There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.
Abstract
The expression of the feruloyl esterase gene faeA, the alpha-glucuronidase gene aguA,
the endoxylanase gene xlnB, and the beta-xylosidase gene xlnD from Aspergillus niger
on xylose was studied in a wild-type strain and in a CreA mutant. A decrease in expression
of all four genes was observed with increasing xylose concentrations in the wild-type
strain, whereas expression levels in the CreA mutant were not influenced. The results
in the wild type indicated that xylose concentrations higher than 1 mM resulted in
repression of the expression of the xylanolytic genes tested mediated by the carbon
catabolite repressor protein CreA. On xylose, the expression levels of the xylanolytic
genes were therefore not only determined by induction via XlnR, but also by repression
via CreA. The genes tested were not influenced to the same extent by XlnR or CreA,
resulting in specific expression levels and patterns for each individual gene.