“Synthetic biology advances our ability to engineer living systems to address some of the world’s biggest sustainability challenges, allowing us to rethink how we meet human needs on a planetary scale,” said Michael C. Jewett, professor of bioengineering in the Schools of Engineering and Medicine.

In this Q&A, Jewett explains a bit of background about this field and exciting projects already in the works to enable new solutions for planetary health.

What is synthetic biology? 

Synthetic biology is a field that uses engineering principles to advance our ability to build with biology. Similar to how software developers write code to instruct computers, synthetic biologists write DNA to guide biological systems in performing specific tasks. What’s so cool is that, unlike computer programs, biology is not just about bits (i.e., information), it’s about bits and atoms … and you can build stuff with atoms. We can now engineer biological systems to address a wide range of needs by composing or building biological systems – from compostable materials to cellular therapies to the future of food.

What’s an example of a synthetic biology innovation with a positive environmental impact? 

One example is transforming atmospheric carbon into valuable products. Most of the things around us, from our shoes, polyester t-shirts, and toothbrushes, to the paint on the walls, are made from carbon-based chemicals derived from fossil fuels, which release CO₂ into the atmosphere when made. If we can teach microbes to capture atmospheric carbon and turn it into valuable materials, we can reduce our dependence on fossil fuels.

In collaboration with Lanzatech, my lab learned how to engineer a bacterium called Clostridium to consume carbon dioxide and produce sustainable chemicals. (Full disclosure: I’m on the scientific advisory board of Lanzatech.) We engineer these bacteria to produce chemicals used in everything from disinfectants to jet fuels.

How does this process work? 

Think of it like giving a video game character new superpowers. We engineer Clostridium by introducing genes that allow the bacteria to have new abilities, such as producing useful chemicals. As these microbes grow, they consume above-ground carbon and recycle it into chemicals like acetone or isopropanol. Unlike traditional petroleum-based processes that emit CO₂, our engineered microbes lock CO₂ into the product itself. For every kilogram of product made, there is the potential for up to 1.5 kilograms of CO₂ to be removed from the atmosphere. The base organism used is found naturally in various environments and is generally considered safe, like conventional yeast.

What other ways can we engineer biology to address sustainability challenges? 

Synthetic biology holds promise to address some of the most pressing sustainability challenges across multiple fields.

1. Chemical manufacturing often relies on reactions that require toxic chemicals and a lot of energy. My lab is advancing green chemistry by exploring ways to engineer enzymes capable of catalyzing chemical reactions under milder conditions, reducing energy consumption and the need for toxic solvents, and making industrial processes more environmentally friendly and sustainable.
2. Vayu Hill-Maini, an assistant professor of bioengineering, uses synthetic biology to engineer microorganisms to convert waste products into protein-rich foods. This creates new solutions for global food security in areas with limited food resources. This work could revolutionize how we think about food production, turning what would otherwise be discarded into a valuable resource.
3. Jenn Brophy, an assistant professor of bioengineering, uses synthetic biology for sustainable agriculture. Jenn is engineering plants to withstand extreme environmental conditions, such as severe drought and heat, which are becoming more frequent as global temperatures continue to rise. She does this by developing synthetic genetic circuits that reprogram plant growth and create more resilient crops.
4. Professors Chris Francis and Soichi Wakatsuki are working on nitrification in agricultural soils. We currently depend on nitrogen-based fertilizers to increase agricultural yields to feed the world, but that nitrogen is also consumed by microorganisms. That means less efficient crop production and increased greenhouse gas emissions. Chris and Soichi are working to produce active ammonia monooxygenase enzymes and improved nitrification inhibitors to control this microbial process. (Chris is a professor of Earth systems science and of oceans, and Soichi is a professor of photon science and of structural biology.)

What synthetic biology application in sustainability are you most excited about?

I’m excited about leveraging biology to accelerate carbon capture on a massive scale. Beyond engineered microbes, my lab is also exploring natural enzymes, like carbonic anhydrase, that efficiently convert CO₂ into stable carbonates (like rocks). The challenge is to make these enzymes stable and efficient enough for large-scale carbon removal. If we can succeed, this could remove CO₂ from the atmosphere thousands of times faster than natural processes.

Combining machine learning with synthetic biology also excites me. We can use machine learning to accelerate the design of proteins with specific functions. For example, we are developing enzymes that will change how we make sustainable chemicals.

Helen Dang is a Science Program Manager at Stanford. Follow Helen on LinkedIn