Turning Methane into Meat to Save the Planet
Microbes that turn methane into meat? It’s not magic, alchemy, or science fiction. It’s exactly what Dr. Ezhil Subbian and her team at String Bio are working on. They could just repurpose one of the major drivers of climate change — methane — into an appetizing animal-free meat product.
Dr. Subbian joined me on our January 15 episode of the Business for Good podcast to talk about why she started String Bio, how its microbe-nourishing methane method works, and much more.
Biotech experience to solve the world’s meat problem
String Bio started in Silicon Valley, but it is now based in Bangalore, in the southwest of India. In 2022 it closed on a Series B round totaling $20 million. Today, the company is working to increase its capacity to get its microbial protein ingredients to market.
Consumer demand for meat is skyrocketing in Asia. Dr. Subbian, originally a researcher in the biotechnology industry, took on the mantle of CEO when she and her co-founder decided to address this need by producing alternative meat proteins through the methane fermentation process.
The recipient of a Women Transforming India Award from the United Nations, Dr. Subbian earned a degree in industrial and biotechnology engineering at Anna University, Chennai. She went on to earn a PhD in molecular biology and biochemistry at Oregon Health and Science University in Portland. She subsequently developed insights into the fermentation process based on her two decades of experience developing bio-based applications in Silicon Valley.
Methane power for the people
If you care about solving the problem of climate change and you hear the words “meat” and “methane,” you’ll probably think of all the methane emissions from cattle farmed for beef production. After carbon dioxide, methane is the biggest greenhouse gas accelerating climate change.
Learning about Dr. Subbian’s work might make you see methane differently. Her focus is on diverting methane that would otherwise contribute to the greenhouse effect into feeding a special class of methane-metabolizing microbes. The process of fermentation then leads to protein-rich ingredients that can be used to produce a variety of alternative meats.
A focused B2B identity
String Bio isn’t a methane producer in itself. Rather, it works with upstream methane producers, including oil and gas companies, to use that methane more wisely to assist in the production of food. String Bio provides an economically attractive carbon-offset alternative to releasing all that methane into the atmosphere.
Then, as a B2B company, String Bio offers its protein-rich ingredients to partners that use them to formulate specific alternative meat applications.
In 2017, after spending its first four years refining its method of gas fermentation, String Bio raised its first $2.5 million round of outside funding based on proteins that could be used in the animal nutrition sector.
Making friends with methane-loving bacteria
The ancient science of fermentation has a key role to play in the modern alternative protein space, and Dr. Subbian’s professional experience has made her one of fermentation’s biggest champions.
Like liquid substrates such as corn and sugar, methane is a high-energy carbon source that supports the process of fermentation. Leveraging the potency of methane to drive protein-producing fermentation instead of climate change offers a carbon-negative method for solving two big problems at once.
The organisms the company uses are different than those used in fermentation with corn sugar. In the case of String Bio, the methane-metabolizing organisms are called methanotrophs, which are present in nature in areas like wetlands and rice paddies.
Because methanotrophs only gravitate toward using methane, not carbon, as a feedstock, there is a lower chance of contamination in the facility, given that only methane is present.
Humankind has historically burned methane for heat or fuel for transportation. We’ve also used a catalytic process to turn it into methanol to produce plastics, paints, and other everyday products.
But the String Bio team is doing something new with methane. The company has created its proprietary String Integrated Methane platform (SIMP), which is “a collection of engineering solutions,” Dr. Subbian told us, that supports fermentation and allows her team to convert methane into a variety of value-added products.
Remember also that biogas is about two-thirds methane. So String Bio is working to obtain biogas from producers of municipal solid waste. Once the waste undergoes aerobic conversion into biogas, it becomes a rich source of methane feedstock for the fermentation process.
The result: String Bio feeds the methane to microscopic organisms, which make the proteins that go into consumer-facing alternative meat products.
Dr. Subbian notes that her company has developed several different protein types, each with its own distinctive texture and flavor. One offers a neutral flavor that makes it highly versatile, while another is similar in taste to chicken nuggets.
Scaling for the future
Basing its work in India has proven both a challenge and an opportunity for String Bio. For one thing, Silicon Valley funders often won’t invest without meeting the founder and touring a facility. Plus, India-based funders are typically risk-averse when it comes to emerging companies. On the other hand, the costs of innovation and scaling went down the minute the company relocated.
With its $20 million in Series B funding, String Bio will continue scaling up with the addition of new commercial plants. One of these plants will use biogas as its methane source.
And, as the only company operating in Asia that has used biotechnology to facilitate a methane-based value chain, String Bio is looking at using its methane fermentation process for additional commercial applications.
So go check out this interview. You’ll likely be as inspired as I am about String Bio’s work.
