Innovative Approaches to Bioethanol Production: Utilizing Olive Oil Wastewater, Milk Whey, and Sugarcane Molasses through Enzymatic Hydrolysis and Yeast Immobilization

Abstract

This work describes a new method for fermentative ethanol production by using a triple waste substrate mixture of olive oil wastewater, milk whey, and sugarcane molasses. Enzymatic Hydrolysis was done by a commercial enzyme complex Natuzyme at different concentrations, namely 0.25%, 0.5%, and 0.75%. Then, batch fermentation was carried out by immobilized cells of Saccharomyces cerevisiae (Sc) isolated from olive oil wastewater. The ethanol yields produced by immobilized S. cerevisiae, it was within the range of 16.56 g/L and 34.56 g/L at the highest yield for 0.5% enzyme concentration, which showed an optimal balance between hydrolytic efficiency and yeast activity. Four different formulations were prepared, different in various components of waste, which supplied different substrate compositions with different performances in fermentation outcomes. These results evidence the possibility of valorizing heterogeneous streams of wastes for the sustainable production of ethanol. This study not only furthers environmentally responsible waste management but also opens up a very promising avenue for large-scale ethanol production using cell immobilization techniques.