Ethanol production from Jerusalem artichoke tubers (Helianthus tuberosus) usingKluyveromyces marxianus andSaccharomyces rosei

Abstract
This article examines the potential of Jerusalem artichoke as a source for ethanol and single‐cell protein SCP. In addition, experimental results are presented on batch fermentation kinetics employing two strains of Kluyveromyces marxianus and one strain of Saccharomyces rosei grown on the extract derived from the tubers of Jerusalem artichoke. Of the three cultures examined, Kluyveromyces marxianus UCD (FST) 55–82 was found to be the best producer of ethanol grown in a simple medium at 35°C. The ethanol production was found to be growth‐associated having a μmax = 0.41. h−1 and the ethanol and biomass yields were determined to be Yp/s = 0.45 (88% of the theoretical) and Yx/s = 0.04 with 92% of the original sugars utilized. On the basis of carbohydrate yields of Jerusalem artichoke reported in the literature and these batch kinetic studies with K. maxxianus, the calculated ethanol yields were found to range from 1400 kg ethanol acre −1 yr−1to a maximum of 2700 kg ethanol acre −1 yr−1. The SCP yields for K. marxianus were calculated to range between 130 to 250 kg dry wt cell acre −1 yr−1. The potential for developing an integrated process to produce ethanol and SCP is also discussed.