Ethanol Fermentation of Algae Spirogyra using Saccharomyces cerevisiae by Adding Hydrogen and Nitrogen Gases to the Space Fermentor

Abstract

This study aims to determine the effect of different types of gases (nitrogen and hydrogen), pH, and the fermentation duration to the cell biomass, pH, total reducing sugar, and total ethanol that was produced from the fermentation of algae Spirogyra hyalina hydrolysates using Saccharomyces cerevisiae. Fermentation process carried out in anaerobic conditions. Anaerobic condition is done by using the Hungate technique, namely by passing nitrogen gas or hydrogen gas into the fermenter. Fermentation is done by variation of pH (4, 5, 6) and the variation of fermentation duration (0 hours, 24 hours, 48 hours, 72 hours). The results showed that the highest levels of ethanol achieved by the presence of hydrogen gas at pH 4 with 72 hours of fermentation duration.