曲霉AH625产酶条件与酶液降解制备壳寡糖

Cultural Condition and Preparation of Chitooligosaccharides by Enzyme from Aspergrillus Sp AH625

从特定土壤中分离出一株能分泌胞外甲壳酶的高产菌株曲霉AH62 5 ,在以甲壳素为唯一碳、氮源的平板上长势良好 ,该菌株在生长培养基中振荡培养 72h ,再转移至诱导培养基中培养 2 4h ,酶活力可达 0 .51 2u/mL。研究表明 ,该菌株的最佳产酶条件是 :温度2 8℃ ,起始 pH4 .8,诱导底物为 1 .5 %的水溶性壳聚糖 ,0 .1 %的表面活性剂Tween80能使产酶量提高 2～ 3倍。用粗酶液在 50℃ ,pH5 .0条件下降解壳聚糖 ,得Mw 为 1 1 2 7,Mw/Mn 为 1 .53的壳寡糖。

Aspergrillus sp AH625 secreting extracellular chitinase was isolated from special soils samples, well growing in a medium containing chitin as sole carbon and nitrogen source. It was first grown in a growth medium for 72h and then transferred to an inductive medium for 24h. The peak of chitinase activities was 0.512u/Ml, and optimal conditions for chitinase producing were 28℃, initial pH 4.8 and 1.5% soluble chitosan as inductive medium. 0.1% Tween80 can activate chitinase activities.