2013 年 46 巻 4 号 p. 302-306
Glucose oxidase (GO) is encapsulated in phosphatidylcholine vesicles (PC liposomes) for controlling the oxidation rate of glucose at 40°C. The liposome membrane is composed of DEPC (1,2-dierucoyl-sn-glycero-3-phosphocholine), POPC (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine) or DLPC (1,2-dilauroyl-sn-glycero-3-phosphocholine). These lipids are different in the length and degree of unsaturation of acyl chains. In the static liquid system, the permeation of glucose through the membrane controls the oxidation rate. The GO in the DEPC liposome shows the highest activity, while that in the POPC liposome exhibit significantly low activity. In an external loop airlift bubble column, the oxidation reaction in the DEPC liposome system is markedly accelerated because of gas–liquid flow-induced membrane permeabilization to glucose. On the other hand, the oxidation rate obtained with the POPC liposome is still strongly controlled by the membrane permeation process and the rate is dependent on the superficial gas velocity in the airlift. The above results clearly demonstrate that the rate of liposomal GO reaction is controllable on the basis of the properties of acyl chains of lipids in combination with the gas-liquid flow of the liposome suspension.
