STUDY ON IMMOBILIZED YEAST CELLS WITH HRDROPHILIC POLYMER CARRIER BY RADIATION - INDUCED COPOLYMERIZATION

In this paper, various kinds of monomers 2-hydroxyethyl methacrylate (HEMA), 2-hydroxyethyl acrylate (HEA), hydroxypropyl methacrylate (HPMA) and methoxy polyethylene glycol methylacrylate (M-23G) were eopolymerized by radiation technique at low temperature (-78℃) and several kinds of copolymer carriers were obtained. Yeast cells were immobilized through adhesion and multiplication of yeast cells themselves on these carriers. The etharol productivity of immobilized yeast cells with these carriers was related to the monomer composition and water content of copolymer carriers and the optimum monomer composition was 20%:10% in poly (HEA-M23G). In this case, the ethanol productivity of immobilized yeast cells was 26 mg /( ml·h), which was 4 times as high as that of free cells. In this study, the effect of adding of crosslinking reagent (4G) in copolymer on activity of yeast cells immobilized with the carriers were also studied. It was found that the effect of adding crosslinking reagent (4G) in lower monomer composition of poly(HEA-M23G) on the ethanol productivity of immobilized cells was better than that in higher one in this work.