SIMULTANEOUS PRODUCTION AND RECOVERY OF FUMARIC-ACID FROM IMMOBILIZEDRHIZOPUS-ORYZAE WITH A ROTARY BIOFILM CONTACTOR AND AN ADSORPTION COLUMN

An integrated system of simultaneous fermentation-adsorption for the p roduction and recovery of fumaric acid from glucose by Rhizopus oryzae was investigated, The system was constructed such that growing Rhizop us mycelia were self-immobilized on the plastic discs of a rotary biof ilm contactor during the nitrogen-rich growth phase, During the nongro wth, production phase, the biofilm was alternately exposed to liquid m edium and air upon rotation of the discs in the horizontal fermentatio n vessel. The product of fermentation, fumaric acid, was removed simul taneously and continuously by a coupled adsorption column, thereby mod erating inhibition, enhancing the fermentation rate, and sustaining ce ll viability, Another beneficial effect of the removal of fumaric acid is release of hydroxyl ions from a polyvinyl pyridine adsorbent into the circulating fermentation broth. This moderates the decrease in pH that would otherwise occur, Polyvinyl pyridine and IRA-900 gave the hi ghest loading for this type of fermentation, This fermentation system is capable of producing fumaric acid with an average yield of 85 g/lit er from 100 g of glucose per liter within 20 h under repetitive Fed-ba tch cycles, On a weight yield basis, 91% of the theoretical maximum wa s obtained with a productivity of 4.25 g/liter/h. This is in contrast to stirred-tank fermentation supplemented with calcium carbonate, whos e average weight yield was 65% after 72 h with a productivity of 0.9 g /liter/h. The immobilized reactor was operated repetitively for 2 week s without loss of biological activity.