Extraction of Proteins from Soil

Soil metaproteomics could explore the proteins involved in life activities and their abundance in the soils to overcome the difficulty in pure cultures of soil microorganisms and the limitations of proteomics of pure cultures. However, the complexity and heterogeneity of soil composition, the low abundance of soil proteins, and the presence of massive interfering substances (including humic compounds) generally lead to an extremely low extraction efficiency of soil proteins. Therefore, the efficient extraction of soil proteins is a prerequisite and bottleneck problem in soil metaproteomics. In this chapter, a soil protein extraction method suitable for most types of soils with low cost and enabling simple operation (about 150 μg protein can be extracted from 5.0 g soil) is described. The quantity and purity of the extracted soil proteins could meet the requirements for further analysis using routine mass spectrometry–based proteomics.