Effective solvents for proteins recovery from microalgae

¹ Department of Chemical and Environmental Engineering, Faculty of Science and Engineering, University of Nottingham Malaysia, Jalan Broga, Semenyih, 43500, Selangor Darul Ehsan, Malaysia.
² School of Energy and Chemical Engineering, Xiamen University Malaysia, Jalan Sunsuria, Bandar Sunsuria, 43900 Sepang, Selangor, Malaysia.
³ Faculty of Applied Sciences, UCSI University, UCSI Heights, 56000 Cheras, Kuala Lumpur, Malaysia.
⁴ Biorefinery and Process Automation Engineering Center, Chemical and Process Engineering, The Sirindhorn International Thai-German Graduate School of Engineering, King Mongkut’s University of Technology North Bangkok, Bangkok, 10800, Thailand

^* Corresponding author: showpauloke@gmail.com
kitwayne.chew@xmu.edu.my
kuanshiong.khoo@hotmail.com

Abstract

From an industrial perspective, the exploitation of microalgae as protein source is of great economical and commercial interest due to several attractive characteristics. However, the protein extraction efficiency is limited by the multiple layers of rigid and thick cell walls that are enriched with recalcitrant structure of cellulose. Therefore, an efficient method of cell disruption is necessary to disintegrate the cell wall and promote the release of protein contents. The conventional methods for downstream processing, e.g. disruption, isolation, extraction, concentration and purification, are energy-intensive and costly because they typically compose of several operational units. To reduce the overall process cost and establish an economical feasible process for the large-scale production of microalgae derived products, a more cost-effective and ecofriendly technique in downstream processing is in critical demand. One of the main challenges for protein extraction from microalgae cells is the recalcitrant structure of microalgae cell wall. This work aims to provide a guideline on the selection of the solvent to facilitate the proteins release during the cell disruption process. The influences of various solvent types (methanol, ethanol, 1-propanol and water) were evaluated and compared based on the protein yields. It was found that water solvent released the highest protein concentration from microalgae compared to the other tested solvents.