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This episode of Buff Innovator Insights features Dr. Noah Fierer, a professor in the Department of Ecology and Evolutionary Biology and director of the  at ²ÊÃñ±¦µä. We’ll learn about his natural curiosity for learning, and his unexpected and enduring passion for ... SOIL! Get a glimpse into the hidden world of microbes, the functions they serve, and how Dr. Fierer's research can help us understand and improve the health of our environment and ourselves. 

Terri Fiez

Hello. I'm your host, Terri Fiez, vice chancellor for research and innovation at the ²ÊÃñ±¦µä. Welcome to Buff Innovator Insights. This podcast features some of the most innovative ideas in the world and introduces you to the people behind the innovations, from how they got started, to how they're changing the future for all of us. Today, we'll meet Dr. Noah Fierer, a professor in the Department of Ecology and Evolutionary Biology, as well as the Cooperative Institute for Research and Environmental Science and director of the Center of Microbial Exploration at ²ÊÃñ±¦µä. He's interested in the distribution and roles of microscopic organisms in all kinds of environments, from the dust and plumbing in your homes, to the soil beneath our feet, and he studies how microbes influence the health and function of ecosystems, plants, and animals, including humans.

As director of the Center for Microbial Exploration, Dr. Fierer brings together scientists with expertise in microbiology to collaborate on everything from gut microbes to groundwater. He studied biology at Oberlin before earning his PhD in soil ecology from the University of California, Santa Barbara. During today's podcast, we'll hear about how growing up in rural Pennsylvania cultivated his natural curiosity for learning and especially his budding interest in science. He tells us about the variety of educational and research areas he sampled before unexpectedly discovering his passion for, you won't believe this, soil. He gives us a glimpse into the hidden world of microbes, the functions they serve and how his research aims to help us understand and improve the health of our environment and ourselves. Let's meet Dr. Noah Fierer.

Well, hi, Noah. Thank you for joining me today for this interview.

Dr. Noah Fierer

No, Thank you, Terri.

Terri Fiez

So let's get started. You grew up in the country in Pennsylvania. What did a typical day look like for you as a kid?

Dr. Noah Fierer

Yeah, so correct. I grew up in rural Pennsylvania in the woods and I was one of four kids and I'm sure my parents would agree, but we were kind of a handful. So we got thrown outside a lot. "Go outside, don't come back for a while." So we spent a lot of time when we weren't in school or doing school related activities or other things, we were outside playing in the woods, doing all sorts of exploring, just doing what we wanted to do. It was great.

Terri Fiez

How would you describe your mom and dad?

Dr. Noah Fierer

Patient. I know for a fact that we were definitely a handful, four energetic kids, but yeah, incredibly patient and also really valued education, both formal education and informal education. Just getting us to learn about the world around us. That was incredibly valuable.

Terri Fiez

So not only did you live in the country, but you would go camping and do a lot of vacations that were more in the outdoors too.

Dr. Noah Fierer

Yeah. We spent a lot of time, both in the winter and the summer. In the winter we would go on these cross-country skiing adventures, and in the summer we'd do a lot of backpacking. We'd pack up the car, drive somewhere and then they'd set us out in the woods for a while, in the wilderness, and we traveled all over the U.S, usually driving places, but got to see lots of beautiful place. Looking back now, I really appreciated those experiences, just getting to see lots of beautiful natural areas.

Terri Fiez

So then when you were in school, you had to go into town for school. What do you remember about school and were you a good student?

Dr. Noah Fierer

I think it depends on how you define good student. I know I got good grades and stuff like that, but I was definitely a little bit, shall we say, hyperactive. So I wasn't necessarily the student that sits there quietly. I spent a lot of time outside the classroom looking in because I was, shall we say, disruptive. But I very much enjoyed school and enjoyed lots of different topics. Perhaps not surprisingly, I really loved science, particularly biology. I really loved history, English. I really loved writing, which is a skill that's served me well as I've moved on with my scientific career, because a lot of what we do is writing, so it helps to like writing. I wasn't the biggest fan of math. I did okay in math, but I wouldn't say it was my favorite topic. I think there's this idea that scientists must love math. If you're going to be a scientist, you have to love math. That's definitely true in some disciplines, but that wasn't necessarily true in my case. I know enough math to get by, but it wasn't necessarily my favorite topic as a kid.

Terri Fiez

So then as you graduated from high school, how did you think about college and what were your plans as you went to college?

