棒曲霉Asp-195v产蛋白酶条件的优化

The Optimal Liquid Fermentation Conditions for Protease Production by Asp-195v

[目的]优化高产蛋白酶棒曲霉Asp-195v的发酵条件。[方法]利用正交设计方法研究培养基成分配比、含水量、初始pH值、培养时间、接种量和培养温度等发酵条件对棒曲霉Asp-195v产蛋白酶的影响。[结果]影响该菌株产酶的最主要因素是培养时间,其次是温度,其他4个因素对该菌株产酶影响较小。该菌株最适产酶条件为:培养基成分中麸皮和豆粕比例为7∶3(总量为10g),含水量为90ml(250ml三角瓶),pH值为7,培养时间为72h,接种量为1.5ml,培养温度为24℃,摇床转数为120r/min。棒曲霉Asp-195v对盐有一定耐受力,其中24%NaCl中的蛋白酶与空白样品相比仍有47.6%的活性。[结论]该菌株在豆酱生产中具有良好的应用价值。

[Objective]The aim was to optimize fermentation conditions for protease production by Asp-195v.[Method]The liquid fermentation conditions for protease production of the strain Asp-195v of Aspergillus clavatus were studied by orthogonal design method,which included medium constituent,water content,initial pH value,inoculum amount,fermentation time and temperature in 250 ml shaking bottle. [Results]The results showed that the main factor affecting protease production was fermentation time. The optimal liquid fermentation conditions in shaking bottles were as follows： the ration of bran and bean cake was 7∶3（10 grams of total）,water 90 ml,initial pH 7,inoculum amount was 1.5 ml,fermentation time was 72 h,fermentation temperature was 24 ℃,rotation speed was 120 r/min. The strain Asp-195 was able to produce protease in different salinity conditions,which had a certain degree of tolerance to salt,its protease activity in 24%NaCl was 47.6% compared to the blank test without NaCl.[Conclusion] The strain had a good application value in the miso production.