고정화 효소를 이용한PFR과 CSTR에서의hexylglucoside의 합성에 관한 연구

Abstract

Beta-glucosidase(BG) from almond (EC 3.2.1.21) shows wide substrate specificity and is used to break beta-glucosidic linkages of conjugated glucosides of disaccharides. Alkylglucosides are surfactants with good biodegradability and low toxicity produced by an enzymatic method. In this paper, highly stable and easily separable immobilized enzyme were developed using nanofibers as enzyme supporting materials. Beta-glucosidase(BG) was immobilized on the surface of the supporting materials with cross-linked enzyme aggregation. The properties of the immobilized enzymes on polyaniline nanofiber (PANI) and magnetically separable polyaniline nanofiber(PAMP) were compared. The storage stabilities of immobilized enzyme were higher than that of free enzyme. After 16days, free-BG, PANI-BG and PAMP-BG showed 32%, 37%, 77% of residual activity at 25℃. The optimal pH and temperature of free and immobilized enzymes were determined for the different reaction conditions. The optimal pH and temperature were 5.0 and 55℃, respectively. Hexylglucoside was synthesized using free-BG and immobilized BG under batch reactor, continuous stirred tank reactor(CSTR) and plug flow reactor(PFR). The conversions of hexylglucoside with free and immobilized enzymes were 6.76% and 4.19% under batch condition and those of free and immobilized enzymes were 6.58% and 14.68 For the different residence times(1, 2 and 4hr), the hexylglucoside conversions were 7.09%, 22.22% and 57.83% respectively. The maximum conversion 57.8% of hexylglucoside was obtained by cotton-PANI-BG at PFR (0.15ml/hr and 4hrs residence time)

Keywords: beta-glucosidase, immobilized enzyme, hexylglucoside, CSTR, PFR.