Yeast-based solutions for sustainable Aviation Fuels

Project Information

YAF

Grant agreement ID: 101120389

DOI

10.3030/101120389

EC signature date 14 July 2023

Start date 1 December 2023

End date 30 November 2027

Funded under

• Marie Skłodowska-Curie Actions (MSCA)

Total cost

No data

EU contribution

€ 2 637 583,20

Coordinated by

Fundacion IMDEA Energia
Spain

Periodic Reporting for period 1 - YAF (Yeast-based solutions for sustainable Aviation Fuels)

Reporting period: 2023-12-01 to 2025-11-30

Summary of the context and overall objectives of the project

Aviation is one of the most challenging transport sectors to decarbonise due to its reliance on high-energy-density liquid fuels and the absence of viable large-scale alternatives in the near future. Drop-in sustainable aviation fuels (SAF) represent a short- to medium-term solution, as they are fully compatible with existing aircraft engines and fuel infrastructure. However, their large-scale deployment is currently limited by high production costs and feedstock availability.

YAF aims to train 12 doctoral candidates with cutting-edge scientific and transferable skills while advancing biotechnological pathways for SAF production. The project focuses on the use of non-conventional yeasts (NCY) as robust and versatile cell factories capable of converting biowaste-derived carbon sources into valuable SAF intermediates, such as fatty acids, monoterpenes, and sesquiterpenes.

YAF brings together leading academic experts in genetics, systems biology, fermentation, and catalysis, alongside industrial partners covering the entire SAF value chain, from biowaste processing to fuel upgrading and end use. This integrated approach is expected to accelerate technological development and facilitate market uptake.

The project contributes to waste valorisation, greenhouse gas (GHG) emission reduction, and the development of a skilled workforce prepared to tackle future challenges in sustainable energy. YAF aims not only to deliver scientific and technological impact but also to strengthen Europe’s leadership in sustainable aviation fuels and clean energy innovation.

Overall, YAF targets 5 main research and innovation objectives: 1) Maximizing conversion of biowastes into fermentable carbon sources. 2) Development of new NCY cell factories for SAF production. 3) Development of full-advanced catalysts for the production of yeast-derived SAF. 4) Evaluation of the complete supply chain of the proposed technology and demonstrate the environmental, social and techno-economic impacts of the new SAF. 5) Design and implement new SAF solutions that will aim at improving the welfare and wellbeing of individuals and communities.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

Significant progress has been achieved across all the objectives by the performance of several scientific activities, demonstrating the technical feasibility and sustainability potential of yeast-based pathways for SAF production.

Multiple biowaste streams—including agro-food residues, urban pruning waste, textile waste, and algal biomass—have been successfully processed into fermentable carbon sources. Sugar-rich media obtained from these biowastes proved suitable for the cultivation of NCY, while preliminary strategies were developed to convert challenging feedstocks, into short-chain fatty acid (SCFA)-rich media.

Substantial advances have been made in the development of NCY for SAF intermediate production. Key achievements include the establishment of advanced synthetic biology tools (e.g. CRISPRi/a multiplexing), adaptive laboratory evolution to enhance strain robustness, metabolic engineering of terpene pathways, and the optimisation of fermentation processes under industrially relevant and high-salinity conditions. These NCY platforms have been further validated at larger scales, with successful bioreactor fermentations and downstream recovery of triacylglycerols using different cell disruption and extraction strategies.

Advanced catalytic systems based on Ni, Ru, Mo, and W supported on zeolites have been developed and evaluated for the hydroconversion of yeast-derived fatty acids into SAF precursors. Complete experimental and analytical workflows have been established, and hydrocracking tests generated key performance data, enabling the assessment of process efficiency and integration at industrial scale.

Experimental data generated across have provided the basis for environmental, social, and techno-economic assessments. In addition, a comprehensive literature review identified key challenges related to industrialisation, scalability, and sustainability, supporting the development of realistic and data-driven process models.

Finally, the broader societal and environmental implications of the proposed technologies have started to be addressed. The valorisation of biowaste streams and the development of efficient yeast-based SAF production routes contribute to GHG emission reduction, circular economy principles, and reduced dependence on fossil fuels. Preliminary work on communication frameworks and social acceptance highlights the potential of these solutions to improve societal wellbeing while supporting cleaner energy systems.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

Since the start of the project, significant progress has been made across the planned activities, laying a solid foundation for the impacts envisaged. The work carried out to date has advanced the project’s scientific objectives and has begun to generate effects relevant to other impact dimensions, including societal and industrial aspects. The progress on expected high-impact outcomes generated that will contribute to scientific advances across disciplines are described below.

1) New NCY species have been selected as potential candidates to be applied in industries for SAF production. Furthermore, several waste-derived carbon sources have been obtained as potentially converted by NCY.

2) Disruptive yeast engineering strategies have been put in place. The CRISPRai multiplexing tool has been developed, a semi-rationally large DNA libraries using native mevalonate pathway transcription units for lipid production has been created and heterologous genes for terpene production in R. toruloides have been designed. The development of robust and reliable microbial systems will pave the way to produce SAF with a lower GHG emission burden with clear societal and environmental impact.

3) The first comparative catalytic results for metal-loaded zeolites in the hydroconversion of oleic acid have been produced progressing towards the discovery of new catalysts. An initial scientific basis for feasibility evaluation of fatty acid hydrocracking towards SAF production has been established. Preliminary experimental observations allowed identification of key performance indicators and technical aspects that will be crucial for future scalability and industrial implementation.

4) New SAF (economic) routes to attain SAF mandatory targets are being assessed. The selected processing and conversion approaches are providing the corresponding experimental data to design industrial models for the subsequent sustainability analyses. A policy analysis has been carried out through novel tools to assess policy impact data and devise effective strategies to enhance deployment opportunities for the novel SAF technologies. By using biowastes the economy of the SAF production process will be significantly reduced, thus the economic impacts of YAF are clear.

Dissemination activities like participation in conferences and industrial events, etc. have been performed which have undouble resulted in the increase of the scientific impacts of the generated results. As proved by the performed activities, communication of results and public engagement deliver higher societal impact and acceptability of SAF.

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