| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing lactic acid by such a continuous fermentation process that its high productivity can be maintained stably over a long period of time under simple operating conditions. SOLUTION: The method comprises separating a fermented culture liquid of prokaryotic microorganisms having the ability to produce lactic acid through a separation membrane into a filtrate and an unfiltrate, and retrieving lactic acid as the desired fermentation product from the filtrate while the unfiltrate is held in or refluxed into the fermented culture liquid. As the separation membrane, a hard-to-close specific porous membrane having both high permeability and cell-blocking ability is used, and a filtration treatment is conducted under a specific low intermembrane differential pressure, thus enabling the production efficiency of the objective lactic acid by fermentation to be markedly improved stably at low cost. COPYRIGHT: (C)2008,JPO&INPIT |
