earticle

영어

Recombinant Escherichia coli JM109 containing a DNA fragment encoding a sucrose hosphorylase (splP) cloned from Bifidobacterium longum which is impractical for industrial fermentation due to its obligatory anaerobic nature. The segregational stability of the recombinant vector was maintained over 80% without IPTG. In the presence of IPTG, it dropped to 0% after 80 generations. The structural stability of the recombinant plasmid was maintained stably. The optimal concentration of the inducer was found to be 10 μmol l-1 and cultivation at 37℃ with earlier induction was the best for the overall productivity of the active recombinant enzyme. In a
minimal medium, sucrose was a better carbon source than glucose for the enzyme production. By using the sucrose phosphorylase to transfer glucose from sucrose to caffeic acid, the enzyme reaction was carried out with an aqueous buffer in the supercritical CO2 phase. It was found that a transfer product, caffeic acid-glucoside, was produced in the enzymatic reaction in the supercritical phase. ACKNOWLEDGEMENT This work was supported by the Korea Research Foundation Grant funded by the Korean Government (MOEHRD) (KRF-2005-003-R0610261).