Formulation of low-cost fermentative media for lactic acid production with Lactobacillus rhamnosus using vinification lees as nutrients.

Lees coming from different steps in white wine and red wine vinification were characterized under physicochemical analyses to determine the content in carbon, nitrogen, ashes, solids in suspension, organic compounds, and minerals. Due to the hydrolytic activity of Lactobacillus strains, lees without autolysis treatments were used directly as the unique nutrient or in combination with corn steep liquor to carry out the glucose to lactic acid fermentation with Lactobacillus rhamnosus CECT-288. Time courses of glucose and lactic acid were modeled according to reported models. Using 20 g/L of lees coming from the white wine technology and re-collected after the second decanting step before distillation, as the only nutrient, the values achieved (P = 105.5 g/L, Q(P) = 2.470 g/L.h) were even higher than those obtained with the costly MRS broth (P = 104.3 g/L, Q(P) = 2.251 g/L.h).