OPTIMAL CONDITIONS FOR PRODUCTION OF DEXTRANSUCRASE FROM LEUCONOSTOC-MESENTEROIDES NRLL B-512F AND ITS PROPERTIES

Dextransucrase production from Leuconostoc mesenteroides NRRL B-512F w as carried out in batch cultures under different conditions in static culture conditions. Small changes in the temperature had a significant effect on the enzyme production. A temperature of 23 degrees C gave t he maximum yield of the enzyme. An increase in the temperature to 25 d egrees C reduced the enzyme activity by 28%, while a decrease in the t emperature to 20 degrees C caused 17% reduction. Static flask culture favored the dextransucrase production as compared to the shaken flask culture. The enzyme activity in the static flask was 30% higher than t he activity in rotary shaken flask culture. The dextransucrase was pur ified by three successive steps of precipitation using PEG 400. Purifi ed dextransucrase exhibited maximum activity at 30 degrees C, pH 5.2 a nd 10% of the substrate sucrose. Among the various stabilizers used (g lycerol, PEG 8000, dextran and tween 80), glycerol provided maximum st ability to the enzyme against the activity losses at temperatures 0 de grees C and 30 degrees C.