- 作者: 蘇遠志; 許清森; 簡金源; 曾楚光
- 作者服務機構: 國立臺灣大學農業化學研究所
- 中文摘要:
由野生黴菌和酵母菌中篩選得到之A.japonicus NTU-1249菌株能產生多量具有果糖轉移活性之β-?喃果糖?
?,可催化庶糖分子進行果糖轉移反應並合成低聚果糖,因而具有工業利用之潛力。本研究藉由培養基之改進及培
養條件之探討,嘗試提高A.japonicus NTU-1249之酵素生產能力,並進行低聚果糖之合成試驗。
使用含有80g/1蔗糖,15g/1大豆粉,5g/1酵母抽出物和5g/1氯化鈉之改良培養基;以及起始pH6.0,通氣量
1.5vvm,攪拌速率500rmp之培養條件,在實驗室小型醱酵槽中培養A.japonicus NTU-1249時,其果糖轉移活性之
產量可高達185.6U/m1,而進一步擴大規模至1,000公升中間工廠醱酵槽培養時,其最高的果糖轉移活性則可達到
256.1U/m1.
使用批式反應器,對50%(w/v)之蔗糖溶液添加5.6U/g sucrose之果糖轉移活性,於pH5.0,50℃下反應24小時,
可順利地進行果糖轉移反應,並合成低聚果糖。反應後得到之糖漿中含有29.8%(w/v)低聚果糖,15.2%(w/v)葡萄糖
和5.0%(w/v)未反應完之蔗糖,此時低聚果糖之產率約為60%。a - 英文摘要: Microbial β-fructofuranosidases with transfructosylating activity can catalyze the transfructosylationof sucrose and synthesize fructooligosaccharides. Aspergillus japonicus NTU-1249 isolated from naturalhabitat was found to produce a significant amount of β-fructofuranosidase with high transfructosylatingactivity and to have the potential for industrial production of fructooligosaccharides. In order to improveit's enzyme productivity, the medium composition and the cultivation conditions for A. japonicas NTU-1249 were studied. A. japonicus NTU-1249 can produce 83.5 units of transfructosylatine activitv per ml broth whencuitivatea in a shaKing flask at 28℃ for 72 hours with a modified medium containing 80 g/1 sucrose, 15 g/1soybean flour, 5 g/1 yeast extract and 5 g/1 NaCl at an initial pH of 6.0. The enzyme productivity was alsooptimized by submerged cultivation in a 5-litre jar fermentor with aeration at 1.5 vvm and agitation at 500rpm. Under these operating conditions, the productivity of transfructosylating activity increased to 185.6U/ml. Furthermore, the transfructosylating activity was improved to 256.1 U/ml in 1,000-litre pilot-scale fermentor. Enzymatic synthesis of fructooligosaccharides by β-fructofuranosidase from A. japonicus NTU-1249was performed in batch type by adding 5.6 units of transfructosylating activity per gram of sucrose to a50% (w/v) sucrose solution at pH 5.0 and 50℃. The yield of fructooligosaccharides was about 60% after reaction for 24 hours, and the syrup produced contained 29.8% (w/v) fructooligosaccharides, 15.2%(w/v) glucose and 5.0% (w/v) sucrose.
- 中文關鍵字: β-fructofuranosidase; transfructosylation; fructooligosaccharides; Aspergillus japonicus NTU-1249.
- 英文關鍵字: --