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Continuous production of lactic acid from deproteinized whey by coimmobilized Lactobacillus casei and Lactococcus lactis cells in a packed-bed

Roukas, T., Kotzekidou, P.
Food biotechnology 1996 v.10 no.3 pp. 231-242
bioreactors, Lactobacillus casei, Lactococcus lactis, alginates, mixtures, whey, fermentation, lactose, lactic acid, biosynthesis, milk proteins, immobilized cells, cheese whey
The continuous production of lactic acid from deproteinized whey by immobilized single and mixed culture of L. casei and L. lactis in Ca-alginate beads has been investigated. A coimmobilized culture system gave better results than immobilized single cultures regarding lactic acid concentration, productivity, yield, and lactose utilization. Maximum lactic acid productivity of 7 g/lh was obtained at D = 0.4 h-1 with a yield of 70% lactic acid and 50% lactose utilization. At a dilution rate of 0.1 h-1, a lactic acid productivity of 25 g/lh was obtained with a 55.5% lactic acid yield and 90% lactose utilization. The bioreactor system was operated at a constant dilution rate of 0.1 h-1 for 20 days without loss of original activity. In this case, the average lactic acid productivity, lactic acid yield and lactose utilization were 2.4 g/lh, 55% and 90%, respectively.