METHOD FOR PRODUCTION OF LACTIC ACID AND LACTIC ESTERS

摘要

A method for producing a lactic ester inexpensively by microorganic fermentation of lactic acid with a simple apparatus is provided, which method effects adjustment of the pH of a culture medium during the course of the fermentation with ammonia and, after the end of the fermentation, recovers the ammonia for reuse to lower the cost required for the fermentation and decrease the amount of a by-product of fermentation. In a process involving fermentation of lactic acid with a microorganism, a method for the production of a lactic ester which comprises carrying out the adjustment of pH of a culture medium undergoing the fermentation of lactic acid with ammonia, adding an alcohol having four or five carbon atoms to at least one solution selected from the group consisting of a solution of ammonium lactate obtained by the fermentation, the concentrate of the solution of ammonium lactate mentioned above, and the solution resulting from separation of solid substances including the microorganic cells used for the fermentation from either of the solutions and heating the resultant mixture thereby inducing dehydration and esterification of lactic acid with the alcohol and, at the same time, effecting liberation and recovery of ammonia, and adding a mineral acid to the solution obtained by the esterification reaction and heating and dehydrating the resultant mixture in an acidic state thereby promoting and completing the esterification of the lactic acid with the alcohol.