High gravity ethanol fermentation from sugarcane juice

The changes of sugars(glucose,fructose and sucrose),biomass and ethanol production during the high gravity ethanol fermentation from sugarcane juice by Saccharomyces cerevisiae strain GJ2008 at 32℃ under batch condition in 5L bioreactor were studied.The contents of sugars were detected by HPLC-ELSD,while the ethanol production was determined by gas chromatography(GC).The results showed that the highest glucose consumption rate was 9.46g/(L·h)at 12h,while the highest consumption rates of fructose,sucrose and total sugar were 12.61g/(L·h),12.30g/(L·h) and 20.59g/(L·h),respectively at 14h.At 16h,the highest ethanol production rate was observed as 7.89g/(L·h),and the cell death rate(22.9%) became greater than cell budding rate(12.6%).And then,the yeast cell vitality gradually decreased.At the end of fermentation,ethanol content,residual sugar,sugar utilization percentage and fermentation efficiency were 12.8%vol,22.50g/L,90.9% and 79.69%,respectively.