Abstract:

Compared with spectrophotometry for the determination of xanthine oxidase activity by horseradish peroxidase, a quick and simple solid agar plate method of assaying the activity of xanthine oxidase(XOD) produced by Arthrobacter sp.X11 was developed with xanthine as a substrate. The activity of xanthine oxidase was analyzed quickly and roughly according to the diameters of color haloes. This method was used to optimize nitrogen source in a fermentation medium for enzyme production.

Key words: xanthine oxidase, plate diffusion method, diameter of color halo, nitrogen source