嗜热链霉菌变株M1033-9葡萄糖异构酶的研究——Ⅱ.酶的性能与工业应用

STUDIES ON D-GLUCOSE ISOMERASE OF THERMOPHILIC STREPTOMYCES MUTANT STRAIN M1033-9——Ⅱ.ENZYME PROPERTIES AND INDUSTRIAL APPLICATION

嗜热链霉菌变株(Streptomyces diastaticus No.7 mutant strain)M1033-9菌的胞外葡萄糖异构酶作用最适温度为80—85℃,最适 pH 为8—9,pH 大于7.8时有较强的热稳定性,Co^(2+)和 Mg^(2+)对酶有激活作用,Co^(2+)对酶的热稳定性有保护作用。5000L 发酵罐经板框过滤的清发酵液含胞外酶885u/ml,占总酶活94%,可直接作酶源吸附于大孔阴离子交换树脂上制成固定化葡萄糖异构酶(酶活13000u/g(干))工艺简便。年产2000吨42型果葡糖浆规模下每公斤干固定化酶可生产果葡糖浆4.59吨。M1033-9是产胞外葡萄糖异构酶的优良菌种。

The optimum temperature of the extracellular D-glucose isomerase(GI)of mutantstrain M1033-9 was 80—85℃,optimum pH was 8—9.In condition of pH7.8,the enzymehad better thermostability,both Co^(2+) and Mg^(2+) enhanced activity of enzyme,Co^(2+) had aprotection effect on enzyme thermostability.The clear broth of 5000L fermentor,which wasfilterated by plate and frame filter,included 885u/ml of extracellular GI which took up94% of total activity of GI.The clear broth was able to produce the immobilized GI(13000u/gdry)which was adsorpted in the large pore anion exchange resin.This techniquewas simplized.1 kg of immobilized GI(dry)could isomerizate glucose syrup(8000Ωcm)toproduce 4.59 tons of fructose glucose syrup.