In order to improve the conversion efficiency of lactic acid from cellulose

the spores containing cellobiase with high activity from Aspergillus niger ZU-07 and the cells of Lactobacillus delbrium were embedded together into calcium alginate gel beads

and the formed coimmobilized cell system was coupled with the enzymatic hydrolysis of cellulosic material to set up a novel coupling bioreactor.The research results showed that the cellobiose in the hydrolysate was converted to glucose rapidly by the cellobiase in the coimmobilized cells

and the glucose was utilized rapidly by L.delbrium to produce lactic acid.Therefore

the feedback inhibition on cellulase caused by cellobiose and glucose was eliminated effectively.When the hydrolysis temperature and fermentation temperature were controlled at 50℃ and 48℃

respectively

and the volume ratio of the coimmobilized cells to the column reactor was 40%

the produced lactic acid concentration and the yield of lactic acid from cellulose were 55.7 g·L-1 and 91.5%

respectively.Under the fed-batch process

the final concentration of lactic acid and productivity increased to 106.7 g·L-1 and 1.270 g·L-1·h-1

respectively

while the dosage of cellulase per gram substrate reduced by 25%.