Toray Industries, Inc.

Ito Masateru

Katsushige Yamada

Kenji Sawai

Kenji Kawamura

Hideki Sawai

Takashi Mimitsuka

Shin-ichi Minegishi

Tatsuya Nagano

Izumi Nakagawa

Lactic acid is obtained by a method including (A) a step of continuous fermentation wherein a fermentation culture medium of a microorganism having an ability of lactic acid fermentation is filtered through a porous membrane having an average pore size of not less than 0.01 &#x3bc;m and less than 1 &#x3bc;m with a transmembrane pressure difference within the range of 0.1 to 20 kPa, and the permeate is collected, while retaining the non-permeated liquid in or returning the non-permeated liquid to the culture, and adding a fermentation feedstock to the culture; (B) a step of filtering the permeate obtained in Step (A) through a nanofiltration membrane; and (C) a step of distilling the permeate obtained in Step (B) under a pressure of not less than 1 Pa and not more than atmospheric pressure, at 25&#xb0; C. to 200&#xb0; C. to recover lactic acid.

Method for producing lactic acid and method for producing polylactic acid

Growing community of inventors

Kamakura, Japan

Ito Masateru