ISO/CD TS 25672

Soil quality — Determination of phenol oxidase (laccase) activity in soil using micro-well plates

Scope

This document specifies a method for determining the laccase activity in soil samples using 2,2-azino-bis-(-3-ethylbenzothiazoline-6-sulfonic acid) (ABTS).
Enzyme activities of soil vary seasonally and depend on soil chemical, physical and biological characteristics. This method can be applied either to determine the natural activity level in different soils, to detect harmful effects on soil enzyme activities derived from anthropogenic activities, or to test chemicals.
This method was not developed for determining the laccase activity in soils showing reducing properties (e.g. waterlogged soils). An adaptation of the method may be necessary to measure the enzyme activity in upper layers (OL, OF, OH horizons) of forest floor humus forms with low microbial activity or interfering compounds (e.g. moder or raw humus). This includes determining the appropriate sample pre-treatment (e.g. milling and/or sieving to 2 mm or 5 mm suitable?), sample weighing and controls