Advancements in High Gravity Fermentation Strategies for Optimizing Ethanol Production from Sugarcane-Based Substrates

The need for more efficient ethanol production methods from sugarcane-based substrates has necessitated the study of (very) high-gravity fermentation strategies. High gravity (HG) and very high gravity (VHG) fermentation are fermentation processes that involve fermenting substrates with significantly higher concentrations of sugars or solids than traditional fermentation methods, typically leading to higher ethanol yields and process efficiencies. This review provides a comprehensive overview of recent advancements, challenges, and future prospects in HG and VHG fermentation for ethanol production from sugarcane-based substrates. It was observed that sugarcane juice, molasses, and bagasse have been used for the production of ethanol. It was also observed from various studies that the use of tailored yeast strains, coupled with optimized process conditions such as fermentation temperature, residence time, pH, substrate concentration, aeration, additional supplements, and the presence of inhibitors, has yielded remarkable improvements in the fermentation efficiency of sugarcane-based substrates and ethanol yields. Additionally, challenges in implementing HG and VHG fermentation of sugarcane-based substrates, as well as recommendations for further research and development, are presented. This study’s significance cannot be overstated, as it has the potential to advance biofuel technology by optimizing ethanol yields from sugarcane, thereby promoting sustainable energy solutions.