Abstract: In a microbial process for producing 2-keto-L-gulonic acid (hereinafter sometimes referred to as 2KGA) by fermentation or microbial cell reaction with at least one microorganism capable of producing 2KGA, wherein the improvement comprises taking out, from the fermentation broth or microbial cell reaction mixture, the produced 2KGA alone or together with a low molecular-weight cation as the counter ion by electrodialysis.

Abstract: A method for producing 2-keto-L-gulonic acid (hereinafter referred to as 2KGA) which comprises(1) culturing a microorganism capable of producing 2KGA from L-sorbose, in a liquid culture medium containing a substrate to produce 2KGA and(2) recovering the produced 2KGA, while recovering the microorganism in the culture broth,(3) inoculating the recovered microorganism to a new liquid culture medium for the following culture and(4) repeating said culture and recovering at least once.The present invention provides an industrially advantageous, versatile method for producing 2KGA that shortens the overall culture time, and reduces the amounts of starting medium materials and culture waste.