利用Crypthecodinium cohnii高密度发酵生产DHA的流加策略研究

利用流加策略实现了隐甲藻(Crypthecodinium cohnii)生产DHA的高密度发酵。根据隐甲藻间歇式发酵的特性,探讨最佳补料时间及流加液中最佳碳氮比,结果表明,在葡萄糖浓度降至4g/L左右时流加碳氮比为30∶1的营养液对隐甲藻的生长和脂肪酸积累最有利。根据以上结果,初始葡萄糖浓度25g/L,采用5d连续发酵多次流加策略,细胞干重达6.37%,DHA产量为4.08g/L。

Fed-batch Strategy Study on High Density DHA Fermentation by Crypthecodinium cohnii

A fed-batch process was developed for the high density culture of DHA production by Crypthecodinium cohnii. According to the characteristic of batch fermentation of C.cohnii, the optimal feeding time and optimal C to N ratio of nutrient fluid were discussed. The results showed that feeding nutrient fluid which C/N ratio was 30:1 when glucose concentration dropped to approximately 4 g/L was the most advantageous for the growth of C.cohnii and accumulation of fatty acid. On the basis of results above, when the initial glucose concentration wad 25 g/L and feeding nutrient fluid at the period of five days culture, the maximal cell dry weight and DHA yield obtained was 6.37% and 4.08 g/L respectively.