Ionic Liquid-Based Aqueous Bi-Phasic System and Ultrasound Cell Disruption for Protein Recovery From Spirulina platensis

Abstract

Efficient protein extraction from algal biomass is crucial for sustainable bioresource use, yet traditional methods are often slow and environmentally taxing. This study explores enhanced protein recovery from Spirulina platensis by combining cell disruption techniques with an aqueous two-phase extraction (ATPE) system using ionic liquids (ILs). Ultrasonication, performed at 24 kHz across power densities of 460, 300, and 85 W/cm², was identified as the most effective cell disruption method, significantly improving protein release. Scanning electron microscopy (SEM) provided insights into cell damage patterns that correlate with extraction efficiency. Following disruption, the IL 1-n-butyl-3-methylimidazolium chloride ([Bmim]Cl) was used in the ATPE system, outperforming the traditional PEG/phosphate buffer system in protein separation. Optimizing parameters like pH, solid–liquid ratios, and phase composition further boosted protein partitioning. Tests comparing commercial and synthesized ILs showed slightly higher yields for commercial ILs. This advanced ATPE-IL approach demonstrates high efficiency and sustainability, offering a promising solution for scalable protein extraction in bioresource processing. This study explores fast and efficient methods for extracting soluble proteins from algal biomass, combining bench-scale cell disruption techniques and an ATPE system with ILs. Initially, various cell disruption methods, including ultrasonication at 24 kHz with power densities of 460, 300, and 85 W/cm², were employed to investigate their effects on protein release. The degree of protein extraction was found to be proportional to the extent of cell disintegration, with ultrasonication proving superior. SEM was used to analyze morphological damage from different techniques. The study aims to find the most efficient separation of proteins from S. platensis using an ATPE system with ILs and PEG/phosphate buffer systems. Subsequently, proteins from S. platensis were separated using an aqueous two-phase system (ATPS) with the hydrophilic IL [Bmim]Cl as a solvent. This method's efficiency was compared to traditional PEG/phosphate buffer systems. Key parameters such as pH values, solid–liquid ratios, and phase component concentrations were optimized to enhance protein partitioning efficiency. Comparative analysis between commercial and synthesized ILs showed promising results for ecofriendly bioactive component separations. The integration of these advanced techniques underscores their potential for efficient and sustainable protein extraction from algal biomass.