| 摘要: | 摘要
隨著現代發酵工業的進步，衣康酸發酵產品應用已逐步擴展到各類民用和工業產品，此外，美國能源局也指出請衣康酸為十二種重要生物化學品之一，其未來具有相當大的潛在優勢。衣康酸，也稱為亞甲基琥珀酸，是一種白色結晶天然存在的有機化合物，它是無毒、並易於生物降解的。可以應用在製造塑料，合成樹脂，塗料，紙，藥品，農藥，絲綢等領域。
過去，台灣曾是以農業立國，其中水稻為最重要的農作物，每當水稻收割後，留下的是許多稻稈、稻殼等農業廢棄物，長期以來農業廢棄物都是透過焚燒、掩埋的方式處理，造成許多空氣汙染及環境問題，從發酵原料的考量下，如果可以利用農業廢棄物作為碳源並用於衣康酸生產，將可以大大提升衣康酸的經濟價值，也可以解決農業廢棄物的後續處理問題。
在本實驗中，我們試圖優化稻稈酸水解處理流程，結果表明，在1211％硫酸、固液比10%、水解60分鐘為最佳水解條件。在此操作下，可得還原糖（27.14克/升），醋酸（0.5克/升），糠醛（0.1克/升），羥甲基糠醛（0.013克/升），另外針對抑制物的去除，活性炭和PDMS海綿被用於去毒處理，其中在活性炭處理下，乙酸、糠醛、HMF可除去約30％、98％、90％;然而PDMS海綿處理下，糠醛，HMF可除去約50％。除了去毒化處理，我們也研究抑製物對於發酵的影響。令人驚訝的是，結果表明，在低濃度醋酸存在下，適度的提升pH值能夠促進菌體生長及衣康酸的生產。
;With the advances in modern fermentation industry, its application has been gradually extended to all kinds of domestic and industrial products. Fermentation products of itaconic acid has become popular in recent years. Moreover, the US department of energy has enlisted itaconic acid as one of the twelve kinds of important biochemicals with potential advantages in the future. Itaconic acid, also known as methylenesuccinic acid, is a white crystalline naturally occurring organic compound. It is non-toxic, and readily biodegradable. It can be used in making plastics, synthetic resin, paint, paper, pharmaceutical, pesticide, silk and other applications.
In the past, air pollution related environmental problems have been reported by agricultural waste treatment. Hydrolysis of rice straw leads to the conversion of cellulose and hemicellulose, the common constituents into monosaccharides. These monosaccharides can be used as carbon source for fermentation of itaconic acid. The method does not only promote the economic production of itaconic acid but also solve the problem of the subsequent processing of agricultural waste. Previous studies have indicated that acid hydrolysis method is rapid and economic for destruction of lignin sheath and exposing the celluose and hemicellulose to hydroylsis. However, during the dilute acid treatment, different inhibitors are also produced. Among them, acetic acid, furfural, HMF have deleterious effect on the fermentation process.
In this research, we have tried to optimize rice straw pretreatment with dilute acid hydrolysis. Results suggested that 1% (v/v) H2SO4, dilute acid treatment at 1.2 atm pressure and 121oc for 60 min is optimal. In this mode of operation, reducing sugars (27.14 g/L), acetic acid (0.5 g/L), furfural (0.1 g/L), HMF (0.013 g/L) were obtained. We have also focused on the effective removal of the inhibitors. Activated charcoal and PDMS sponge were employed for this process. Acetic acid, furfural, HMF can be removed about 30%, 98%, 90% with activated charcoal. However, furfural, HMF can be removed about 50% with PDMS sponge. Before removing the inhibitors, we have also studied the effects of inhibitors for fermentation. Surprisingly, the results indicated that acetic acid can promote the production of itaconic acid at a concentration less than 0.625g/L with increasing pH. |
