This Estonian scientist turns biggest culprit of the climate crisis (CO2) into renewable resource

By Aafke Eppinga

The country can make good use of these green technologies, as it is still heavily dependent on oil shale, a rock from which oil is produced.

Gas fermentation as solution

“The concentration of CO₂ in our atmosphere is higher than ever and still growing. The energy transition through decarbonization is happening, but heavy industry and transportation in particular will continue to rely on carbon for some time to come. Fermentation is one way to replace fossil carbon with recycled carbon,” says Kaspar Valgepea, assistant professor at the University of Tartu.

He holds the European Research Area (ERA) chair for Gas Fermentation Technologies and established the state-of-the-art GasFermTEC laboratory in Tartu in 2019. The laboratorium is part of the Estonian Centre for Biosustainability (ECB). With this green technology, the scientist aims to rid Estonia – and eventually the rest of the world – of two major problems of the climate crisis: excess of CO₂ in the atmosphere and ever-growing mountains of waste.

Traditional VS new generation gas fermentation

Traditional fermentation, in which sugar is the raw material, has been carried out on a large scale for hundreds of years. The most well-known fermentation process is conversion of sugars from malt or grapes into alcohol for beer and wine, using yeast.

Over the past twenty years, researchers and the industry have intensively worked on microorganisms that can grow on CO₂ as a carbon source, without the need of light for energy. The idea is simple: gas fermentation is a next-generation, sustainable biotechnology that uses harmful gases, such as CO or CO₂ as substrate, instead of sugar. Carbon emissions are thus “fed” to microorganisms that convert the pollution into valuable bio-products. 

Sustainable reuse of CO2

Valgepea’s research focuses not on the storage of CO₂, but on its sustainable reuse. His team is following two lines of research. “We want to better understand how the bacterial cell works. With that knowledge, we then want to modify the genetic code of the metabolism to convert CO₂ and CO into native products more efficiently. Or into new products, so that gas fermentation becomes smarter and more widespread.”

Thus, the Estonian scientist does not focus on specific CO₂ or CO streams. Instead, the emphasis is on understanding the bacteria and finding general solutions that actually find application in practice. In Tartu, different gas mixtures, environmental conditions and bacterial strains are tested and engineered. “Our task is to simulate situations as realistically as possible and identify what happens to the bacteria under certain conditions.”

Hardware and mathematical models

In the laboratory, hardware and mathematical models play an important role. “We can replicate and model the cell using data. For example, we can see what happens to a cell if we feed more gas to it. Or modify the genetic code of metabolism so that we can make the process of gas fermentation more efficient. In this way, we know within five seconds how the cell responds, whereas in a real-life experiment it would take weeks.”

“We want to better understand how the bacterial cell works. With that knowledge, we then want to modify the genetic code of the metabolism to convert CO₂ and CO into native products more efficiently.”

Kaspar Valgepea

Unique laboratory

The laboratory in Tartu is unique. Worldwide, there are only a handful of similar facilities allowing replication of industrial-like conditions at a laboratory scale. Valgepea gained experience during his postdoc at the University of Queensland in Australia. For example, the research team he was part of developed a bacterial strain that converts waste gas into a biodegradable bioplastic together with the American biotech company LanzaTech.

When the opportunity came along to start up a gas fermentation lab in his home country, he didn’t hesitate for a moment. He has been at it for three years now and is running a fully functioning facility. He still works closely with both LanzaTech and the Australian lab. Here he is also partnering with local companies. “Ideas can turn out great in the lab, but they also have to be applicable on industrial scale.”

Together with industry leader LanzaTech, GasFermTEC is working on improving the already commercialised gas fermentation process through process optimisation and engineering of bacteria.

Complicated research

Not many research groups or companies are working on the technology because the research is complicated. Fermenting waste gases into useful products can take place in the absence of oxygen. “You can’t just buy standard equipment and start a laboratory. Any mistake you make with oxygen will cause your experiment to fail. That makes everything take a lot of time.”

High expectations

Valgepea has high hopes for biotechnology in general and hopes that the Estonian government sees that too. “When Estonia allocated 100 million euros of its EU recovery plan for a Green Fund, Estonia’s three largest universities put forward ideas how to take bioscience research in our country to the next level. We hope the government will support our initiative.”

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