A study of some kinetic properties of glucose isomerase activity produced from a local isolate Streptomyces spp. SH(10)

Abstract

The effect of temperature, pH, concentration of substrate (glucose), and the effect of some metallic ions on glucose isomerase activity was studied. The enzyme was produced by submerged fermentation of Streptomyces roseiscleroticus SH10 isolated from local soils. Maximum enzyme activity was found at pH 7, temperature 60°C and 0.8  mol of glucose as a substrate, and the enzyme remains stable at pH = 7-9 and temperature 30-60°C.

Glucose isomerase was activated by ions (Mg⁺², Ca⁺², Mn⁺², Co⁺²) while another ions (Cu⁺², Ag⁺, Hg⁺²) played an inhibition role. A mixture of cobalt and magnesium ions exhibited highest activation rate.