以微管陣列薄膜固化酵母菌量產化酒精之可行性研究

No Thumbnail Available

Date

2018

Journal Title

Journal ISSN

Volume Title

Publisher

Abstract

本實驗以新穎的微管陣列薄膜 (microtube array membrane; MTAM) 固化酵母菌進行發酵,發酵過後產物中的乙醇含量則以氣相層析質譜儀進行檢測。微管陣列薄膜是以靜電紡絲技術紡製而成的,這是利用二種不同性質的紡絲液體,在高壓電之下形成雙層結構。其中,親水性的中心核層材料為聚乙二醇(polyethylene oxide; PEO),親油性的外圍殼層則分別使用聚左旋乳酸(poly-L-lactide; PLLA) 及聚碸 (polysulfone; PSF) 來進行實驗。經靜電紡絲製成的薄膜先浸泡在水中,這步驟可以使中心核層的PEO溶於水而達成製得中空纖維的目的。酵母菌使用了Fermentis safale S-04及Kluyveromyces marxianus二種菌種。實驗進行之初,先將酵母菌的個數培養至 107-108 CFU/mL後,再把酵母菌以虹吸原理固化在膜裡面。實驗用每張薄膜的長寬分別為3公分及1公分。以掃描式電子顯微鏡可以觀測到薄膜的單一纖維:直徑約為 50微米,纖維表面的小孔洞為0.5 - 1.5微米。這樣的大小剛好可以關住酵母菌,又可以從微小洞提供養分給酵母菌。為了測試微管陣列薄膜固化酵母菌的效果以及日後量產的可能性,本實驗先應用在自釀啤酒的發酵,並將發酵瓶改為20升的發酵桶。實驗結果發現,本方法比起傳統發酵法效率更高,產能更多。酒精濃度至少提高 15% - 20%。原因是酵母菌固化在薄膜內的反應面積變大,能夠在短時間內充分使用到所有的養份。再者,酵母菌能回收並重複使用,不但可降低發酵時的成本,而且也和符合綠色化學。
In this study, we scaled up fermentation volume from 1 mL to 20 L. Gas chromatography - mass spectrometry was used for the detection of ethanol concentration. A novel technology of using microtube array membranes (MTAM) immobilized yeast cells for mass production of ethanol fermentation. Two types of MTAMs were used to conduct the experiment namely, renewable poly-L-lactic acid (PLLA) and polysulfone (PSF). The MTAMs were cut into a 1 cm (width) x 3 cm (length) size, and the yeasts were siphoned at the desired concentration into the respective MTAMs The presence of nanopores on the ultrathin surface of the MTAM allows for the efficient diffusion of nutrient and waste across the lumen wall. The encapsulated yeast reduced the inhibitory effects, while significantly reducing the cost by repeated use of the encapsulated yeast and the reduction of the need for costly separation. Compared to free cells, MTAM encapsulated yeast registered a better glucose to ethanol conversion efficiency; and in turn registered a higher ethanol concentration of 15% after 10-14 days of fermentation. The successful scaled up fermentation demonstration suggested that potentially, the encapsulation technical using the MTAMs can be applied to various fermentations as a solution to increase output without major modification to existing infrastructures.

Description

Keywords

微管陣列薄膜, 酵母菌固化, 乙醇發酵, microtube array membranes (MTAM), ethanol fermentation, GC/MS, Immobilized yeast cells

Citation

Collections