Development of Integrated Lactic Acid Total Fermentation Processes

在本研究计画中，我们开发了一套完整的乳酸发酵系统，包含细胞循环发酵系统与下游分离流程。（1）建立了陶瓷膜高密度细胞培养体系，细胞密度可达183g干重/L，细胞活力高。(2)开发了一套完整的发酵系统，包括细胞循环系统和分离过程。作为分离工艺，我们考虑使用使用Alamin 336作为萃取剂（使用油醇作为溶剂）的萃取工艺。结果表明，确定发酵和提取的pH值（4.2 - 4.5）对整个系统的优化是非常重要的，此外，我们还考虑使用离子交换树脂作为分离单元。结果表明，该系统可实现高细胞密度培养和高底物产量。(3)开发了一种集成的在线传感器系统，用于在线测量葡萄糖和乳酸。(4)研究了在线优化控制系统。(5)以长B. longum和费氏丙酸杆菌（P.freudenreichii）为原料，采用混合培养体系，研究了反应器的新活性。(6)研究了微生物的呼吸链和能量产率。

In the present research project, we developed an integrated lactic acid fermentation system which contains cell recycle fermentation system and the down-stream separation processes. In association with this system, we also investigated the related other research topics, Namely :(1) High cell density culture system was developed with ceramic membrane, and 183 g-dry cell weight/L could be attained with high cell viability.(2) The integrated fermentation system was developed which contains cell-recycle system and separation process. As the separation process, we considered to use extraction process using Alamin 336 as an extractant (oleyl alcohol was used as the solvent). It was shown to be quite important to find the pH values (4.2-4.5) for fermentation and extraction for the optimisation of total system.Furthermore, we considered to use ion-exchange resin as the separation unit. It was shown that high cell density culture with high substrate yield could be attained with this system.(3) An integrated on-line sensor system was developed to measure glucose and lactate on-line.(4) On-line optimising control system was investigated.(5) Mixed culture system using B.longum and P.freudenreichii was investigated to study the new activity of the reactor.(6) Respiratory chain and the energy yield were investigated for microorganisms.