GalX regulates the d-galactose oxido-reductive pathway in Aspergillus niger

Galactose catabolism in Aspergillus nidulans is regulated by at least two regulators, GalR and GalX. In Aspergillus niger only GalX is present, and its role in d-galactose catabolism in this fungus was investigated. Phenotypic and gene expression analysis of a wild type and a galX disruptant revealed that GalX regulates the d-galactose oxido-reductive pathway, but not the Leloir pathway in A. niger.

► Aspergillus niger only contains one of the two galactose regulators previously identified in Aspergillus nidulans.
► A. niger GalX does not regulate the Leloir pathway.
► A. niger GalX controls the d-galactose catabolic oxido-reductive pathway.