Catabolite repression of chitinase and other genes involved in utilization of carbon sources was identified in ccrA1 mutant of S.
Disruption of reg1 gene relieved the carbon catabolite repression of both [+ or -]-amy lases and chitinases indicating the involvement of reg1 (109).
Tomita, Induction and Catabolite Repression Mechanisms of Cellulase in Fungi, J.
Ramon, Carbon Catabolite Repression of the Aspergillus nidulans xlnA gene, Mol.
These results might be attributed to the fact that the presence of readily available substrates has been noted to influence the biosynthesis of many extracellular enzymes via catabolite repression
mechanism (Vijayaraghavan et al., 2011; Teodoro and Martins, 2000).
Afterwards, enzyme activity declined due to decrease in nutrients availability in the medium, or carbon catabolite repression, as the expression in yeast is checked by the presence of monosaccharides like glucose and fructose as reported by Samia (2008).
As monosaccharide concentration in the medium decreased to a value below 0.2 mg/ml, carbon catabolite repression was halted resulting in a faster rate of enzyme biosynthesis as reported by Roitsch et al.
These results appear to support catabolite repression
by glucose and sorbitol with prodigiosin production.
The decreased activity in the later phase of growth was probably due to catabolite repression
by glucose released from starch hydrolysis.
Enzyme production regulation is influenced by catabolite repression
. Reduction in enzyme production was observed in the presence of EDTA while addition of tween 20 and CaCl2 helped to enhance the enzyme production.
Decrease in biomass with high xylose concentration may be due to catabolite repression
during aerobic metabolism.