Continuous Fermentation Of Lactic Acid By Immobilized R.oryzae In Membrane Bioreactor

A submerged membrane bioreactor was developed for fermentation to produce L(+)-lactic acid by Rhizopus oryzae, but Rhizopus oryzae will grow on the surface of membrane during the lactic acid fermentation in SMBR. The author advised to unite the immobilized celles technology and SMBR to decrease the membrane fouling and simplify lactic acid separation.An immobilized fibrous-bed bioreactor was developed for fermentation to produce L (+)-lactic acid from glucose by Rhizopus oryzae. The aeration rate and immobilized area were found to have significant effects on lactic acid productivity and yield, with the optimalcondition aeration rate 1.0vvm and immobilized area 400cm2, A high lactic acid production rate of 2.13g/(L?h) and the final concentration of 73.1g/L with a high optical purity of 98.9% were obtained from glucose. Oxygen transfer rate during the fermentation was also studied and the results showed that mycelia layer have an effect on lactic aicd production.When immobilized fibrous-bed is used in the continuous lactic acid production in SMBR, on the steady state the lactate production is 1.91g/(L?h). Using the mycelial pellets for continuous lactic acid production in SMBR was also studied for 87h fermentation in SMBR, 50.9g/L lactic acid was achieved and the production was 3.05g/(L?h).