蛹虫草深层培养产纤溶酶条件的优化

Optimization of submerged culture conditions for the production of fibrinolytic enzyme with Cordyceps militaris

蛹虫草是名贵中药材之一，本课题组发现其液体发酵物中含有较强的纤溶活性物质，具有开发成溶栓药物∞潜力。以本实验室已优化的蛹虫草深层培养产纤溶酶的培养条件为基础，对蛹虫草深层培养产纤溶酶的条件进一步优化，并对其深层培养产纤溶酶过程从摇瓶条件到10L发酵罐进行比拟放大。实验结果表明：蛹虫草深层培养产纤溶酶的最适培养条件为蔗糖2％、豆饼5％，250mL三角瓶装液量为50mL，23℃培养5d，培养基初始pH为自然（6．0左右），接菌量为直径1cm菌片一片（每50mL）或深层培养3～5d的液体菌种0．5％（v／v）；10L发酵罐在搅拌转速和通风量为100r／min，600L／h的条件下纤溶酶活力达286．21U／mL（尿激酶单位），较摇瓶条件下的酶活力提高了3．2倍，纤溶酶对菌丝生物量的得率较摇瓶条件下提高了5．5倍。

Cordyceps rnilitaris is one of the medicinal mushrooms.A kind of enzyme with stronger fibrinolytic activity was found in the fermentation culture fluids of Cordyceps militaris, which had potential for treating thrombus.The fermentation conditions for the fibrinolytic enzyme production with Cordyceps mifitaris,which based on optimized condition in our laboratory,were further investigated.And the process of the fibrinolytic enzyme production was scaled-up from 250mL flask to 10L fermenter.The results showed that the best conditions for the fibrinolytic enzyme production were 250mL flask containing 50mL medium,which was composed of sucrose2% and bean cake 5%. The fermentation time was 5d under the temperature of 23℃. Keeping the initial pH of culture medium natural condition （about 6.0）was better for the fibrinolytic enzyme production.The better inoculums size was punching out lcm mycelia cultures into 50mL liquid fluids of 250mL flask.0.5% （v/v）liquid spawn of 3 -5d was also better.The fermentation of 10L fermenter under the conditions of agitation rate lOOr/min and aeration rate 600L/h got a better result for the fibrinolytic enzyme production. The area of the fibrinolytic enzyme active reached 286.21U/mL （urokinase） ,which was 3.2 times more than the results of flask.The yield was 5.5 times more than the results of flask.