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Shannon Nangle on Microbes and Mars

The Humans of the Wyss (HOW) series features members of the Wyss community discussing their work, the influences that shape them as scientists, and their collaborations at the Wyss Institute and beyond. 

Shannon Nangle’s ambitions are out of this world. She is developing bioplastics using metabolically engineered microbes that will not only help sustainability efforts on Earth, but will hopefully help humans survive on Mars. Learn more about Shannon and her work in this month’s Humans of the Wyss.

Shannon Nangle on Microbes and Mars

What are you working on?

As a postdoctoral fellow in Pam Silver’s lab I have engineered a microbe that—unlike yeast and E. coli—doesn’t need to eat sugar, instead using hydrogen and CO2 gas to produce fatty acids that are then polymerized as a form of fat storage. These polymers can be used to create materials  such as bioplastics that degrade naturally in the environment. We’ve also engineered the microbe to produce potent carbon-based fertilizers and feedstocks for other microorganisms. Our goal is to demonstrate that this gas-based industrial bioproduction method can be used to manufacture valuable products.

What real-world problem does this solve?

Shannon Nangle on Microbes and Mars
Fermenter that Shannon and her colleagues have nicknamed “Medusa.”

Gas-based industrial bioproduction has the potential to solve a number of problems related to environmental sustainability. One of those problems is plastic pollution. While developing microbes that can create a biodegradable plastic won’t remove existing plastics from the ocean, it can help decrease plastic pollution moving forward because these new plastics degrade faster with no additional processing. And if these products become widely adopted, they will also offset carbon emissions.

We are also engineering the same microbe to make industrial agriculture more sustainable. The vast majority of commercially engineered microbes are fed sugars from plants. If bioproduction becomes a major global industry, it will compete with human food production and cause an increase in the overall acres used for carbon-emitting agriculture. The microbe that we are engineering in our system produces sucrose to feed other microbes that are used for bioproduction, which could ensure that crops are used as food and also help combat climate change by offsetting the production of synthetic fertilizers.

What inspired you to get into this field?

My fundamental interest is actually consciousness. Consciousness is the generator of value and meaning, and as far as I can tell, meaning is fundamental to anything we think about. I think that’s the coolest thing. At the end of my undergrad career in neuroscience, I decided that rather than study the mechanisms of consciousness, I’d rather contribute to its continued existence by making sure humanity—the vessel of our consciousness—survives and expands into space. To me, the answer to achieving that is through synthetic biology. Not only could synthetic biology help ensure our Earth remains habitable, it could also be used to help us diversify our planetary portfolio and sustainably settle other planets. Biology is extremely versatile—as long as we have the raw starting materials, we can use the same biological technologies that function on Earth to live off the land on other planets. By contributing to research on Earth that is relevant for sustainability, I am also contributing to the effort to help humans survive off Earth, which will help humanity persist, so that our consciousness expands.

By contributing to research on Earth that is relevant for sustainability, I am also contributing to the effort to help humans survive off Earth, which will help humanity persist, so that our consciousness expands.

Shannon Nangle

What continues to motivate you?

I’m motivated by working toward the continued survival of humanity by contributing to the possibility of human life elsewhere, which would likely be on Mars, because it is the most Earth-like. It has tons of carbon (as CO2) and water, which are two of the most important inputs for life. As it happens, our microbial system uses CO2 and hydrogen from water as primary inputs, so we can imagine using it as a multipurpose platform for human settlements on-site. This is in line with a concept called In-Situ Resource Utilization, which basically means living off the land. It’s essential to Martian settlement, because the challenges of transporting all supplies to Mars from Earth would be insurmountable. Biology has the tools to transform the simple raw materials already present on Mars, which includes other crucial trace elements like sulfur, phosphorus, and nitrogen, into complex, useful materials to help humans survive off Earth.

What excites you most about your work?

It’s exciting that what I’m working on has only recently become possible. Industrial genetic engineering and gas fermentation have only really come online in the last five years or so. Now, we’re at the point where these technologies are becoming commercially viable. At the same time, with the advances in the space industry in recent years, sending humans to Mars is a real possibility. We’ve made more progress in the last five years than in the last fifty; we could do it. All of these elements are coming together to allow us to actually start planning how we would keep humans alive on Mars. It’s exciting, but it’s also terrifying that I am contributing to that conversation. I’m pretty new to the whole Mars scene, but it’s such a small community that every person counts. I cannot imagine working on anything else.

What are some of the challenges that you face?

For most of my work, I’ve just been doing normal molecular biology. The whole Mars thing is just a conceptual motivator at this point, so, my day-to-day trials in the lab are normal. The fermenter might stop working. We might not have enough air to feed the microbes. A pathway might not work how we would expect. My challenges are standard genetic engineering woes.

When you’re not in the lab, how do you like to spend your time?

I basically read all the time when I’m not working. I read books about the history of human society, books about what pre-agrarian cultures were like, and books about how statecraft has been approached through societies. I read primary literature on philosophy. Then I also read about science topics, like complex systems and fractals. I enjoy postmodern fiction, like Pynchon and DeLillo. I have so many stacks of books. When I get a new book, I’ll be so excited but then literally the next day I’ll find another one and decide I need to read that one first.

Sometimes, I listen to audio books and use Photoshop and a tablet to draw digital art. That way I can multitask.

If you had to choose an entirely different career path, what would it be?

If money is no object, then I’d go into philosophy. If money is an object, then aerospace engineering in some way — something with rockets.

What impact do you think your work will have in your lifetime?

I chose synthetic biology because it’s one of the most applied areas of the field. My Ph.D. was in crystallography, and when looking for my postdoc, I wanted to learn a field that has more immediate impact outside the lab. I was interested in joining the Wyss because its translational focus offered a path to industry.

When looking for my postdoc, I wanted to learn a field that has more immediate impact outside the lab. I was interested in joining the Wyss because its translational focus offered a path to industry.

Shannon Nangle

I think I’ll see human boots on Martian ground in my lifetime, but I’m not confident that I’ll see this technology or anything that I’ve worked on functioning on Mars, and that’s okay. I’m not doing this so I can retire on Mars. As long as I’m contributing to the effort that will allow people to survive long-term on Mars at some point, I am happy.

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