press release
Researchers from BIAM have succeeded in producing heptane using only microorganisms and blue light. Published in Biofuel Research Journal on 1 September, this result paves the way for new solutions in green chemistry and sustainable fuel production.
To produce heptane without using a single drop of oil, researchers from the CEA, CNRS, and Aix-Marseille University working together at BIAM have designed a novel process combining synthetic biology, light and microbial co-culture: a first bacterium produces a precursor, octanoic acid, which a second bacterium transforms into heptane using a photoenzyme, i.e., an enzyme that uses light as an energy source. Tested in a photobioreactor, this system has achieved record yields.
Currently produced by petroleum distillation, heptane is a major component of fuels, particularly aviation fuels, and is also used as an industrial solvent. Its bio-based production thus opens up prospects for reducing CO₂ emissions – since it directly captures CO₂ already present in the atmosphere – while limiting the use of catalysts and chemical processes.
Key technological levers
- This breakthrough is based on several innovations:
- A blue light-activated promoter, which triggers and maintains production like a simple switch while replacing costly chemical inducers;
- Production yields multiplied by 12 when the central enzyme, Fatty Acid Photodecarboxylase (FAP), is fused with another protein, thioredoxin;
- A co-culture strategy that multiplies production by 14 by distributing biosynthesis across two complementary bacteria.
These results are based on thirty years of expertise in the field of biotechnology and more than a decade of fundamental research devoted to the discovery and exploration of FAP. Deciphering its mechanism, revealing its specific activity on octanoic acid, and studying its natural diversity were all necessary milestones in achieving this proof of concept.
Towards sustainable chemistry and fuels
The bacterial system developed has proven to be stable and reproducible over several days, which is essential for considering future upscaling. Another major advantage of this approach is that its selective production of pure heptane reduces purification costs, unlike other biological processes.
The bio-based heptane produced by this process could open up new prospects for the production of green solvents and other compounds of industrial interest, as well as contributing to the development of sustainable alternative fuels, particularly for aviation (SAF).
To this end, researchers are already working on ways to further improve the system’s performance: optimized light management, targeted evolution of the FAP to increase its robustness, and direct integration of genes into the bacterial genome to further simplify the processes.
[1] Institute of Biosciences and Biotechnology located at CEA Cadarache
Références
Ángel BACA-PORCEL, Poutoum Palakiyém SAMIRE, Bertrand LEGERET, Pascaline AUROY-TARRAGO, Florian VEILLET, Cécile GIACALONE, Stéphan CUINE, Solène MOULIN, Gilles PELTIER, Yonghua LI-BEISSON, Fred BEISSON, Damien SORIGUÉ