High montmorillonite content may affect soil microbial proteomic analysis

We studied the effects of high montmorillonite content in soil on the proteomic analysis of Cupriavidus
metallidurans CH34 inoculated into model soils, containing a montmorilonite gradient. Bacterial
proteomic analysis was conducted by two-dimensional gel electrophoresis (2-DE) coupled to mass spectrometry.
The results showed that increasing the montmorillonite content in artificial soil the bacterial
viability did not affect but the amount of extracted proteins and the number of protein spots in 2-DE
decreased. Higher soil montmorillonite content also affected the protein identification, likely due to
montomrillonite-induced conformational changes in proteins or degradation. Therefore the development
of soil proteomics needs to increase the studies of interaction between protein and soil components as
clays or humic substances. This experiment showed how the use of a model study can be an help to
achieve more information about the complexity of soil and the fate of proteins in soil.