Abstract: Protein hydrolysate compositions and methods of making the same are disclosed. The protein hydrolysate composition has a protein-rich organic content. The protein hydrolysate composition may be substantially free of exogenous chelating agents, chaotropic agents and surfactants. The protein hydrolysate composition may be low in ash content. The protein hydrolysate composition is produced by processing a biomass, e.g., a microbial biomass, through a combination of physical, chemical and/or enzymatic treatments. The protein hydrolysate may be sourced via microbial biomass from CCk as a carbon source. Also disclosed are methods of using the protein hydrolysate compositions, e.g., as a biostimulant.