基于DO-stat流加培养控制的海藻糖合成酶发酵条件研究

溶氧浓度对重组大肠杆菌的生长和外源蛋白的高效表达影响较大，为进一步增加菌体量和重组蛋白表达量，该研究采用DO-stat流加培养进行控制，分别研究了溶氧浓度20%、30%、35%和40%条件下大肠杆菌的生长情况以及海藻糖合成酶的表达情况。结果表明，当发酵罐中溶氧浓度控制在30%时，发酵40 h，菌体干质量可达53.9 g/L，是分批发酵时的6倍，海藻糖转化率达到80.9%，是分批发酵时的2.25倍。

Research on trehalose synthase fermentation conditions based on DO-stat culture-feeding strategy

Dissolved oxygen concentration has great effect on recombinant Escherichia coli growth and high-efficiency expression of heterologous protein. In order to further increase the cell content and recombinant E. coli expression, DO-stat feeding strategy was adopted. The effect of dissolved oxygen concentration (20%, 30%, 35% and 40%) on E. coli growth and trehalose synthase expression were investigated respectively. Results showed that the cells dry mass reached 53.9 g/L, which was 6 times of those in fed-batch fermentation, the conversion rate of trehalose reached 80.9%, which was 2.25 times of those in fed-batch fermentation, when dissolved oxygen concentration was controlled at 30% for 40 h fermentation.