Mechanical properties of Ca-alginate beads for ethanol fermentation with immobilized yeast

Abstract

There is an increased interest in the area of ethanol fermentation with immobilized cells in the recent years. These immobilized biocatalysts need to possess certain characteristics that meet the specific characteristics of the continuous fermenting processes - high mechanical stability, long time operation, high fermenting activity. In the present work the mechanical characteristics of the Ca-alginate beads before and after the immobilization procedure are investigated. For the specific tasks were investigated preparations obtained from Na-alginate solutions with a concentration of 1%, 2%, 3% and 4%. The mechanical properties of the samples were measured with DMAQ800 rheometer. The investigated samples have a viscous-elastic property. These properties strongly depend on the Na-alginate solution concentration. It was found that the added yeast suspensions leads to significant change in the sample elasticity. The received results could be used in the process of investigation and modeling of ethanol fermentation with immobilized cells.