T. Roukas et P. Kotzekidou, CONTINUOUS PRODUCTION OF LACTIC-ACID FROM DEPROTEINIZED WHEY BY COIMMOBILIZED LACTOBACILLUS-CASEI AND LACTOCOCCUS-LACTIS CELLS IN A PACKED-BED, Food biotechnology, 10(3), 1996, pp. 231-242
The continuous production of lactic acid from deproteinized whey by im
mobilized single and mixed culture of L. casei and L. lactis in Ca-alg
inate 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/1h was obtained at D=0.4 h(-1) with a
yield of 70% lactic acid and 50% lactose utilization. At a dilution ra
te of 0.1 h(-1), a lactic acid productivity of 2.5 g/1h was obtained w
ith a 55.5% lactic acid yield and 90% lactose utilization. The bioreac
tor system was operated at a constant dilution rate of 0.1 h(-1) for 2
0 days without toss of original activity. In this case, the average ta
ctic acid productivity, lactic acid yield and lactose utilization were
24 g/1h, 55% and 90%, respectively.