单分子层吸附。PH为7.0下,反应前后的吸附剂d均出现强烈的氢键或水中的O-H伸缩振动的吸收峰(波数为3414cm-1处)。PH变为2.0反应后,吸附剂d的IR图明显上移,且在1385cm-1和535cm-1处出现明显的吸收峰,这说明吸附剂d表面非水的O-H面内弯曲振动和Si-O-Al弯曲振动有明显的加强,其表面官能团发生了化学变化。因此吸附剂d对DON的吸附除了物理吸附还存在氢键吸附与化学吸附。动物试验:以小鼠为试验对象进行动物试验,探究体外吸附率高的吸附剂d在动物体内的实际脱毒效果。将72只3周龄昆明小鼠(雄性)随机分成6组,每组4个重复,每个重复3只小鼠,分别饲喂如下日粮:组Ⅰ-基础日粮;组Ⅱ-基础日粮+0.1%吸附剂d;组Ⅲ-基础日粮+0.2%吸附剂d;组Ⅳ-DON污染日粮;组Ⅴ-DON污染日粮+0.1%吸附剂d;组Ⅵ-DON污染日粮+0.2%吸附剂d。连续饲喂28 d,每天记录小鼠的采食量,每周记录其体增重。于试验第28d屠宰取样,并对小鼠的生长性能、脏器指数、全血细胞计数和血清生化指标进行检测分析。结果表明,组Ⅳ与组Ⅰ相比,脾脏指数显著升高(P0.05);淋巴细胞数(LYM)和淋巴细胞比率(LY%)显著降低(P0.05),中性粒细胞比率(NE%)显著升高(P0.05);血清谷丙转氨酶(ALT)和谷草转氨酶(AST)显著升高(P0.05)。而添加了吸附剂d的组Ⅴ与组Ⅵ小鼠的上述指标均恢复到对照组水平。这说明,添加吸附剂d对DON造成的小鼠肝功能和免疫功能的损伤有较好的缓解作用。综上所述,不同吸附剂对DON的体外吸附率差异较大;吸附剂的粒径大小与添加量对其吸附率有影响,其吸附率随着粒径的减小而增大,随着吸附剂添加量的增大而增大。筛选出了对DON体外吸附率较高的吸附剂d,其吸附率达82.36%,这可能与其表面特有的狭缝形孔隙及发达的孔隙结构有关;它对DON的吸附属于单分子层吸附,其既存在物理性吸附,还存在氢键吸附与化学性吸附。吸附剂d在动物体内对DON也有良好的脱毒效果,其对DON造成的小鼠毒性损伤有一定的缓解作用。
[Abstract]:Deoxynivalenol (Deoxynivalenol, DON) in recent years is one of the highest rates of mycotoxins in feeds and feed pollution, which not only cause harm to human and animal health, bring greater economic losses to the feed industry. Add in the feed the adsorbent is convenient, effective detoxification method, but the traditional adsorption the adsorption efficiency of DON is very low, generally less than 30%. so to find an efficient adsorbent for the rate of DON is imminent. In this study, through in vitro adsorption test on numerous adsorbents, screened DON adsorption rate, adsorption study the possible mechanism, and through animal test to explore the in vivo of DON detoxification effect. Selection of adsorbents: 40mg adsorbent and 400 L DON standard (100 mg/L) in the 20mL buffer system, temperature shock after 2H incubation in vitro, the adsorption of DON. The results show that the adsorption desorption rate, agent D on DON in vitro adsorption rate was the highest, was 82.36%, the adsorption rate of DON in vitro adsorbent size is as follows: D adsorbent adsorbent adsorbent C B dextran, activation of the yeast cell wall, attapulgite, sodium humate, adsorbent a silica in the vermiculite. A, adsorbent, adsorbent B, biosorbent C and D optional a kind of porous solid adsorbent, they belong to the same species but different production sources. Therefore, with optional adsorbent high adsorption rate, especially adsorption agent D for further study of.4 kind of optional adsorbent crushing after 20,40,60,80100120140160180200 and more than 200 mesh sieve effect standard, in vitro adsorption test to explore the particle size of the adsorbent in adsorption rate, the results showed that with the adsorbent particle size decreases from 20 mesh to 200 mesh above, the adsorption rate of DON adsorbent in vitro Increase the amount ofadsorbent. The experimental results show the influence on the adsorption effect, adsorption amount of agent D increased from 0.05% to 0.6%, the adsorption rate and adsorption stability, increased from 53.15% to 90.57%. on the adsorbent D DON through desorption experiment results showed that the cumulative desorption of adsorbent D desorption rate of 4.5H 8.32%, this shows that the stability of in vitro adsorption agent d to DON better. By using scanning electron microscopy (SEM) structures were observed on the surface of adsorbent, the results showed that the adsorption agent a smooth surface, pore developed, its surface is also interspersed with some fines; adsorbent B smooth surface, which are evenly distributed macroporous adsorbent; C rough surface, the distribution of some in the hole; the arrangement of agent D adsorbed on the surface of the slit shaped pore and uniform rules. The adsorption mechanism of the adsorption agent D on DON: by isothermal adsorption experiments and infrared spectroscopy analysis Study on adsorption mechanism of D adsorbent DON. The results showed that with the Langmuir equation of regression curve in vitro adsorption of D on DON, the regression equation is: c/Q=0.0003+0.0005c, R2=0.9112, Qm, the maximum adsorption capacity is 2000mg/kg, which belongs to the monolayer adsorption of.PH was 7, O-H stretching vibration absorption peak before and after adsorption reaction the agent D showed strong hydrogen bond or the water (wave number 3414cm-1) to 2.PH after the reaction, the adsorption was shifted to IR agent D, and appeared in the 1385cm-1 and 535cm-1 absorption peaks, indicating that the adsorbent D O-H table surface non water bend vibration and bending Si-O-Al the vibration significantly strengthened, chemical changes have occurred in the surface functional groups. So the adsorption on DON adsorbent D besides physical adsorption and chemical adsorption of hydrogen bonds also exist. Animal experiment: mice were used as experimental objects for animal experiment, inquiry body 澶栧惛闄勭巼楂樼殑鍚搁檮鍓俤鍦ㄥ姩鐗╀綋鍐呯殑瀹為檯鑴辨瘨鏁堟灉.灏，

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