摘要
通过分析核黄素产生菌E .ashbyii在发酵过程中菌体量、糖质量浓度、pH值、核黄素质量浓度和粘度的变化及菌体形态与核黄素生物合成之间的联系 ,发现 pH值对菌体生长有显著的影响 ,菌体浓度过高会导致发酵液粘度过大 ,通风供氧困难 ,菌体活力下降 .采用先低浓度培养菌体 ,然后根据发酵液 pH值的变化进行多次适量补料 ,不仅可以控制菌体的过度增殖 ,缓解通风供氧不足造成的困难 ,而且还可以保持菌体活力 ,增加核黄素的产量 .
By analyzing biomass, saccharide, pH, riboflavin and viscosity of the broth during riboflavin producing strain E.ashbyii fermentation process and the relationship between the strain profile and riboflavin biosynthesis, it was found that pH has great effect on the strain reproducing and higher biomass leading to higher viscosity of the broth which resulted in difficulties on broth aeration and lower activity of the strain. By culturing E.ashbyii with lower nutrient then feeding the broth with higher nutrient culture several times according to the pH of the broth, not only over-reproducing of the strain could be avoided, the difficulties of broth aeration be alleviated and higher activity of the strain be maintained, but also the yield of riboflavin could be improved.
