An improved method to evaluate the o-diphenol oxidase activity of soil

Phenolic compounds are intermediary transformation products of many natural ly occurring substances and synthetic chemicals, including crop residues, o rganic wastes, pesticides and industrial products. They are suitable substr ates for the phenolases and peroxidases produced by the soil microflora. Al though measurement of the enzymatic oxidation of phenolic compounds is an i mportant measure of the soil microflora's capacity to degrade potentially r ecalcitrant organics, the proposed methods to perform this measurement are few and questionable. In this paper a new, reliable and simple method to me asure the o-diphenol oxidase activity in whole soil sample is proposed. The method is based on a spectrophotometric determination of a red compound (4 -(N-proline)-o-benzoquinone) developed from enzymatic oxidation of catechol in the presence of proline. (C) 2000 Elsevier Science Ltd. All rights rese rved.