PRODUCTION OF PECTINASES BY ASPERGILLUS-NIGER IN SOLID-STATE FERMENTATION AT HIGH INITIAL GLUCOSE-CONCENTRATIONS

Exopectinase (exo-p) and endopectinase (endo-p) production by Aspergil lus niger CH4 in solid state culture was studied at initial glucose co ncentrations of 100, 250, 350 and 450 g/l. The highest activity of exo -p (35 U/g) was produced at 72 and 120 h in the medium containing 100 and 250 g glucose/l, respectively. The maximum endo-p activity (9 U/g) was produced at 72 h in the medium with 250 g glucose/l. The reductio n in pectinase production at 350 and 450 g/l initial glucose concentra tion was due neither to repression of the synthesis of the enzyme nor to the glucose consumption rate of the strain but due to a drastic dro p in pH of the medium.