PRODUCTION OF L-MALIC ACID FROM FUMARIC-ACID BY RESTING CELLS OF BREVIBACTERIUM SP

The ability of the resting cells of Brevibacterium sp. B2D, a floccule nt strain, to convert fumaric acid to L-malic acid was investigated un der different fermentation conditions. The optimal temperature for the bioconversion is approx 36 degrees C, and the optimal pH is around 6. 4. The bacteria do not require special cultural conditions for the dev elopment of fumarase. Ln the presence of relatively high concentration s of fumarate (60 g/L), the bacterial cells exhibited a high rate of L -malic acid production with high yield without the coproduction of unw anted byproducts like succinic acid. A yield of 89.8% of L-malic acid from fumaric acid and an average specific productivity of 0.41 g/g/h w as obtained. The presence of surfactant, even at low concentrations li ke 0.02%, resulted in over a twofold increase in specific malic acid p roduction rate.