Molecular regulation of arabinan and L-arabinose metabolism in Hypocrea jecorina (Trichoderma reesei).

Hypocrea jecorina (anamorph: Trichoderma reesei) can grow on plant arabinans by the aid of secreted arabinan-degrading enzymes. This growth on arabinan and its degradation product L-arabinose requires the operation of the aldose reductase XYL1 and the L-arabinitol dehydrogenase LAD1. Growth on arabinan and L-arabinose is also severely affected in a strain deficient in the general cellulase and hemicellulase regulator XYR1, but this impairment can be overcome by constitutive expression of the xyl1 encoding the aldose reductase.