苯乙醇具有玫瑰香氣而廣泛用於各種食用香精和化妝品中,全球每年大約生產約10000噸的苯乙醇,其中大部分的苯乙醇都是利用化學方式所合成,但化學法對於環境和健康有很大的危害,因此美國和歐盟對於化學合成的苯乙醇應用在化妝品和食品添加上有嚴格的使用限制,因此如何透過較低的成本和對保護環境的原則下去取代以往化學法所合成的苯乙醇成為了工業發展的趨勢,像是利用微生物發酵的生成則成為一個替代性的平台。 一些研究指出,酵母菌在發酵過程中,可以透過苯丙胺酸生物轉化生成苯乙醇,然而發酵過程中,面臨最大的挑戰為產物的抑制效應,隨著產物苯乙醇和副產物乙醇在發酵過程中累積濃度的增加,會降低生物轉化率導致產物苯乙醇產率的減少和對細胞造成毒性的影響。 本研究設計一個生物反應器-Polydimethylsiloxane (PDMS)海綿連續式萃取發酵系統,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,透過 in situ product removal技術,可以減輕副產物乙醇和產物苯乙醇對菌體之毒性,從而提高主要產物苯乙醇濃度,產量及生產率。
;2-phenylethanol is widely used in the cosmetics and perfumery for fragrance modification with rose-like fragrance. Every year about 10000 tons of 2-phenylethanol are produced worldwide, the most of which through chemical synthesis. The chemical synthesis of 2-phenylethanol can be done by Friedel-Craft reaction. Though inexpensive, these processes are disadvantaged by low selectivity for the desired product and accompanied by the formation of toxic by-products. This makes the chemical production of 2-phenylethanol detrimental to the environment and health. Therefore, legislations of the US and EU have restricted the use of chemical 2-phenylethanol in cosmetics and food products. Therefore, how to replace the 2-phenylethanol by the chemical synthesized has become the trend of industrial development through the lower cost and the principle of protecting the environment, such as the use of microbial fermentation is becoming an alternative platform. Yeast fermentation has become the focal point of research effort utilizing the Ehrlich pathway wherein the L-phenylalanine is converted to 2-phenylethanol. However, 2-phenylethanol and ethanol have common inhibitory effect for yeast fermentation. Many studies had proved that product can be removed through in situ product removal techniques and the yield of product will increase. In this study, owing to the sponges have the hydrophobic property, it can adsorb 2-phenylethanol. So, we use the PDMS sponges to remove 2-phenylethanol, in order to reduce the inhibitory effect. By using the PDMS sponges, the yield of product can be increased and the extracted energy cost can be reduced.