Production of fructose by enzymatic process

Abstract

Two strains S-P-1 and S-P-2, both Streptomyces Sp., were found to have relatively high specific enzyme activity compared to that of organisms reported by others. The specific activity of the enzymes produced from these two strains were 0.25 and 0.198 international units respectively. Glucose isomerase from S-P-1 strain was found to be stable under the temperature of heat treatment (at 65$^\circ$C) for fixation of enzyme inside the Cell. In addition, it was found that this enzyme needed no toxic metallic ion for enzyme activity and xylan could replace xylose as an inducer. Main drawback of this enzyme is that this enzyme had a relatively lower conversion(42.7\% fructose) compared to other enzymes, and it had a lower specific activity when xylan was used as an inducer in place of xylose by a factor of 1/15. Optimal temperature and $p^H$ of enzymatic reaction was at 85$^\circ$C and 7.5 respectively. Reaction kinetics of whole-cell-enzyme was studied and kinetic parameters were determened for the purpose of using these data for operation and designing of enzyme reactor system. The reaction mechanism was found to follow the single substrate reversible reaction kinetics. The kinetic constants determened experimentally are: Kmf = 0.33M, Kmb = 1.0M, Vmf = 0.88 $\mu$ mole per min., Vmb = 2.96 $\mu$ mole per min. and Keq = 0.74.