Bioethanol production from sugar beet thick juice by Saccharomyces cerevisiae immobilized in alginate-maize stem ground tissue beads

Ethanol produced by alcoholic fermentation from renewable sources, referred to as bioethanol, is widely used as an environmentally friendly and renewable energy source, as well as a chemical in various industries such as the medical, food and feed, pharmaceutical and chemical industries. This paper investigates the bioethanol production from sugar beet thick juice by immobilized Saccharomyces cerevisiae cells in calcium alginate beads and in a new matrix in the form of combined alginate-maize stem ground tissue beads. Higher values of fermentation parameters were obtained by yeast immobilized in new calcium alginatemaize stem ground tissue beads in comparison to calcium-alginate beads. A maximum ethanol concentration of 97.2 g/l, an ethanol yield per utilized sugar of 0.494 g/g, a percentage of the theoretical ethanol yield of 96.6 %, and a volumetric ethanol productivity of 2.03 g/lh were obtained at the end of batch alcoholic fermentation of the medium based on sugar beet thick juice with an initial sugar concentration of 200 g/l.