马铃薯淀粉直接发酵制备L(+)—乳酸工艺过程研究

利用马铃薯淀粉直接作为碳源,米根霉AS3.819为菌种,不经过液化和糖化过程,在5L发酵罐中直接发酵生产L（＋）-乳酸。其发酵最优工艺条件：140g/L马铃薯淀粉经微波快速灭菌系统灭菌后直接投入发酵罐,发酵温度32℃,选用轻质碳酸钙为中和剂,以流加方式控制pH为5.1～5.2,平均产酸为16.15g/L,发酵周期为72h。探索出利用马铃薯淀粉为原料直接发酵制备L（＋）-乳酸的生产工艺条件,为综合利用淀粉质等生物质原料进行生物转化奠定了基础,并拓宽和增加了发酵生产L（＋）-乳酸的原料来源渠道,降低L（＋）-乳酸的生产成本,为大规模工业化生产L（＋）-乳酸提供了科学依据。

The production of L-lactic acid from potato starch by direct fermentation using Rhizopus oryzae AS3.819 was studied.The optimum process conditions were as follows： 140g/L potato starch which was sterilized by microwave sterilizing system, temperature was 32%）, neutralizing agent was calcium carbonate; pH was 5.1 -5.2. The yield of L-lactic acid was 16.15g/L, the incubation time was 72h. Finally, the process conditions establish foundation of biotransformation for utilizing starchiness, expand raw material source, and reduce cost of producing lactic acid. And the process conditions of producing L-lactic acid from potato starch were established and provide the scientific foundation for commercial process.