AMMONIUM LACTATE FROM DEPROTEINIZED ALFALFA JUICE BY STREPTOCOCCUS-FAECIUM

Deproteinized alfalfa juice is a by-product of the mechanical fractionation of alfalfa to obtain protein. In this work the juice was used as the substrate for the production of ammonium lactate (l-lactic acid) by a strain of Streptococcus faecium. Batch fermentation with a constant pH of 5.8 gave 27.2 g/l of lactic acid (90% conversion and 1.1 g/l/h productivity) and 6×1012 cells/l after 24 h. Semicontinuous fermentation allowed the conversion of 3-times the volume of deproteinized juice after 44 h, finally giving 29.7 g/l of ammonium lactate (99% conversion and 2.5 g/l/h productivity) and 4-6×1012 cells/l.