| dc.description.abstract | The depletion of fossil fuel reserves, the unstable petrol prices and increasing environmental and political pressures has increased industrial foucs toward alternative fuel sources, in many alternative energy source, bio-ethanol was an attentively energy source in world-wide. Bio-ethanol can be blended with gasoline namely ethanol fuel, develop bio-ethanol could increase energy source, reduce exhaust green-house gases.
This research was to confer the light factor on ethanol production by Saccharomyces cerevisiae. This research was use three different wavelength light : White light, Red light, Blue light in different light intensity affected S. cerevisiae on biomass and ethanol production. We found different wavelength light has different optimal light intensity, white light and red light was 600 Lux, blue light was 900 Lux, and if the light intensity excess optimal light intensity, S. cerevisiae was inhibited. This research also found different wavelength has different physiological effect: Red light stimulated S. cerevisiae biomass production, Blue light stimulated S. cerevisiae specific ethanol yield, White light stimulated both biomass production and specific ethanol yield. This research use two-stage process to make optimal fermentation condition. Use two-stage process could make ethanol concentration reach 92.5 g/l, specific growth rate reach 2.1 fold (contrast with dark), ethanol productivity reach 1.9 fold (contrast with dark). | en_US |