Enhancing the efficiency of ethanol production from molasses using immobilized commercial Saccharomyces cerevisiae in two layer alginate-chitosan beads

Abstract

Abstract The commercial Saccharomyces cerevisiae has been successfully inoculated and immobilized in the present study. The immobilization was conducted through a double layer encapsulated method in which 3% of alginate and 1% of chitosan become the first and second layer, respectively. The light microscopy confirmed that the inoculated-cell was dispersed and spread well in the alginate layer as the first layer. The interaction between alginate-chitosan was confirmed by Fourier Transform Infra-Red (FTIR), and the results demonstrated the physical interaction without forming any chemical interaction and binding in the immobilized cell. The immobilized cell was then used for producing ethanol from molasses through the batch fermentation process. The immobilized cell can successfully convert the glucose to ethanol and used for three cycles of fermentation before finally being saturated. The saturated was generated by breaking down of the chitosan layer generated by cell proliferation. The layer breakage forms the fouling as the effect of absorbed molasses in the surface of layer. However, the fermentation using immobilization cells provides the high-efficiency process by converting high percentages of ethanol yield production and solve the post-treatment process.