PRODUCTION OF POLY(MALIC ACID) FROM DIFFERENT CARBON-SOURCES AND ITS REGULATION IN AUREOBASIDIUM-PULLULANS

Aureobasidium pullulans CBS 591.75 produced poly(malic acid) (PMA) fro m glucose, sucrose and succinate. A suitable glucose concentration for PMA production was about 50 g/L. Trifluoroacetic acid inhibited while malonate, maleate, succinate and malate increased the production of P MA; for example supplementation of succinate up to 6.5 g/L to the medi um for example increased PMA production by 44%. Go-feeding of trifluor oacetic acid plus succinate or malate relieved the inhibition by trifl uoroacetic acid. These results showed that PMA synthesis is probably r elated to the citric acid cycle and also indicated that isocitrate lya se and malate synthase participate in PMA biosynthesis.