Soil enzymes are preferentially associated with larger particles in highly organic Arctic tundra soils (enzyme activity)

In the soil cores, our results showed activity was present for most of the hydrolytic enzymes and there were clear differences among the particle size and disruption treatments. In the sonication + blending treatment, five of six hydrolytic enzymes showed higher activity compared to blending only (standard treatment) or sonication only, suggesting that enzymes are bound to larger particles of the soil as opposed to smaller such as clays and tannins. Furthermore, higher activities in unfiltered and 50 µm (micrometer) filters relative to much finer 2 µm filters suggested that the enzymes were preferentially bound to larger particles in the soil, meaning that enzymes are not equally distributed across the soil matrix. These results suggest that the enzymes are likely bound to the larger organic substrates they are decomposing, potentially preventing their transport away from the microbes that produce them.