Regulation of Pentose Catabolic Pathway Genes of Aspergillus niger

The aim of this study was to obtain a better understanding of the pentose catabolism in Aspergillus niger and the regulatory systems that affect it. To this end, we have cloned and characterised the genes encoding A. niger L-arabitol dehydrogenase (ladA) and xylitol dehydrogenase (xdhA), and compared the regulation of these genes to other genes of the pentose catabolic pathway. This demonstrated that activation of the pathway depends on two transcriptional regulators, the xylanolytic activator (XlnR) and an unidentified L-arabinose specific regulator (AraR). These two regulators affect those genes of the pentose catabolic pathway that are related to catabolic conversion of their corresponding inducers (D-xylose and L-arabinose, respectively).