固定化桔青霉产生核酸酶P_1的研究

利用吸附固定在多孔聚酯载体上的桔青霉(Penicillium citrinum)菌丝细胞,在摇瓶中以分批发酵方式合成核酸酶P_1.试验结果表明:在固定化细胞产酶的条件下,培养液中葡萄糖和蛋白胨的最适浓度分别为10g/L和1g/L,摇瓶转速以180~200r/min为宜.固定化细胞经过48h的产酶周期,培养液中的核酸酶P_1活力可高达513.3U/ml,其产酶效率是游离菌丝的3.6倍,而葡萄糖和蛋白胨的用量仅为游离菌丝产酶的五分之一.在重复分批发酵试验中,固定化菌丝细胞形状稳定,连续28批(共56d)的产酶结果基本一致,每批的平均酶活力为507.4U/ml,在经济上和工艺上均显示了明显的优越性.

NUCLEASE P_1 PRODUCTION BY IMMOBILIZED PENICILLIUMCITR1NUM CELLS

Mycelia of Penicillium citrinum were adsorbed and immobilized efficiently within porous polyurethane. Nuclease P1 produced by the immobilized cells were studied in shaking flasks. The suitable glucose and peptone contents in medium were 10g/L and 1 g / L, respectively. And the shaking speed was 180-200 r / min. After 48h fermentation, the nuclease P1 activity reached 513.3 U / ml, the productivity was 3.6 times higher than that of the free cells. The production cost is obviously reduced. In repeated batch fermentation, the immobilized cells kept the capacity after 28 batches for 56 days with an average nuclease P1 activity of 507.4 U / ml.