摘要
利用固定化β-葡萄糖苷酶把糖苷型异黄酮水解成苷元型异黄酮,可以提高大豆异黄酮的生理活性。用海藻酸钙包埋富含β-葡萄糖苷酶的黑曲霉孢子,可以方便有效地固定β-葡萄糖苷酶。研究考察了不同底物浓度,pH和温度对固定化β-葡萄糖苷酶酶解作用的影响,以及重复分批酶解条件下固定化酶的稳定性。当固定化酶珠体积占反应总体积的5%,糖苷型异黄酮浓度为1.2mg·mL-1,作用24h,酶解效果良好。其中,大豆苷比染料木苷易于被酶解。固定化酶适宜的pH范围为3～5,最适pH值为4.8。耐热性比固定化前有所增加,在70℃以下酶较稳定。重复分批酶解糖苷型异黄酮,连续7批的转化率均可保持在90%以上。该研究结果在大豆异黄酮的生物转化方面具有潜在的应用前景。
In order to improve the physiological activity of soybean isoflavone, the transformation of glucosides isoflavone to aglycone isoflavone was performed efficiently with the help of the immobilized β-glucosidase. The β-glucosidase was immobilized efficiently and easily by entrapping the β-glucosidase-rich Aspergillus niger spores into the calcium alginate. The effects of substrate concentration, pH value and temperature on the transformation reaction of immobilized β-glucosidase were studied. The stability of the immobilized β-glucosidase was also investigated via repeated batch hydrolysis. It was found that, when the glucosides isoflavone concentration is 1.2 mg·mL^-1, the volume of immobilized β-glucosidase beads used is 5% of the total reaction volume and the transformation time is 24 h, the effect of enzyme transformation is fairly good, and during which, the transformation of daidzin is much easier than that of genistin, Using the immobilized β-glucosidase, the suitable pH range for enzyme transformation was found as 3.0-5.0 with the optimal pH value of 4.8. The thermal stability of the β-glucosidase is improved via immobilization and the immobilized β-glucosidase is stable below 70℃. During repeated batch processes, the yield of transformation keeps higher than 90% during 7 batches. These research results are meaningful for the bio-transformation of glucoside isoflavone.
出处
《高校化学工程学报》
EI
CAS
CSCD
北大核心
2007年第2期304-309,共6页
Journal of Chemical Engineering of Chinese Universities
