Rosfarizan M, Ariff A B, Hassan M A, Karim M I
Department of Biotechnology, Universiti Putra Malaysia, Selangor.
Folia Microbiol (Praha). 1998;43(5):459-64. doi: 10.1007/BF02820791.
Direct conversion of gelatinized sago starch into kojic acid by Aspergillus flavus strain having amylolytic enzymes was carried out at two different scales of submerged batch fermentation in a 250-mL shake flask and in a 50-L stirred-tank fermentor. For comparison, fermentations were also carried out using glucose and glucose hydrolyzate from enzymic hydrolysis of sago starch as carbon sources. During kojic acid fermentation of starch, starch was first hydrolyzed to glucose by the action of alpha-amylase and glucoamylase during active growth phase. The glucose remaining during the production phase (non-growing phase) was then converted to kojic acid. Kojic acid production (23.5 g/L) using 100 g/L sago starch in a shake flask was comparable to fermentation of glucose (31.5 g/L) and glucose hydrolyzate (27.9 g/L) but in the 50-L fermentor was greatly reduced due to non-optimal aeration conditions. Kojic acid production using glucose was higher in the 50-L fermentor than in the shake flask.
利用具有淀粉酶的黄曲霉菌株将糊化西米淀粉直接转化为曲酸，在250毫升摇瓶和50升搅拌罐发酵罐中进行了两种不同规模的深层分批发酵。为作比较，还以葡萄糖和西米淀粉酶解产生的葡萄糖水解产物作为碳源进行发酵。在淀粉的曲酸发酵过程中，在活跃生长阶段，淀粉首先通过α-淀粉酶和糖化酶的作用水解为葡萄糖。然后在生产阶段（非生长阶段）剩余的葡萄糖被转化为曲酸。在摇瓶中使用100克/升西米淀粉生产曲酸（23.5克/升）与葡萄糖发酵（31.5克/升）和葡萄糖水解产物发酵（27.9克/升）相当，但在50升发酵罐中由于曝气条件不理想，产量大幅降低。在50升发酵罐中使用葡萄糖生产曲酸的产量高于摇瓶中的产量。
