PVA包埋产延胡索酸酶的黄色短杆菌的固定化研究

STUDIES ON IMMOBILIZATION OF B. FLAVUM POSSESSING FUMARASE BY ENTRAPMENT IN PVA

研究了用聚乙烯醇（ＰＶＡ）包埋黄色短杆菌的固定化成型技术。最佳的方法是ＰＶＡ３ｇ，海藻酸钠１ｇ，黄色短杆荫湿细胞１４ｇ，总体积为１００ｍｌ．制成直径为４ｍｍ的小珠。比较了ＰＶＡ包埋和卡拉胶包埋黄色短杆菌固定化细胞的延胡索酸酶活力和回收率，以及最适ｐＨ和最适温度。结果表明，二者没有显著区别。用０．３％胆酸处理固定化细胞能明显提高延胡索酸酶活力和抑制琥珀酸的产生。将ＰＶＡ包埋的固定化细胞装进一根２．５×１７ｃｍ的反应柱中，１Ｍ延胡索酸纳（ｐＨ７．２，温度３７℃）以每小时２０ｍＬ的速度过柱，每天可产Ｌ－苹果酸２０～２５ｇ，可连续稳定生产１００ｄ．

Shaping technique of immobilization was studied by using B.flavum cells entrapped in-to PVA. The most favouraboe preparation was PVA 3g,Na-alginate 1 g,B flavum cells 14 g(wet weight),total volume 100 mL.Bead-shaped particles with an average diameter of 4 mmwere made. The fumarase activity and yield of activity,optimal pH,temperature of immobilized B.flavum cells entrapped into PVA were compared with those entrapped into K-earrageenan. As aresult,both have no distinct difference.The immobilized cells treated by 0.3%cholic acid can ob-viously increase fumarase activity and suppress succinic acid formation.The immobilized cells inPVA was placed into a 2.5×17 cm column reactor. 1 M fumarate (pH7. 2 )was passed through thereactor at a flow rate 20 mL h￣(-1) at 37℃. Contitinuous and steady L─malic acid production at thelevel of 20～25 g per day was observed for a hundred -day period.