Simultaneous saccharification and ethanol fermentation by co-culture in biofilm reactors

Bioethanol is one of the renewable energy sources that is highly on demand due to increasing environmental concerns. In this study, ethanol production from industrial potato waste was studied for an improved production of ethanol by employing co-cultures of Aspergillus Niger and Saccharomyces cerevisiae in biofilm reactors. Biofilm is a natural cell immobilization that is used to reduce the cost and improve the effectiveness of the fermentation process. Plastic composite supports (PCS) are solid supports that are used to stimulate biofilm formation in bioreactor during microbial production. The PCS, which was composed of polypropylene, soybean hull, soybean flour, yeast extract, and salts were selected based on the biofilm formation. Growth conditions, pH, temperature, and aeration, were optimized using a three-factor Box-Behnken design of response surface method. Optimum conditions were found to be 35 °C, pH 5.8 with no aeration (0 vvm). This study showed that ethanol production can be produced from industrial wastes by simultaneous saccharification and fermentation with application of biofilm reactors.