Quantitative soil zymography: Mechanisms, processes of substrate and enzyme diffusion in porous media

Publication date: December 2018Source: Soil Biology and Biochemistry, Volume 127Author(s): Andrey Guber, Alexandra Kravchenko, Bahar S. Razavi, Daniel Uteau, Stephan Peth, Evgenia Blagodatskaya, Yakov KuzyakovAbstractSoil membrane zymography enables 2D mapping of enzyme activities on the surface of soil samples. The method is based on diffusion of components of enzymatically-mediated reactions to/from membrane, and, thus, reflects the distribution of enzyme activities at the intact soil surface. Zymography has been already successfully implemented in numerous soil ecology applications. Here we identify two methodological aspects for further improvement and expansion of the method at micro and macro scales: first, accounting for the area of contact between the soil surface and the zymography membranes and, second, accounting for diffusion effects during the zymography procedure. We tested three methods, namely, laser-scanning, staining with a fluorescent product (e.g. MUF: 4-methylumbelliferone), and X-ray computed micro-tomography, for assessing the area of the soil surface in contact with the membranes. We quantified diffusion of MUF, enzymes and substrate between the substrate-saturated membrane and soil as well as diffusion processes during membrane zymography via HP2 software. Diffusion of the substrate from the membrane and of the MUF-product to the membrane was detected, while there were no clear evidence of enzyme diffusion to/in the membrane. According to the model si...
Source: Soil Biology and Biochemistry - Category: Biology Source Type: research