EFFECTS OF DIFFERENT CARBON-SOURCES ON THE SYNTHESIS OF PECTINASE BY ASPERGILLUS-NIGER IN SUBMERGED AND SOLID-STATE FERMENTATIONS

A study was made to compare the production of pectinase by Aspergillus niger CH4 in solid-state (SSF) and submerged (SmF) fermentations. Pro duction of endo- (endo-p) and exo-pectinase (exo-p) by SSF was not red uced when glucose, sucrose or galacturonic acid (up to 10%) were added to a culture medium containing pectin. Moreover, both activities incr eased when concentrations of the carbon sources were also increased. I n SmF, these activities were strongly decreased when glucose or sucros e (3%) was added to culture medium containing pectin. The addition of galacturonic acid affected endo-p activity production to a lesser exte nd than exo-p. Final endo-p and exo-p activities in SSF were three and 11 times higher, respectively, than those obtained in SmF. The overal l productivities of SSF were 18.8 and 4.9 times higher for endo-p and exo-p, respectively, than those in SmF. These results indicate that re gulatory phenomena, such as induction-repression or activation-inhibit ion, related to pectinase synthesis by A. niger CH4 are different in t he two types of fermentation.