How scientists created a chocolate bar out of thin air

US biotechnology startup Circe Bioscience has created molecules using microbes, including a type of fat that mimics cocoa butter to produce what it calls “the world’s first gas fermentation-based chocolate”.

The fat can also be used in confectionery products such as truffles and has a host of possible applications in the sweet sector. The scientific discovery could potentially address global food supply chain disruptions caused by the 2023-2024 cocoa shortage​ and subsequent cocoa prices that have been travelling on a ‘parabolic’ upward trajectory.

The technology, developed by a research team at the Wyss Institute for Biologically Inspired Engineering at Harvard University, converts greenhouse gases (GHG) such as hydrogen (H2) and carbon dioxide (CO2) into useful products such as fats and oils using microorganisms.

Using microbes to make ingredients

“We use synthetic biology to insert DNA from plants and animals into microbes,” Shannon Nangle, Co-Founder of Circe Bioscience, the startup originating from the Institute explains.

“We screen these microbes for the highest production, then grow them in fermentors in a process similar to brewing,” says Nangle. The microbes accumulate oil in their cells, which the Circe team then harvest and purify just like plant butters and oils.

The team then remove the microbes. “All that's left is the oil that is chemically identical to the oils found in nature,” she says. “We can make a variety of different butters and oils, from macadamia oil to specific palm oil fractions and even animal fats,” she says.

Using tech to replicate butter

As well as developing triglycerides - the molecules found in the fats, butters and oils that consumers eat and regularly use - Circe has also developed a platform that can create molecules found in sugars, fats, biodegradable plastics, and biofuels using only CO2, water and electricity as inputs.

'We urgently need to decarbonise industries and start reversing the damage we’ve caused to the planet' Pamela Silver, Professor of Biochemistry and Systems Biology at Harvard Medical School​

The impact this technology could have on decarbonising the food sector is clear.

“To ensure that the earth is habitable for future generations of humans, we urgently need to decarbonise industries and start reversing the damage we’ve caused to the planet,” said Pamela Silver, Professor of Biochemistry and Systems Biology at Harvard Medical School.

“Microbes are wonderful living machines that we can leverage to produce the things we need for everyone to live a happy, comfortable life while reducing pollution, land use, and fossil fuel consumption,” she says.

The Wyss Institute has entered into a global, exclusive licensing agreement with Circe, which received numerous awards for its microbe-to-chocolate concept during its development stage. At Wyss, the team was awarded $3.2 million from the US Department of Energy’s ARPA-E ECOSynBio programme. Co-founders Nangle and Marika Ziesack were also named as 2021 Activate Fellows before Nangle herself went on to be named an Innovator Under 35 in 2022 by MIT’s Tech Review.

Decarbonising confectionery creations

“The Wyss Institute supported Circe’s de-risking and commercialisation through our Institute Project program, which funds technologies with a high potential for positive impact,” says Lindsay Brownell, Editorial Content Manager at Wyss Institute for Biologically Inspired Engineering at Harvard University. Circe received this funding in 2021 and launched from the Institute later that year.

Overall, Circe has secured more than $8 million in funding, with support from investors such as Regen Ventures, Undeterred Capital, Ponderosa Ventures, Bee Partners, and Elementum Ventures.

Working with sustainable sources

“A paradigm shift to one of conservation, regeneration, and co-production using nature’s building materials rather than harsh chemicals is starting to happen, but at much too slow a pace,” said Don Ingber, Founding Director of the Wyss Institute. “The Circe team’s technology has the potential to speed up the transition to a future in which we work with nature to produce what we need rather than exploiting it,” he says.