新加坡國立大學楊昆霖教授做客第240期化苑講壇
報告題目：Self-immobilized, Cross-linked Enzyme Aggregates(CLEAs) for Biocatelysis
報 告 人 ：楊昆霖教授
報告時間：2017年3月24日（周五）上午10：30
報告地點：東校區能量轉換與存儲材料化學教育部重點實驗室二樓會議室(韻苑28棟)
報告人簡介：
楊昆霖，1994年畢業于臺灣大學化學工程系，1996年取得碩士學位。于1998年赴美國佐治亞理工學院深造，于2002年取得博士學位。期間，他以優異的成績獲得美國分子設計獎學金，并以電雙層的研究得到美國化學學會最佳博士論文獎。同年，他前往威辛康辛大學麥迪遜校區從事博士后研究，專攻液晶在化學及生物傳感器方面的應用。2005年，他取得新加坡國立大學的助理教授一職，并成立液晶及生物分子實驗室，開啟微流體傳感器的研究方向。2012年榮升副教授并取得終生教職。在新加坡的這段時間，他在液晶傳感器的研究取得重大突破，并且在SCI著名期刊包括Advanced Materials, Advanced Functional Materials, Langmuir 及 Biosensors and Bioelectronics發表多篇論文。此外, 他還是一位受學生歡迎的好老師，在各項教學評測中名列前茅，也是教學獎的常客，最近連續三年他都獲得新加坡國立大學的最佳教學獎，并進入教學名人榜。
報告內容：
Enzymes have many advantages over inorganic catalysts but they are very sensitive to temperature and pH. Recently, we showed that enzymes can be immobilized as cross-linked enzyme aggregate (CLEAs) without using any solid carriers to improve their stability. Firstly, millifluidic reactors with two laminar flows of an enzyme solution and an organic solvent were employed to prepare uniform CLEAs of cellulase and laccase. CLEAs of cellulase had a size between 200 and 400 nm and were highly uniform. They can be collected on silica gels or entrapped in a membrane as practical biocatalysts to hydrolyze cellulose with an activity up to 86% of the free cellulase. Because of their large size, CLEAs can also be encapsulated in calcium alginate beads without any leaching problems. This features allowed CLEAs of cellulase to be reused and recycled up to 10 times for hydrolysis of cellulose. Similarly, CLEAs of laccase were prepared and entrapped in a membrane for oxidization of phenolic compounds. Trypan blue, a dye molecule, can be degraded by using membrane-bound CLEAs continuously for 96 h. Finally, glucose oxidase (GOx) and horseradish peroxidase (HRP) were co-immobilized as combi-CLEAs by using a coaxial-flow millifluidic reactor. The combi-CLEAs were used to catalyze cascade chemical reactions and minimize the decomposition of hydrogen peroxide in the presence of catalase. As a result, the overall reaction rate increased by 14 times compared to free enzyme mixtures in the presence of 6.3 mM of catalase. The combi-CLEAs were further exploited to develop colorimetric glucose assays with a limit of detection of 0.5 mM and a linear range up to 27.8 mM. In the future, millifluidic reactors can be used to prepare CLEAs with tunable sizes and properties for various industrial applications.
