Chrysosporium lucknowense arabinohydrolases effectively degrade sugar beet arabinan

The filamentous fungus Chrysosporium lucknowense (C1) is a rich source of cell wall degrading enzymes. In the present paper four arabinose releasing enzymes from C1 were characterized, among them one endoarabinanase, two arabinofuranosidases and one exoarabinanase. Combinations of these enzymes released up to 80% of the arabinose present in sugar beet arabinan to fermentable monosugars. Besides the main product arabinobiose, unknown arabinose oligomers are produced from highly branched arabinan when endoarabinanase was combined with exoarabinanase and/or arabinofuranosidase. All described arabinose releasing enzymes are temperature stable up to 50 °C and have a broad pH stability. This makes C1 arabinohydrolases suitable for many biotechnical applications, like co-fermentation bioethanol production.