Researchers at The Novo Nordisk Foundation Center for Biosustainability (DTU Biosustain) have developed a new method for monitoring contamination in bioethanol production that has the potential of boosting industry revenue by over $1.6 billion USD, while also cutting CO2 emissions by 2 million tons.
Contaminant bacteria present in the raw material used for bioethanol production can significantly affect the efficiency of the required fermentation process. Current methods of characterizing these contaminant microbes do not fully capture their diversity or impact. The team investigated the contaminant population from the sugarcane bioethanol production process at strain-level resolution, where they found that the interplay between different species significantly impacts ethanol yield.
“Our research provides a comprehensive analysis of microbial populations across all stages of the industrial bioethanol process in two major Brazilian biorefineries. By using a combination of shotgun metagenomics and cultivation-based methods, we identified ecological factors that influence community dynamics and bioconversion efficiency,” said Postdoc Felipe Lino from DTU Biosustain. “The study demonstrates that specific bacterial strains, influenced by temperature, can either hinder or enhance ethanol yield. This improvement could only be achieved with the advanced techniques we utilized.”
The results of the study could lead to the development of new microbial and process control solutions that could control undesirable microbes and enhance the efficiency of bioethanol production. This would lead to more cost-effective biofuels, increased efficiency, and a substantial reduction in CO2 emissions. While particularly relevant for the biofuel and industrial biotechnology industries, research groups focused on bioinformatics tools for analyzing microbiomes at strain-level resolution could also find this of value.
“We have mapped the microbial populations at strain-level resolution to uncover the true impact of non-yeast microbes on fermentation performance. We identified specific strains of the L. fermentum species causing the most damage to the process, while other strains are neutral and should even be kept as a buffer against harmful ones. Increased temperatures were linked to the growth of specific L. fermentum strains that negatively affect yeast viability and fermentation efficiency. This underscores the importance of adopting higher resolution methods in the future to monitor microbial communities,” stated Professor Morten Sommer from DTU Biosustain.