Ethanol fermentation from Jerusalem artichoke powder using Saccharomyces cerevisiae KCCM50549 without pretreatment for inulin hydrolysis

Abstract

A strain of Saccharomyces cerevisiae, KCCM50549, was found to efficiently ferment the inulin-containing carbohydrates in Jerusalem artichoke without acidic or enzymatic pretreatment prior to fermentation. S. cerevisiae KCCM50549 could utilize almost completely the fructo-oligosaccharides present in Jerusalem artichoke (up to degree of polymerization (DP) of 15), in contrast to the other S. cerevisiae strain such as NCYC625 that fermented the fructo-oligosaccharides with DP of up to around six. Inulin-fermenting S. cerevisiae KCCM50549 produced c.a. 1.6 times more ethanol from Jerusalem artichoke compared with S. cerevisiae NCYC625. Direct ethanol fermentation of Jerusalem artichoke flour at 180. g/L without any supplements or pretreatments by S. cerevisiae KCCM50549 in a 5. L jar fermentor yielded 36.2. g/L of ethanol within 36. h. The conversion efficiency of inulin-type sugars to ethanol was 70% of the theoretical ethanol yield.