Dr. Noah Fierer

Well, I was one of these students that I didn't really know exactly what I wanted to do. I wasn't like, "I want to study specifically this topic, or I want to major in this topic." I wasn't sure. I was interested in lots of different things. So I ended up at Oberlin College in Ohio, which is a liberal arts school. One reason I wanted to go there was because it is a liberal arts school so you get exposed to and have opportunities to study a wide range of different topics. That's what I did, definitely for the first two years. I sort of dabbled around and took a lot of different courses in different areas before finally settling on a major in biology.

Terri Fiez

So you graduated with a biology degree and then spent the next four years doing a range of different jobs. Talk about what those different jobs were.

Dr. Noah Fierer

Yeah. So after undergraduate, graduated with a biology degree, I wasn't quite sure what I wanted to do. So I spent about four years basically taking any job I could get, particularly jobs related to biology. So I spent some time in the Pacific Northwest working as a field technician, so working on other projects related to birds or surveying trees and even salamanders. I spent some time in Israel studying gerbils in the desert, which was a lot of fun, but basically just a wide range of projects where people needed help and they were willing to pay me to work on these projects.

Terri Fiez

So at some point you decided that you wanted to go back and get a PhD. What prompted you to do that, and then how did you approach it?

Dr. Noah Fierer

Well, at that point I was pretty confident that I loved science and I also knew from working sort of as a technician or essentially technical support on a wide range of projects, that I wanted to sort of move beyond just doing projects or helping out with projects that were handed to me and I wanted to have more of a role in actually designing projects. So I quickly realized that to do that, I needed to get a PhD.

Terri Fiez

Where did you apply, and then where did you end up doing your PhD?

Dr. Noah Fierer

So working on a wide range of different projects before starting my PhD, it was really valuable because it taught me not only what I found interesting, but also what I found uninteresting or projects that I didn't want to work on. So for example, I spent a large period of time working on gerbils in the desert, which was really fun and it was really interesting, but I kind of realized I was a little ... we had to trap these durables and I didn't really like that very much, to be honest. They were always trying to bite you and they were covered in fleas and I was like, "Okay, I don't really want to work on animals." I kind of settled on, I got very interested in, believe it or not, in soils, which is not something that I would have anticipated as an undergraduate, but upon doing a lot of reading, I was like, "There's a lot of knowledge gaps here. There's a lot of things we don't know about and soils are really important."

So I got interested in soils and particular soil biology. So I decided to pursue a PhD in soil ecology. So I did a PhD at University of California, Santa Barbara with Josh Shimmel, who was my PhD advisor, and it was a great place to be interested in soil and related topics. I got a lot of exposure to not just basic soil science, but also understanding carbon cycling and nitrogen cycling and the organisms that live in soil. So it was really a great place to get sort of a well-rounded introduction to the study of soil, particularly from a biological perspective.

Terri Fiez

So what was your PhD research?

Dr. Noah Fierer

So my research primarily focused on carbon and nitrogen cycling in soil. So how does carbon get into soil? What happens to that carbon once it's in soil and also nitrogen, which is, of course, the key nutrient for plants. So really focused on dynamics of these elements in soil. Then towards the end of my PhD, I kind of got more interested in, "Okay, what organisms are responsible for a lot of these processes related to carbon cycling and nitrogen cycling in soil?" So that sort of led me down the path towards the end of my PhD to get more interested in the microbes, the microorganisms that are found in soil and what they're doing in the soil environment.

Terri Fiez

So what is a microbe?

Dr. Noah Fierer

A microbe is loosely defined just as organisms that we can't see with the naked eye. Of course, there's a broad range of organisms that can be classified as microbes. So these can include viruses, which of course, in the midst of a pandemic, we're all very familiar with. Could also include bacteria, could include many fungi or molds, as well as smaller protozoa and protists, for example.

Terri Fiez

After your PhD, I know you did a couple year postdoc and then joined ²ÊÃñ±¦µä as faculty. What has your research at ²ÊÃñ±¦µä been focused on?

Dr. Noah Fierer

So broadly my research here at University of Colorado focuses on the microbial diversity found out in the environment and my group over the years has studied microorganisms found in environments ranging from soil to the atmosphere to those microbes found on plants to even those microbes found living with us inside our homes. So in addition to what microbes are out there, so what's the diversity of microbes that are out there in various environments, my group also focuses on what they're doing. So one set of projects that we've been working on for a while is exploring the microorganisms found living with us inside our homes. So these microbes can be found in the dust blowing around inside our homes, or outside our homes, of course. They can be found in the plumbing in our water system that delivers water to our homes. So we've been really looking at what microbes are found in our homes and how do those microbes found in our homes vary depending on where you live and also how they may relate to our health.

