The use of poly(ethylene oxide) hydrogels as immobilization matrices for yeast cells

Abstract

Hydrogels based on high molecular weight poly(ethylene oxide) (PEO) copolymers of ethylene oxide and propylene oxide, PEO/alginate and PEO/chitosan were synthesized by UV crosslinking of polymer aqueous solutions. These hydrogels were then characterized in terms of their gel fraction yield, degree of equilibrium swelling, shear storage and loss moduli. The physico-mechanical properties of the hydrogels were then correlated to their ability to sustain the viability and the activity of immobilized cells. The production of ethanol by immobilized Saccharomyces cerevisiae was used to test the suitability of the PEO based hydrogels as immobilization matrices. The PEO hydrogel with a value of 255 Pa for Gʹ and 11 Pa for Gʹʹ, showed the best mechanical properties of all the gels tested. Scanning electron microscope (SEM) analysis of the imobilized S. cerevisiae showed proliferation of the yeast cells entrapped inside the polymeric matrix.

Keywords

• hydrogels
• poly(ethylene oxide)
• immobilization
• entrapment
• saccharomyces cerevisiae