Optimization of protein extraction methods for root-associated microbes in maize

The goal of this study was to optimize protein extraction methods to study root-associated bacteria in maize. For this we inoculated sterile maize plants with a synthetic community composed of seven different bacteria (Ben Niu et al. PNAS 2017, vol 114, n 12). Then, we extracted proteins from maize roots using eight different protein extraction methods in triplicates. These methods were a combination of different extraction buffers (SDS or Triton-based) and mechanical disruption methods (bead-beating, N2 grinding, glass homogenizer and freeze-thaw cycles). We found that vortexing maize roots with glass beads in PBS yielded the highest numbers of microbial protein identification.