Microbial ecology applied to fuel ethanol production from sugarcane

• Grant number: 25/03048-1
• Support Opportunities: Scholarships abroad - Research
• Start date: January 01, 2026
• End date: December 31, 2026
• Field of knowledge: Engineering - Chemical Engineering - Chemical Process Industries
• Principal Investigator: Andreas Karoly Gombert
• Grantee: Andreas Karoly Gombert
• Host Investigator: Kevin Foster
• Host Institution: Faculdade de Engenharia de Alimentos (FEA). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Institution abroad: University of Oxford, England

Abstract

Due to climate change, a major current goal is to transition from non-renewable to renewable energy sources. Among the current options, fuel ethanol (or bioethanol) stands out as a liquid fuel that can be used to propel light vehicles, either as a standalone fuel or mixed with gasoline. Brazil has led the way globally in producing bioethanol since the 1970s, mainly from sugarcane feedstocks, contributing to the establishment of one of the cleanest energy matrices (~50% renewable), among the biggest economies in the world. There are now ~350 productive biorefineries, which generate bioethanol but they all suffer from a key problem: microbial contamination which inhibits fermentation and reduces yield. In particular, lactic acid bacteria (LAB) co-inhabit the fermentation environment with the yeast Saccharomyces cerevisiae, which converts sugarcane sugars into ethanol. Some of these bacteria appear to help the yeast to grow, but others are harmful and inhibit the yeast and thereby also ethanol production. These harmful bacteria have led to widespread use of antibacterial chemicals, including antimicrobials, antifoaming agents and dispersants. However, these decrease the environmental and economical sustainability of the process and kill the good bacteria along with the bad. We need a new approach. The aim of this project is to use microbial ecology to understand the bacterial impacts on yeast and use this to design probiotic bacterial consortia that promote rather than inhibit alcohol production. By using reduced, synthetic communities, we will unravel the ecological interactions among the microbial strains in the fermentation process, and identify community compositions that are stable and do not compromise ethanol yield. We aim to usher in a new paradigm for bioethanol production in which producers inoculate selected yeast and bacterial strains to maintain a stable and high yield process. In addition to reducing the reliance on chemical treatments, our approaches have the potential to provide enormous economic and environmental gains, due to the large volumes of ethanol produced every year.