ARABINOSE UTILIZATION BY XYLOSE-FERMENTING YEASTS AND FUNGI

Various wild-type yeasts and fungi were screened to evaluate their abi lity to ferment L-arabinose under oxygen-limited conditions when grown in defined minimal media containing mixtures of L-arabinose, D-xylose , and D-glucose. Although all of the yeasts and some of the fungi cons umed arabinose, arabinose was not fermented to ethanol by any of the s trains tested. Arabitol was the only major product other than cell mas s formed from L-arabinose; yeasts converted arabinose to arabitol at h igh yield. The inability to ferment L-arabinose appears to be a conseq uence of inefficient or incomplete assimilation pathways for this pent ose sugar.