Experiments on cultures without carbon source to prevent catabolite repression
revealed that N-acetylglucosamine is the best inducer of chitinase (103).
The presence of readily metabolizable carbon sources like glucose, cellobiose, xylobiose, or xylose represses the synthesis of xylanase enzymes for the utilization of certain carbon sources such as xylan or cellulose and the process is known as catabolite repression
. In filamentous ascomycetes, glucose repression is known to be mediated by Cre1.
This phenomenon is known as nitrogen catabolite repression
In addition, the use of SSF for enzyme production has many advantages over submerged fermentation due to its simple technique, low capital investment, lower levels of catabolite repression
and better product recovery (Considine et al., 1989).
Furthermore, pseudo-continuous fermentation in the co-culture system allows us to use a wide range of dilution rates and to prevent the diauxic kinetics caused by the xylose catabolite repression
associated with S.
Although the strain showed a high-level tolerance to 2dg, FFH production was still under catabolite repression
. The enzyme produced by the mutant shares similar characteristics to FFH produced by other strains reported previously (Bourgi et al., 1986; Gancedo, 1998; Zhang et al., 2005).
cerevisiae and other yeast, growth in glucose as the carbon source represses transcription of numerous genes (termed glucose repression or carbon catabolite repression
, CCR) [1,2].
Below 25[degrees]C enzyme activity was less due to inappropriate incubation temperature for yeast growth, and at high temperature results in less enzyme production due to catabolite repression
of enzyme (Gomez et al., 2000; Vrabel et al., 1997; Mizunga et al., 1981; Nan et al., 1977), and due to reduce in moisture content.
This study documents catabolite repression
of prodigiosin synthesis, motility, and antibiotic susceptibility properties based upon different sugar supplemented growth conditions using S.
As Schizochytrium is a slow growing heterotroph consuming glucose at a slow rate, wai cultivation in a non carbon catabolite repression
condition or in an increased acetyl-CoA synthethase state gives rise to higher growth and glucose consumption rates (27).
The inhibition of this synthesis is called catabolite repression
(CR) and the abundance of glucose, glycerol or other readily found fermentable carbon sources inhibit this enzyme synthesis .