固定化β-葡萄糖苷酶双相体系中水解大豆异黄酮

Hydrolysis of soybean isoflavone by immobilized β-glucosidase in a two phase system

采用共价交联的方法将β-葡萄糖苷酶固定到球形壳聚糖上,并对固定化酶的性质进行表征,得出固定化酶的最佳反应条件:pH=5,温度40℃。据此用乙酸乙酯和pH=5缓冲溶液的双相体系,在40℃条件下水解大豆异黄酮。与游离酶相比,固定化酶在此双相体系中起到了稳定酶的作用;与单相体系相比,双相体系中产物的产率显著提高,反应速率也更快,且能有效去除粗品大豆异黄酮的异味。对于30%左右级别的大豆异黄酮,水解的两个主要水解产物(大豆苷元和染料木素)的产率都能达到70%。

β-Glucosidase was immobilized on chitosan beads by cross-linking with glutaraldehyde, and was characterized. The optimum pH and temperature were 5 and 40℃, respectively. Soybean isoflavone was hydrolyzed in a two-phase system containing ethyl acetate and aqueous solution （pH = 5） . In this system, immobilized enzyme was more stable compared to free enzyme, and faster reaction rates and higher yields were obtained compared to the corresponding aqueous solution. The yields of the two main hydrolysis products （daidzein and genistein） of soybean isoflavone were both around 70%.