纳豆激酶产生菌的固体发酵参数优化

对影响纳豆激酶产生菌固体发酵时产酶影响因子如碳源/氮源、含水量、温度、pH和培养时间等进行了优化.实验结果表明,菌株1适宜的固体发酵产酶培养基豆粕:麸皮比为3∶1;菌株2适宜的固体发酵产酶培养基豆粕:麸皮比为1∶1时产酶活性最高;菌株1适宜的培养基含水以50%最好,菌株2以70%最好;培养基初始pH均在7.0时酶活最高;发酵温度均以25℃最好,不易超过30℃;两个菌株的适宜发酵时间分别为36 h(菌株1)和72 h(菌株2).在优化发酵条件下,两个菌株单位发酵物中纤溶酶平均酶活力可分别达到1 407.25 U/g(菌株1)和953 U/g(菌株2).

The Optimalization of Solid Fermentation Factors of Two Nattokinase Producing Strains

In this study,we separated two excellent nattokinase producing strains from the traditional soybean diets;Then we tested the factors influencing the nattokinase activity at the solid fermentation culture,these factors include the carbon source/nitrogen source rate,the midium pH,the culture temperature and times.The results shows that the strain 1 suitable carbon source/nitrogen source rate were 3∶1,else the strain 2 were 1∶1.The media suitable water content were 50 %(strain1)and 70 %(strain2)respectively.The suitable primarily pH value were all 7.0 and the best culture temperature for two strains were all 25～30 ℃,and the suitable culture time of them were 36 h(strain 1)and 72 h(strain2) respectively.At the suited solid fermentation conditions,the highest nattokinase activity of strain 1 was 1 407.25 U /g and 953 U /g respectively.