The establishment of a marine focused biorefinery for bioethanol production using seawater and a novel marine yeast strain

Zaky, Abdelrahman Saleh; Greetham, Darren; Tucker, Gregory A.; Du, Chenyu

Abstract

Current technologies for bioethanol production rely on the use of freshwater for preparing the fermentation media and use yeasts of a terrestrial origin. Life cycle assessment has suggested that between 1,388 to 9,812 litres of freshwater are consumed for every litre of bioethanol produced. Hence, bioethanol is considered a product with a high-water footprint. This paper investigated the use of seawater-based media and a novel marine yeast strain ‘Saccharomyces cerevisiae AZ65’ to reduce the water footprint of bioethanol. Results revealed that S. cerevisiae AZ65 had a significantly higher osmotic tolerance when compared with the terrestrial reference strain. Using 15-L bioreactors, S. cerevisiae AZ65 produced 93.50 g/L ethanol with a yield of 83.33% (of the theoretical yield) and a maximum productivity of 2.49 g/L/h when using seawater-YPD media. This approach was successfully applied using an industrial fermentation substrate (sugarcane molasses). S. cerevisiae AZ65 produced 52.23 g/L ethanol using molasses media prepared in seawater with a yield of 73.80% (of the theoretical yield) and a maximum productivity of 1.43 g/L/h. These results demonstrated that seawater can substitute freshwater for bioethanol production without compromising production efficiency. Results also revealed that marine yeast is a potential candidate for use in the bioethanol industry especially when using seawater or high salt based fermentation media.

Citation

Zaky, A. S., Greetham, D., Tucker, G. A., & Du, C. (2018). The establishment of a marine focused biorefinery for bioethanol production using seawater and a novel marine yeast strain. Scientific Reports, 8(1), https://doi.org/10.1038/s41598-018-30660-x

• Journal Article Type: Article
• Acceptance Date: Jul 26, 2018
• Online Publication Date: Aug 14, 2018
• Publication Date: 2018-12
• Deposit Date: Nov 6, 2018
• Publicly Available Date: Nov 6, 2018
• Journal: Scientific Reports
• Print ISSN: 2045-2322
• Electronic ISSN: 2045-2322
• Publisher: Nature Publishing Group
• Peer Reviewed: Peer Reviewed
• Volume: 8
• Issue: 1
• Article Number: 12127
• DOI: https://doi.org/10.1038/s41598-018-30660-x
• Public URL: https://nottingham-repository.worktribe.com/output/1230341
• Publisher URL: https://www.nature.com/articles/s41598-018-30660-x