Colloidal gas aphrons: A novel approach to protein recovery

Area of Science:

• Biotechnology
• Separation Science
• Colloid and Surface Chemistry

Background:

• Colloidal gas aphrons (CGAs) are microbubbles stabilized by surfactant layers, generated via high-shear stirring.
• Previous research has not explored CGAs for direct protein recovery.
• Proteins are expected to adsorb onto surfactant bubbles through electrostatic and hydrophobic interactions.

Purpose of the Study:

• To investigate the efficacy of CGAs for recovering proteins from aqueous solutions.
• To evaluate the impact of various process conditions on protein recovery efficiency.
• To assess the maintenance of protein activity post-recovery.

Main Methods:

• Utilized CGAs generated from sodium bis-(2-ethyl hexyl) sulfosuccinate (AOT), an anionic surfactant.
• Employed lysozyme as the model protein for recovery experiments.
• Systematically varied parameters including protein/surfactant concentrations, pH, and ionic strength.

Main Results:

• Achieved successful lysozyme recovery with optimal conditions yielding 95% recovery, a 19-fold enrichment ratio, and a 302-fold separation ratio.
• High recovery and enrichment were generally observed at protein concentrations ≤0.41 mg/mL and surfactant concentrations >0.11 mg/mL.
• Protein activity was maintained throughout the process, even after observed precipitation and resolubilization.

Conclusions:

• CGAs represent a promising technique for efficient protein recovery from aqueous solutions.
• Optimized process conditions are crucial for maximizing recovery and separation efficiency.
• The method demonstrates potential for bioseparation applications while preserving protein functionality.