$\underline{Streptomyces}$ sp. HP produced glucose isomerase(EC 5.3.1. 5 D-xylose ketol-isomerase) and the enzyme yield was high when growth in the medium containing xylose or xylan as carbon source.
Xylose was more effective inducer than xylan. By acid hydrolysis of wheat bran, about 70% of xylan in wheat bran was converted to xylose. By using hydrolyzed wheat bran, the optimal composition of medium was determined. After optimization of medium, the enzyme activity of microbial cells grown in hydrolyzed wheat bran medium was increased four times more than that of microbial cells grown in untreated wheat bran medium.
Also some enzymatic properties of soluble enzyme were studied. The enzyme was very stable against heat and had an optimum pH at 8.0. Michaelis - Menten constants of forward and backward reactions were 0.196M and 0.392M respectively.
