Microbial fuels have been touted as an alternative to petroleum fuel that could help make the aviation industry more sustainable. However, past ventures to commercialize the technology have proven unsuccessful. We explore the concept of microbial fuel and where it might be headed below.

Genetically engineered microbes

With airlines eager to meet sustainability targets and reduce emissions, various sustainable aviation fuels (SAF) are being researched and developed. One area with significant potential is microbial fuel, which harnesses genetically-altered microbes to convert carbon dioxide (CO2) into feedstock for alternative fuels.

United Airlines recently announced a new partnership with Houston-based biotech firm Cemvita Factory to create SAF using carbon dioxide, light, and synthetic microbes, essentially making jet fuel from thin air.

United Getty
US carriers believed the COVID testing requirement unnecessarily restricted international travel. Photo: Getty Images

Cemvita's method involves photosynthetic microbes called cyanobacteria that have been genetically engineered to create certain chemicals after interacting with light and carbon dioxide.

Although the subsequent jet fuel would still release emissions, this method could help airlines meet their net-zero goals as the process of creating the fuel captures carbon from the atmosphere.

Cemvita has incorporated synthetic biology technology in several other interesting projects. One such project involves genetically modified microbes in oil reservoirs that convert carbon dioxide into natural gas, simultaneously cutting CO2 emissions and increasing natural gas production.

Advances in technology

While microbial fuels are nothing new, prior attempts to create economically-viable fuel alternatives have proved unsuccessful. Developing affordable fuel at scale has proven a big stumbling block.

However, advances in genetic technology have made the process more feasible commercially. Genetic engineering tools are now more precise and allow developers to test and alter genetic material much quicker.

Cemvita said,

"Recent developments in synthetic biology (Artificial Intelligence, automation, and genetic engineering tools) have significantly reduced the cost and time for the modification of genes and enzymes of microbes allowing them to gain new capabilities."

Several companies have tried to make progress in the biofuels sector but without much success, including LS9, founded in 2005, and Joule Unlimited, founded in 2007. Both enterprises fizzled out within a decade.

Recent windfalls in climate-related funding are also helping. United's investment in Cemvita will begin at $5 million, and the door is open for further investment.

According to United,

"If performance targets are achieved, UAV and OLCV plan to form a joint venture to commercialize the technology. This includes funding projects such as pilot and demo plants, engineering studies, financing construction and operating SAF plants."

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Alternatives to traditional SAF

As the aviation industry sharpens its focus on sustainable fuels, the price of traditional feedstock like hydrogenated vegetable oils and tallows have gone up. This has been exacerbated by the conflict in Ukraine, as the country is the primary exporter of vegetable oils to the EU.

Alaska Airlines biofuel
Producing SAF at scale has proven a challenge. Photo: Alaska Airlines

Should SAF feedstock continue its upward trend in price, alternatives like microbial fuels could prove a game-changer for the aviation industry.

What are your thoughts on microbial fuels? Do you see the technology creating breakthroughs in the development of sustainable aviation fuels (SAF)? Let us know your insights in the comments.