Terri Fiez

Noah, back in 2013 when Boulder had a flood, I know that you mobilized with some other researchers to look at the effects of that flood. Can you talk about that?

Dr. Noah Fierer

Yeah. So in 2013 there was a flood that affected large portions of the city of Boulder and elsewhere, and pretty soon after the flood happened, I realized that there was sort of a unique research opportunity here. I know that sounds a little bit callous, but I'm a scientist, right? We see a natural disaster and we're like, "Oh, there's some cool science that can be done with this." In particular, what we wanted to look at, and I worked with a range of researchers across campus, including Shelly Miller in engineering here at ²ÊÃñ±¦µä, to look at, "Okay, how does flooding effect those microbes found in our homes?" What we did is we sampled more than 50 homes in South Boulder, half that had been flooded and half that didn't experience any water damage during the flooding event, and sampled the air inside the homes to look at the microbes.

What we found was actually quite surprising. So the sampling was done about four months after the flood and all the homes had been fixed, right? So there was no obvious water damage. The drywall had been replaced or removed, but still in those homes that were flooded, we saw large changes in the microbes found in the air inside those homes. In particular, we see much higher concentrations of molds or fungi in those homes, even though no mold was visible and no water damage was visible. What we think was happening was that these fungi or these molds are actually growing in the walls after the flooding event and sort of persisted for a period of time, even after the flooding event had occurred and restoration had happened.

Terri Fiez

Noah, when most of us grew up, our parents said that we needed to go out and play in the dirt, be exposed to dirt in order to help our immune systems. How do microbes play a part in that?

Dr. Noah Fierer

That's a good question and it's difficult to answer, because here's the problem; some microbes we don't want to be exposed to. Right? If I'm going to the salad bar and someone's sick and coughing all over it, I don't want to be exposed to those viruses or the bacteria that that person is shedding. At the same time, we know that we shouldn't live in a sterile environment. It's impossible to live in a sterile environment and being exposed to microbes is really critical to our health, including the development of healthy immune systems. The challenge is separating between those microbes that we want to avoid and those microbes we want to be exposed to. That's very much an area of ongoing research, is I would say it's good to play in the dirt, but that's coming from someone who loves soil and soil microbes.

But there does appear to be some truth to that. Being exposed to a broad diversity of microbes can be really helpful for improving the immune system functioning. The tricky part is knowing which particular microbes do we want to be exposed to and how? I don't want to lick a subway pole, but it might be beneficial to be exposed to natural soils or just the microbes blowing around in the air in a forest. So that's the real challenge is figuring out what activities or what particular microbes are most beneficial to our health.

Terri Fiez

One of the things that you've done more recently, I think 2018, you started the Center for Microbial Exploration. What is the goal of the center?

Dr. Noah Fierer

So we're very fortunate here at the University of Colorado to have amazing scientists. In particular, we have a large number of scientists that work broadly in the field of microbiology, or at least they have interests in microbiology. All of us share an interest in microorganisms, and that could be microbes in the human gut, it could be microbes in soil, it could be microbes in deep, subsurface groundwater. The goal of the center was to really bring all these people together, because we are scattered across campus, and sort of recognize that there's this interest and all this expertise and in particular encourage collaborations and bring new training opportunities for students and postdoctoral researchers on campus.

Terri Fiez

So in addition to all this research that you do, you also teach. What are the classes that you teach and what would be your favorite?

Dr. Noah Fierer

I've taught everything ranging from a large class like general microbiology to smaller, more focused graduate seminars for graduate students, for example, focused on very particular topics, including those sort of recent breakthroughs in science and so forth. But I would say my favorite course I've taught here at the University of Colorado is my soil ecology course, which I teach for undergraduates pretty much every year. So I've taught it at least, I think, 10 times now. I love it because I love soil and I love introducing students to soil and soil biology, and also how much we still don't know about soil, despite its importance. But many of the students have gone on to have careers in soil science or related topics. So it's been really great to see students be like, "Whoa, I didn't know soil or dirt could be so interesting."

Terri Fiez

That's great. So how has your field changed over the last few years and what are you excited about for the future?

