Ethanol Fermentation on Mixed Sugars Using Mixed Culture of Two Yeast Strains

• Main Authors: Jasman ., Irfan Dwidya Prijambada, Chusnul Hidayat, Donny Widianto
• Format: Article
• Language: English
• Published: Universitas Gadjah Mada, Yogyakarta 2015-11-01
• Series: Indonesian Journal of Biotechnology
• Online Access: http://journal.ugm.ac.id/ijbiotech/article/view/7880

<div>The objective of this study was to evaluate the use of mixed cultures of the recommended yeast strains</div><div>from a previous study on ethanol fermentation using a substrate mixture consisting of sucrose, glucose, and</div><div>fructose. There were three mixed (combination) cultures namely OUT7096/OUT7913, OUT7096/OUT7921,</div><div>and OUT7913/OUT7921. The fermentation medium contained sugar mixture consisting of glucose, fructose,</div><div>and sucrose with a composition generally close to the composition of sugars in sweet sorghum juice. Overall,</div><div>fermentation is carried out in two stages. First fermentation was performed using the three mixed cultures</div><div>to determine the best combination based on the concentration of ethanol produced and the concentration of</div><div>residual sugar. Second fermentation was conducted using the best mixed culture obtained from the fi rst stage.</div><div>This second stage was intended to describe the pattern of the changes in the concentration of ethanol, sugars</div><div>and biomass during the fermentation progresses and to determine some kinetic parameters namely ethanol</div><div>yield (Yp/s), growth yield (Yx/s) and specifi c growth rate (&mu;). The results of the fi rst fermentation showed that</div><div>the best mixed culture was OUT7913/OUT7921 and the subsequent fermentation using this culture provide</div><div>the highest ethanol yield (Yp/s) = 0.47 g.g-1 that was reached at 53rd hour, growth yield (Yx/s) = 0.425 g.g-1, and</div><div>&mu; = 0.12 hour-1.</div><div>Keywords : fermentation, ethanol, mixed culture, mixed sugar</div>