摘要
分离到 1株高产果胶酶菌株 ,经形态、生理以及生化指标鉴定 ,确认为枯草杆菌 (Bacillussubtilis)并命名为枯草杆菌 1 8。发酵液用 90 %硫酸铵沉淀 ,透析后的粗酶经CM - 5 2柱层析 ,收集酶峰 ,再过ShephadexG - 1 0 0得部分纯化酶。该酶最适pH9.0 ,在 pH9～ 1 1稳定 ,最适反应温度 6 0℃ ,5 0℃加热 5 0min保存 6 0 %酶活 ,6 0℃加热 5 0min酶活则保存 1 0 %。酶的等电点 ( pI) 4.0 ,分子量 31 0 0 0。该酶对苎麻脱胶有较好的特异性。
A pectic enzyme overproductive strain was selected, which was identified as B.subtilis by morphological, physiological and biochemical studies.Crude enzyme was obtained from culture supernatant and then purified by 90% ammonia sulfate fractionation,cellulose CM-52 chromatography and Sephadex G?100. The purified pectic enzyme preparation was identified to be homogeneous by SDS electrophoresis .From the results of SDS-PAGE,the molecular weight of pectic enzyme was 31000 D.The optimal pH and temperature for the enzyme reaction was 9.0 and 60℃.The enzyme was stable at pH 9-11.After 10 min at 50℃,the enzyme activity was 60%;and at 60℃ for 50 min,the enzyme activity was only 10% of the original.The enzyme had better specificity for ramie retting.
出处
《工业微生物》
CAS
CSCD
2000年第1期25-27,共3页
Industrial Microbiology
