Only arabinose was unused. Addition of 10 mg/l zinc to acid hydrolyzate did not affect peak ethanol production, but it did increase rates of sugar utilization and ethanol production. The fermentation of hydrolyzate with recycled cells of C. shehatae Y-049 reduced the fermentation lag and increased the final ethanol concentration. The ethanol production rate was optimum in the pH range of 5.5±6.0, and an ethanol yield of 0.41±0.46 g/g was obtained in these fermentations. Because of heterogeneity between wood hydrolyzate batches, ethanol production was found to be in¯uenced by hydrolyzate composition, pH, acetate concentration, amount of cells, and recycling of cells. Published by Elsevier Science Ltd.