[Induction of cellulases and xylanases in Aureobasidium pullulans]

The specificity or induction of wood-degrading enzymes using series of mono, di or polysaccharides as carbon source for the yeasts Geotrichum candidum and Trychosporon penicillatum and the yeast-like organism Aureobadidium pullulans were studied. The strain A. pullulans was the only one that when xylan or "steam exploded wood" were used as carbon source all the enzymes tested were found. This strain was unable to grow on carboxymethyl or Avicel cellulose. D-xylose was the nutritional inducer of beta-xylosidase and beta-xylanase but D-glucuronic acid induced CMCase activity and beta-glucosidase was produced with every carbon source. The 1,4 beta-xylobiose was not an inducer of beta-xylanase but with the structural 1,2-beta- and 1,3-beta-xylobiose isomers high levels of this enzyme were obtained.