【摘要】 用乙酸纤维将ＧＬ－７－ＡＣＡ酰化酶基因工程菌大肠埃希氏菌Ａ５６／ｐＭＲＣＵ－３３４菌株固定化，酶反应的最适温度为５０℃，最适ｐＨ为８．０，与游离细胞一致；固定化细胞对温度和ｐＨ的稳定性比游离细胞提高。用薄板层析分析固定化细胞裂解ＧＬ－７－ＡＣＡ反应液中产物７－ＡＣＡ的含量以及ＧＬ－７－ＡＣＡ的残存量，在ｐＨ８．０．３７℃时ＧＬ－７－ＡＣＡ的转化率达９０％，产生７－ＡＣＡ的能力为１２．３４ｍｇ／（ｇ固定化细胞·ｈ）。使用２０批之后，ＧＬ－７－ＡＣＡ的转化率仍达６６％。更多还原

【Abstract】 Escherichia coli A56/pMR CU 334 is a recombinant strain with activity of GL 7 ACA acylase. The cells were immobilized by entrapping into acetate cellulose. The optimum temperature and optimum pH of GL 7 ACA acylase of the immobilized cells were 50℃ and pH8.0, it was the same as that of the free cells. The stability of the immobilized cells to variation of pH and temperature was higher than that of the free cells. The 7 ACA and GL 7 ACA concentration in reaction mixture was determined by thin layer chromatography. The conversion of GL 7 ACA by the immobilized cells was 90% at pH 8.0, 37℃. The yield of 7 ACA from GL 7 ACA by the immobilized cells was 12.34 mg/(g immobilized cells·h). The immobilized cells showed very good operational stability. After 20 batches in continuous cycles, the conversion rate of GL 7 ACA was 66%.更多还原