为了研究活细胞在线监控补料技术对L-羟脯氨酸发酵的影响，在30 L发酵罐上安装活细胞在线检测仪，实时监测发酵液中活细胞数量，根据活细胞数量调整补料策略，分析活细胞在线监控补料对L-羟脯氨酸发酵补糖速率、产量、糖酸转化率和代谢流量分布的影响。结果表明，采用活细胞在线监控补料发酵工艺生产L-羟脯氨酸的最佳补糖策略是在发酵中后期及时降低补糖速率，最终降到9 g/(L·h)，L-羟脯氨酸产量提高了11.39%，乙酸积累量减少了48.69%，糖酸转化率提高了14.92%，糖酵解途径和乙醛酸循环的代谢流分别减少了8.50%和16.89%，磷酸戊糖途径的代谢流增加了14.73%，乙酸合成的代谢流减少了4.97%，L-羟脯氨酸合成的代谢流提高了16.21%。上述结果说明采用活细胞在线监控补料技术生产L-羟脯氨酸，可以有效降低副产物的积累，提高L-羟脯氨酸产量及糖酸转化率。

In order to study the effect of online monitoring fed-batch fermentation of living cells on L-hydroxyproline fermentation, the live cell online monitor was used in the 30 L fermentor to monitor the number of living cells to adjust the feeding strategy, and the effect of online monitoring fed-batch fermentation of living cells on sugar supplement rate, glucose conversion rate and the metabolic flux channeled were analyzed.The results showed that the best sugar supplementation strategy for the production of L-hydroxyproline by the online monitoring of the living cells was to reduce the rate of sugar supplementation timely in the mid and later phase of fermentation, and finally to 9 g/(L·h).The production of L-hydroxyproline increased by 11.39%, the accumulation of acetic acid decreased by 48.69%, and glucose conversion rate increased by 14.92%.At the same time, the flux channeled to EMP and glyoxyl circle decreased by 8.50% and 16.89%, respectively.However, the flux channeled to HMP increased by 14.73%.The flux channeled to acetic acid decreased by 4.97%, and the metabolic flux channeled to L-hydroxyproline increased by 16.21%.These results indicated that online monitoring fed-batch fermentation of living cells could significantly reduce the accumulation of by-product, increase the production of L-hydroxyproline, and improve the glucose conversion rate.