[L-lactic acid fermentation by immobilized Rhizopus oryzae in a three-phase fluidized-bed]

L-lactic acid fermentation in a three-phase fluidized-bed bioreactor was studied by using immobilized Rhizopus oryzae cells with polyurethane particles as supporter. The results indicated that the immobilized cells were stable after used for 8 batches repeatedly. The rate and the yield of lactic acid fermentation with glucose as carbon source were 19.1 g h-1.L (bead)-1 and 82.5%, respectively. With the hydrolyzate of corn cob residue from xylose manufacturer by cellulase hydrolysis, the yield of lactic acid reached 71.9%.