Production of fructose and ethanol from media with high sucrose concentrations by a mutant of Saccharomyces cerevisiae

The production of enriched fructose syrups and ethanol from a synthetic med ium with high sucrose concentrations was studied in a batch process using S accharomyces cerevisiae ATCC 36858. The results showed that the fructose yi eld was above 92% of theoretical values in synthetic media with sucrose con centrations between 180 g dm(-3) and 726 g dm(-3). Ethanol yield was about 82% in media with sucrose concentrations up to 451 g dm(-3). A product cont aining 178 g dm(-3) fructose, which represents 97% of the total sugar conte nt, and 79 g dm(-3) ethanol was obtained using a medium with 360 g dm(-3) s ucrose. The fructose fraction in the carbohydrates content in the produced syrups decreased with increases in the initial sucrose concentration. In a medium with initial sucrose concentration of 574g dm(-3) the fructose conte nt in the produced broth was 59% of the total carbohydrates. Glycerol and f ructo-oligosaccharides were also produced in this process. The produced fru cto-oligosaccharides started to be consumed when the concentration of sucro se in the media was less than 30% of its initial value. Complete hydrolysis of these sugars was noticed in media with sucrose concentrations below 451 g dm(-3). These findings will be useful in the production of ethanol and h igh fructose syrups using sucrose-based raw materials with high concentrati ons of this carbohydrate. (C) 2001 Society of Chemical Industry.