The pentose catabolic pathway (a), the Leloir pathway (b) and the oxido-reductive pathway (c) that convert arabinose, xylose and galactose.

The enzymes that catalyse particular metabolic steps in A. nidulans (white boxes), T. reesei (light grey boxes) and A. niger (dark grey boxes) are indicated. In the oxido-reductive pathway in A. nidulans the product of galactitol oxydation is most likely L-sorbose, while in A. niger and T. reesei this product was characterised as L-xylo-3-hexulose [13,14]. Unidentified or unconfirmed enzymes are marked with a star. Gene numbers of A. nidulans enzymes: LarA = AN7193, LadA = AN0942, LxrA = AN10169, XdhA = AN9064, XyrA = AN0423, XkiA = AN8790, GalE = AN4957.3, GalD = AN6182.3, GalF = 9148.3, GalG = AN4727.3, PgmB = AN2867.3, XxkA = AN7459. Gene numbers of A. niger enzymes: XyrA = An01g03740, LadB = An16g01710, XhrA = An16g01650, SdhA = An07g01290, HxkA = An02g14380.