全球暖化已經成為目前地球所面臨的最大問題，其中佔很大一部分的原因為石化燃料的大量使用，導致溫室氣體的排放量不斷上升。為了降低人類對於石化燃料的使用率，興起研究可再生的生質燃料。生質燃料中最主要的就是利用酵母菌發酵生產的生質乙醇。 近年來，燃料乙醇用來取代汽油的使用已越來越被重視與廣泛使用。但過去研究指出，S. cerevisiae發酵生產乙醇時，乙醇體積在發酵液中達到¬4 vol %至10 vol%，乙醇就會反過來對菌體生長產生抑制，導致S. cerevisiae無法生產乙醇，甚至死亡。本篇研究所使用的Saccharomyces cerevisiae BCRC 21812之乙醇耐受性為8.87 vol%。 本研究設計一個新的生物反應器－Polydimethylsiloxane (PDMS)海綿連續式萃取發酵系統(continuous extractive fermentation system by PDMS sponge)。PDMS海綿在此處為萃取劑的角色，利用擠壓海綿進行吸附脫附的過程，將發酵液中乙醇濃度降低，避免tolerance發生，進而提升產率及乙醇濃度。PDMS海綿連續式萃取發酵系統可移除水溶液中50%以上的乙醇量。發酵液經過連續十次的萃取，相較於批次系統可提升21.07%的總乙醇量。;Global warming has become the biggest problem currently facing the earth, which accounted for a large part of the reason for the extensive use of fossil fuels. In order to reduce the use of fossil fuels, and began to study other alternative sources of energy, so the rise of renewable biofuels. Biofuel is one of the main use of yeast fermentation production of ethanol. In recent years, the fuel ethanol replaces gasoline that has been extensively used and attention. Yeast strains of Saccharomyces cerevisiae have been extensively studied for bio-ethanol. Previous studies have indicated that the S. cerevisiae fermentation to produce ethanol, the volume of ethanol in the fermentation broth reached 4 vol% to 10 vol%, ethanol will in turn on cell growth inhibition, leading to S. cerevisiae was unable to produce ethanol, and even death. Saccharomyces cerevisiae BCRC 21812 of ethanol tolerance was 8.87 vol% in this study. In order to avoid the occurrence of tolerance, a novel bioreactor has been developed, continuous extractive fermentation system by polydimethylsiloxane (PDMS) sponge. PDMS sponge is extracting agent, and the adsorption and desorption of ethanol is extruded by sponge. This system can remove more than 50% of ethanol in ethanol solution. After ten successive extraction, the medium was increased the total amount of ethanol by 21.07% compared to batch.
