由於石油蘊藏量有限，且國際原油價格不斷上漲，研究開發替代能源的重要性日益彰顯，在眾多替代能源中，生質酒精頗受全球矚目。生質酒精是指由生物物質所製成之酒精，生質酒精與汽油混合之燃料即為生質酒精汽油，為可再生燃料，發展生質酒精汽油使用自產能源可創造就業機會、增加能源來源多元化，同時減少溫室氣體排放。 本篇論文的主要目的是在探討「光」這個環境因子對於S. cerevisiae生產酒精之影響。主要探討的有白光、紅光、藍光三種不同光源在不同光強度下對Saccharomyces cerevisiae在菌體生長及產物生產上所造成的效應，再利用兩階段照光實驗同時提升菌體及產物的產量，實驗結果發現不同光源都有其最適光照強度，超過了最適光照強度則會對Saccharomyces cerevisiae產生抑制的現象，其中白光及紅光為600 Lux、藍光為900 Lux，不同光源對Saccharomyces cerevisiae也有不同生理效應產生:紅光會促進菌體的生長、藍光會促使酵母菌將基質轉化成酒精、白光則是同時促進菌體及酒精的產量，最後藉由兩階段照光實驗調控出最佳製程，其酒精產量為92.5 g/l為避光時的1.3倍，比生長速率也提升2.1倍，而productivity則提升了1.9倍之多。 整體而言，照光對Saccharomyces cerevisiae是有正面的幫助，且不同波長的光源的確會對Saccharomyces cerevisiae有不同的效應。 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).
