黑曲霉改良株C112产β-葡萄糖苷酶的诱导及条件优化

Induction and optimization of conditions for producing β-glucosidase by the improved strain Aspergillus niger C112

利用单因素实验及均匀设计法研究了黑曲霉C112发酵产β-葡萄糖苷酶的发酵条件。结果表明:黑曲霉C112发酵产β-葡萄糖苷酶的影响因素很多,包括接种方式(菌株活力)、接种量、碳氮源种类与浓度、发酵温度时间、初始pH值等。研究发现,通过种子接种改善菌株活力能有效提高产酶活力。碳源粒径也是影响诱导产酶效果的重要条件之一,当玉米芯粒径高于0.180 mm时产酶效果最佳。该菌株最适宜产酶条件为:玉米芯与麦芽浸粉(7:3)6 g/L、初始pH值4.87、30℃下发酵120 h,所得酶活力最大可达12.925 U/mL,较优化前提高了79.0%。

Single factor experiment method and uniform design methodology were applied to optimize the fermentation of Aspergillus niger C112 for β-glucosidase. Many factors affected the fermentation of β-glucosidase, including the inoculation method （the vitality of strains）, inoeulum concentration, type and concentration of carbon and nitrogen sources, fermentation time and temperature, and initial pH, et al. The results show that the seed inoculation effectively improved the strains vitality and thus raising the enzyme production capacity; One of important factors which affected the enzyme production was the carbon particle size; Higher β-glucosidase activity was obtained when corn-core particle diameter was greater than 0.180 ram; The optimal fermentation conditions were as follows： corn- core 42 g/L, malt extract 18 g/L, initial pH 4.87, cultivation for 120 hours under the temperature of 30 ℃. With the optimal fermentation conditions, the ultimate β-glucosidase activity reached to 12.925 U/mL, increasing by 79.0 % than before.