PROCESS FOR THE PRODUCTION OF L-LACTATE THROUGH FERMENTATION OF WHEY WITH LACTOCOCCUS LACTIS SUBSPECIES LACTIS

摘要

In the present invention a process is described for the production of L-lactate through fermentation of whey with Lactococcus lactis subspecies lactis. Said process comprises (a) the stage of inoculation of the culture medium with Lactococcus lactis subspecies lactis, (b) the stage of production and accumulation of L-lactate in the culture medium, and (c) the stage of extraction of a given volume of fermented broth from the biological reactor. Fermentation in the culture medium takes place at a constant temperature lying in the range from 22 to 29°C, under strict anaerobic conditions and at a pH in the range from 5 to 6. Such operating conditions determine the homofermentative pathway of Lactococcus lactis subspecies lactis, in this manner preventing the generation of byproducts differing from the L-lactate, permitting total use of the lactose, preventing the accumulation of glucose and galactose in the fermented culture medium. Finally, the fermented culture medium is recovered from the fermentation vessel having a minimum concentration of L-lactate of 20 g/l and an optical purity exceeding 90%, together with a concentration not exceeding 0.3 g/l of byproducts differing from L-lactic acid and/or any of the monosaccharides constituting lactose.