Dr. Noah Fierer

So the field of microbial ecology, or essentially understanding the microbes that are out there and the environment and what they do, for a long time, or over the past, I'd say, 20 years, we have new methods available, including DNA-based methods that give us unparalleled insight into what microbes are out there in the environment. So for example, we can now take a sample of dust from your home or some soil from your garden or some tap water from your home and tell you what microbes are living in there. Over the past few years, we've long known that these microbes are important and now I think we're getting much better at not just who's there, what microbes are out there in these environments, but what are they doing?

It's been challenging because many of the microbes that we see in an environment, we don't know what they're doing. We don't have a name for them. They're not described species. We know that they're there, but we don't know what they're doing, how they might be influencing the health of humans or plants, for example. So I think the field is now going beyond like, "Okay, let's just describe who's there," to, "What are they doing and how does that influence our health or the health of animals or the health of plants?" Or just what role they're playing in their respective ecosystems.

Terri Fiez

That's really exciting. So what kind of breakthroughs do you think that we will see as a result of this?

Dr. Noah Fierer

Well, I think there's a lot of ongoing work that's showing how we can start manipulating microbes in the environment. This could be either direct manipulation, like adding in particular bacteria or adding in specific fungi, or it could be indirect, designing conditions that favor certain microbes over another to improve human health, animal health, plant health, ecosystem health. We see that most obviously ... many listeners may be familiar with work on microorganisms that live in our gut, and the role of probiotics. The fact that you can like take a pill with certain bacteria and that may improve gut health. We're still not there yet. I mean, it's still a lot of work that needs to be done to really make these approaches successful and it's not just restricted to the human gut.

There's a lot of interest now in are there particular microbes we can add to seeds or to add to soil to make crops drought resistant, for example, or more resistant to insect pests. So basically take advantage of this incredible diversity of microbes that's out there to benefit humans and make our systems more sustainable.

Terri Fiez

That's interesting. So what are you most proud of in your career?

Dr. Noah Fierer

Well, I've been really fortunate to work with some awesome early career researchers, and this includes people that have their PhD, post-doctoral researchers. It includes graduate students, it includes undergraduates, and it's been really fun to see these scientists grow and continue to grow as scientists and be able to see that process. The science we do can't be done without all these folks. I'm not in the lab on a daily basis running samples. Sometimes I wish I was, or I wish I was out in the field collecting samples. But to be honest, most of my time is spent responding to emails and talking on the phone or having meetings or working on proposals and so forth. So it's really all of these students and other researchers that are responsible for getting the science done. So it's been really fun working with students over the years and just the great ideas they bring and just how talented they are.

Terri Fiez

So what is your prediction for the next decade or two in your field and what will change and what breakthroughs we'll be able to find?

Dr. Noah Fierer

Well, we've known for a long time that microbes are important and this holds true in many environments. We know microbes are really important in soil, right? Many plants rely on microbes to grow. This isn't true in the human gut. It's not true on our skin. It's true in the atmosphere and water. The list goes on and on. Microbes are important both as pathogens, they get much of the press, particularly the last year and a half, things that we want to avoid or microbes that may cause disease in plants, for example. We've known about these pathogens, these sort of "bad microbes" for a long time, but we're starting to understand sort of more broadly that microbes are not all bad. Many of them are really critical role in the ecosystems. So now I think there's been a lot more focus, not just on the bad ones, but also on beneficial microbes or microbes that might be beneficial, whether we're talking about human health, plant health or the fertility of soils generally.

So I think that's what's very exciting about the field is that we're not just looking at those microbes we want to avoid or we want to get rid of from a given system. We're starting to look at what microbes do we want there, how can we use microbes directly or indirectly to improve agricultural sustainability, for example, or human health, and the list goes on. I mean, that work has been going on for a long time, but we're really in an exciting place where we have the tools and the conceptual approaches to really make big advances in using microbes for good.

Terri Fiez

Well, thank you, Noah. This has been a really fascinating conversation. I'm really glad that you could join me today.

Dr. Noah Fierer

Thank you, Terri.

Terri Fiez

I hope you enjoyed my conversation with Dr. Noah Fierer, professor of ecology and evolutionary biology, a member of the Cooperative Institute for Research in Environmental Sciences, and director of ²ÊÃñ±¦µä's Center of Microbial Exploration. To learn more about Dr. Fierer and the Center of Microbial Exploration, you can visit . Or for more Buff Innovator Insights episodes, you can also visit colorado.edu/rio/podcast. I'm your host and vice chancellor for research and innovation at ²ÊÃñ±¦µä, Terri Fiez. Thanks for joining me for this episode of Buff Innovator Insights. We'll see you next time.