BACKGROUND: High glucose and ethanol tolerance is among the most important requirements of ethanol-producing microorganisms. The purpose of this study was evaluation of filamentous fungus Mucor hiemalis for ethanol production from wheat and starch hydrolysates with high glucose concentration.
RESULTS: The results showed high tolerance of the fungus in fermentation of the hydrolyzates with high glucose concentrations (as high as 190 g L−1). Interestingly, increasing the glucose concentration from 15 to 190 g L−1 was accompanied by enhancement of initial sugar uptake rate. Ethanol was the most important metabolite obtained during all fermentations and its concentration reached over 50 g L−1. Beside ethanol, chitosan was another valuable product of the process. Glucosamine, a precursor of chitosan, made up 37.3–46.7% of the cell wall of this fungus.
CONCLUSIONS: M. hiemalis is a promising microorganism for simultaneous production of ethanol and chitosan from substrates with high sugar concentrations. © 2012 Society of Chemical Industry