Production of lactic acid and probiotics on waste products of food and agricultural industry

Lactic acid is industrially important product with versatile applications in food, pharmaceutical, cosmetic, textile and leather industry and for the production of chemicals and biodegradable polymers. The main goal of this project is to examine the production of lactic acid and probiotic biomass on waste products of food and agricultural industry. The most available renewable biomass in Serbia such as thin stillage retained from distillery after the production of bioethanol from corn and triticale, brewery spent grains and whey, waste cereal grains, and other agricultural wastes will be examined as feedstocks for the production of lactic acid. An optimal preparation of these raw materials to obtain adequate substrates for lactic acid fermentation will be determined and the selection of the most productive microbial strains from Lactobacillus, Lactococcus and Streptococcus genera will be performed. With the selected strains, the conditions for lactic acid fermentation and the production of probiotic biomass will be optimized. The following parameters will be examined: media composition, inoculums’ concentration, addition of activators, temperature, pH, process kinetics and the probiotic activity. In order to establish a productive and economical process, the use of immobilized and free lactic acid bacteria with or without biomass recycling, as well as application of different process integration scheme (SSF versus SHF, etc) will be assessed.