Extracting protein from microalgae (Tetraselmis chuii) for proteome analysis

Microalgae have high potential as a resource for sustainable and green protein for food or bioactive molecules. Nonetheless, despite the high protein content of microalgae (40 - 70% dry weight) progress in the characterization of their protein composition remains challenging. This is due to the highly variable chemical composition of microalgae strains and factors such as their rigid thick cell wall, polysaccharide content, protein stability, pH. The method described herein was developed to optimize protein extraction for proteome analysis of microalgae (Tetraselmis chuii) biomass. The effects on protein solubility of solvent type (organic, denaturing, and non-denaturing) combined with three customized microalgae disruption methods were investigated. The proteome targeted high quality protein extracts were for hydro-soluble proteins recovered by cell disruption using bead milling coupled to centrifugation (protein yield approximate to 13%). The developed method is inexpensive, efficient (yielding high-quality protein extracts with a low content of interfering compounds) and from an industrial perspective easily scalable and compatible with other applications. To add value to the end product we additionally propose the use of stabilizing agents to maintain protein solubility during refrigerated storage and a method targeting the fractionation of low molecular weight proteins. An inexpensive easy-to-do 5 step protocol for microalgae protein extracts. A protein extraction method free from dangerous or highly polluting chemicals. Production of high yield aqueous protein extracts suitable for proteomics. (C) 2022 The Authors. Published by Elsevier B.V.

Automated summary

This article presents a method for protein extraction from microalgae using bead milling and centrifugation, resulting in high-quality protein extracts. The method is cost-effective, efficient, scalable for industrial applications, and compatible with other processes. In addition, the article proposes the use of stabilizing agents for protein solubility and fractionation of low molecular weight proteins to enhance the value of the end product.