代谢副产物对L-苏氨酸发酵的影响及应对措施

The Effects of Byproducts on L-Threonine Fermentation and Resolved Schemes

研究了L-苏氨酸的发酵过程,通过高效液相色谱和氨基酸分析仪测定了L-苏氨酸发酵液中的主要副产物为乙酸、乳酸、缬氨酸、天冬氨酸、丙氨酸等。利用外源添加实验研究了各种代谢副产物对L-苏氨酸发酵的影响。结果表明乙酸浓度高于2 g/L、乳酸浓度高于10 g/L时对L-苏氨酸生产菌的生长和产酸有抑制作用,采用提高溶解氧和葡萄糖限制性脉冲流加措施将乙酸、乳酸的浓度控制在0.5 g/L以下,L-苏氨酸产量明显提高。

The process of L-threonine fermentation was investigated and the main byproducts in the liquor of L-threonine were acetic acid, lactic acid, valine, alanine and aspartic acid analyzed by HPLC and amino acid analyzer. The effects of all byproducts were studied and the results showed that 2 g/L acetate acid, 10 g/ L lactic acid inhibited the growth of L-threonine producer and the production of L-threonine. Treatments for improving the value of dissolved oxygen and glucose-limited pulse fed-batch were used to reduce the accumulation of byproducts and a good production of L-threonine was obtained.