菊芋小孢根霉固态发酵纤溶酶的工艺优化

Solid-state Fermentation of Rhizopus microsporus var. tuberosus for Production of Fibrinolytic Enzyme

从酒曲中分离得到一株纤溶酶产生菌,经鉴定为菊芋小孢根霉.现对其固态发酵工艺的碳源、氮源、碳氮比、初始pH、含水量、无机盐、接种量、发酵时间、发酵温度和培养基厚度进行研究.结果表明,该菌株固态发酵工艺为:麸皮与豆粕比例2﹕1,初始pH,5.0,含水量(干基)1,mL/g,MgSO4,10,mmol/kg,(NH4)2,SO4200,mmol/kg,FeSO4,3,mmol/kg,接种量为6×106,g-1,培养基厚度为2,cm,29,℃恒温发酵72,h.最佳发酵条件下酶活力为684.39,U/g,是未优化时产酶量的8.2倍.通过对培养基的优化研究,使产酶量大幅提高,说明菊芋小孢根霉固态发酵纤溶酶具有工业潜力,也为工业化提供数据基础.

A strain producing fibrinolytic enzyme was isolated from starter. The strain was identified as Rhizopus micro- spores var. tuberosus. The effects of carbon source, nitrogen source, carbon nitrogen ratio, moisture of culture, initial pH, inorganic salts, inoculum size, fermentation time, temperature and medium thickness on the production of fibrinolytic en- zyme were investigated with solid-state fermentation. The results show that the appropriate conditions are as follows： carbon （bran） to nitrogen （bean pulp） ratio is 2 ： 1, initial pH 5.0, moisture of culture 1 mL/g dry basis, MgSO4 10 mmol/kg, （NH4） 2SO4 200 mmol/kg and FeSO4 3 mmol/kg. The optimized inoculum size, fermentation time, temperature and medium thickness are 6 ×10^6 spores/g solid substrate, 72 h, 29℃ and 2 cm, respectively. Under the optimized conditions the aver- age fibrinolytic enzyme activity reached 684.39 U/g. It is 8.2 times that of the original enzyme activity. All this indicates that solid-state fermentation of rhizopus microsporus var. tuberosus for production of fibrinolytic enzyme has industrial potential, and provides the basic data foundation for industrialization.