裂殖壶菌发酵产DHA油脂的生产工艺优化

Optimization of fermentation process for production of DHA oil by Schizochytrium sp.

采用磷酸香草醛法实时监测裂殖壶菌发酵产DHA油脂的积累情况,对裂殖壶菌的基础发酵工艺进行了优化。得到裂殖壶菌生长和油脂积累的最佳培养基配方为：葡萄糖30 g/L,玉米浆粉6 g/L,蛋白胨4 g/L,硝酸钠3.6-3.9 g/L,海水晶15 g/L;在50 L的发酵罐中采用后期流加一定量的葡萄糖提高碳氮比来提高油脂积累外,通过流加3.0 g/L的大豆油来刺激菌体生长,最终经过72 h的流加培养,菌体湿重达到200 g/L,总油脂含量达到60%以上,油脂脂肪酸组成中的DHA含量占22%左右。

The accumulation of DHA oil produced by Schizochytrium sp. was real - timely monitored byphosphoric acid vanillin method, and the fermentation process for production of DHA oil by Schizochytri-um sp. was optimized. The results showed that the optimal formular of culture medium for growth and oilaccumulation of Schizochytrium sp. were obtained as follows ： glucose 30 g/L, corn steep powder 6 g/L,peptone 4 g/L, sodium nitrate 3.6 - 3.9 g/L, sea crystal 15 g/L. A certain dosage of glucose was fed toincrease carbon - nitrogen ratio to improve oil accumulation and a fed batch of 3.0 g/L soybean oil couldstimulate cell growth in 50 L fermentor. After fed batch fermentation for 72 h, wet weight of cell reached200 g/L,total oil content was more than 60% and DHA content in the fatty acid composition of the oil ac-counted for about 22%.