Thermostable glucose isomerase from psychrotolerant Streptomyces species (original) (raw)

2007, International Journal of …

Glucose isomerase (EC 5.3.1.5) was extracted from Streptomyces spp., isolated from Mt. Everest soil sample, and purified by ammonium sulfate fractionation and Sepharose-4B chromatography. A 7.1 fold increase in specific activity of the purified enzyme over crude was observed. Using glucose as substrate, the Michaelis constant (K M ) and maximal velocity (V max ) were found to be 0.45M and 0.18U/mg. respectively. The optimum substrate (glucose) concentration, optimum enzyme concentration, optimum pH, optimum temperature, and optimum reaction time were 0.6M, 62.14μg/100μl, 6.9, 70ºC, and 30 minutes, respectively. Optimum concentrations of Mg 2+ and Co 2+ were 5mM and 0.5mM, respectively. The enzyme was thermostable with half-life 30 minutes at 100ºC. Dhungel B, Subedi M, Tiwari KB, Shrestha UT, Pokhrel S and Agrawal VP (2007)Thermostable glucose isomerase from psychrotolerant Streptomyces species. Int J Life Sci 1 : 6-10