The Climate Biotech Podcast
Are you fascinated by the power and potential of biotechnology? Do you want to learn about cutting-edge innovations that can address climate change?
The Climate Biotech Podcast explores the most pressing problems at the intersection of climate and biology, and most importantly, how to solve them. Hosted by Dan Goodwin, a neuroscientist turned biotech enthusiast, the podcast features interviews with leading experts diving deep into topics like plant synthetic biology, mitochondrial engineering, gene editing, and more.
This podcast is powered by Homeworld Collective, a non-profit whose mission is to ignite the field of climate biotechnology.
The Climate Biotech Podcast
Weave Got Catalysts: Textile-immobilized Enzymes for CO2 Capture with Sonja Salmon
Sonja Salmon takes us on a fascinating journey through her 20-year quest to harness the power of enzymes and textiles to fight climate change. Her background in textile chemistry led to a deep understanding of natural polymers like cellulose and chitosan, which eventually connected to her fascination with enzymes during a 22-year career at the world's largest industrial enzyme company.
The heart of Salmon's innovation lies in immobilizing carbonic anhydrase. This remarkably fast enzyme converts carbon dioxide to bicarbonate, in this case onto textile surfaces. By coating cotton with chitosan and using reactive dye chemistry as a cross-linking agent, she creates a durable attachment that maintains the enzyme's activity while providing an ideal gas-liquid contact surface. This ingenious approach transforms ordinary fabric into a carbon capture device with minimal energy requirements.
What makes this approach so promising is its accessibility and scalability. The global textile manufacturing infrastructure already exists, and the materials involved are largely bio-derived and familiar to the industry.
Beyond carbon capture, Salmon's collaborative work extends to nitrogenase, an enzyme that could potentially replace the carbon-intensive Haber-Bosch process responsible for 2% of global CO2 emissions. Her vision of conductive textiles delivering electrons to immobilized nitrogenase points to a future where our clothes might literally help save the planet.
Join us to discover how this innovative scientist is weaving together biology and fabric into powerful climate solutions, and why she believes so strongly that we can—and must—take action on climate change. Check out Textile Biocatalysis Research online or biocatncsuedu to learn more about Professor Salmon's groundbreaking work.
Why do I think I can do something about carbon emissions? Because I can and I'm going to, because somebody has to, and it's me and a whole bunch of other people believing that there's something to be done about this that will make it happen.
Speaker 2:Welcome to the Climate Biotech Podcast, where we explore the most important problems at the intersection of climate and biology and, most importantly, how we can solve them. I'm Dan Goodwin, a technologist who spent years transitioning from software and neuroscience to a career in climate biotechnology. As your host, I will interview our sector's most creative voices, from scientists and entrepreneurs to policymakers and investors. All right, we are thrilled to welcome Professor Sonia Salmon for a discussion about climate biotech. Sonia Salmon is a professor at North Carolina State University with an amazing background in both textile chemistry, polymer science and biology. After academia, she went to a 22-year career in industrial R&D at the world's largest enzyme company, novozymes, where she developed sustainable biotech solutions across textiles, paper, water treatment, laundry detergents and now even carbon capture processes. Today she runs a very interesting group and we're going to talk about a lot of her collaborations, and I can give a little personal note here, which is that I've always loved talking with Sonia.
Speaker 2:We've met a couple of times in person when I've gone down to the research triangle, which I will make a couple of pitches for, because that is a very cool corner of the country and a lot of our. I would say I trace our relationship back to a workshop in carbon capture about two years ago where everyone was giving some lightning talks and Sonia just came in and gave the clearest articulation of how to engineer carbonic anhydrase in the context of direct air capture. And then that turned into a problem statement which you can look up online, which is lowering the KM of carbonic anhydrase to facilitate capture of CO2. If you fast forward, we were then very happy to support Sonia through the Garden Grants program and over the years I've been able to see Sonia be a really amazing professor and mentor and leader and I am super excited to have this conversation. So, without any further ado, sonia, thank you so much for joining us today. And who are you? Where?
Speaker 1:did you grow up, dan? Thanks so much for the very kind introduction. I am a wow. What am I? I am a person who, like I think all of of us, wants to do something useful with my life and I landed on a path in science because that's what struck me in an early age was a useful thing to learn about. I think maybe I gotta give a little high level path first and then maybe drop back into some maybe a few more personal notes. So my path really academically went from the study of textiles and you might wonder why I landed there, and I can tell about that.
Speaker 1:The study of textiles led me to learn about polymers, which are the molecular substructure of textile materials. Polymers led me to learning about particular kinds of polymers, like cellulose and chitosan, which are natural polymers. And then I had this really interesting question I wonder where they come from. Where does cellulose come from? My wonderful professors in the College of Textiles actually could not explain the answer to that. I actually had to go to the biochemistry department to learn where does cellulose come from?
Speaker 1:So that brought me into the world of biochemistry, and biochemistry brought me into the world of enzymes. And once I learned about enzymes there was no looking back. So enzymes being these amazing molecules that are so responsible for everything that happens in life. Anyway, I ended up between having some knowledge of textiles and some basic knowledge of enzymes, working for a company actually they were Novo Nordisk at the time. It goes way back. Then they were Novozymes, now they're Novo Nessus. They are the world's largest industrial biotech company. At the time they hired me, they were building a research group here in the state of North Carolina which is well known for its deep roots in the textile industry. They were setting up an applied research team to develop enzymes for applications in textiles. So they needed somebody who knew about textiles and knew about enzymes, and that just happened to be me.
Speaker 2:Amazing, and where did you grow up?
Speaker 1:I mostly grew up in North Carolina, in Greensboro. I have a large extended family in New Jersey and I did a short stint as a very young person in Los Angeles, california. I remember very distinctly the very steep cliffs plunging down to the ocean there and I remember that there was no snow in winter. The lakes did not freeze over like they did in New Jersey. Why can't you drive your car on the lakes in Los Angeles in December? How does Santa Claus bring your presents at Christmas time? This was a burning question to me as a five-year-old.
Speaker 2:Amazing. Now, also as a five-year-old, it makes me think of that story of you had to ask your professors where does cellulose come from. It feels like how a toddler asks where do babies come from? Exactly, Go to the hall, talk to dad. So on this note of you moving around as a kid, did you always know that you'd end up somehow at the tip of the spear between textile engineering and this atomic scale protein design?
Speaker 1:No, but it made sense. It all worked out into the mix. Here is I always had I have wonderful parents who encouraged me a lot and they their type of encouragement was not very supervisory. I was left on my own to figure things out, but mostly they were supporting me. They supported me to be interested and curious about what I'd be interested and curious about and watching them. Both my parents were skilled, very creative in ways. So I think this curiosity about creating and building things came from my parents and that stuck with me, so I would play around with different things. I my, my mother sewed, had a sewing machine, and so as a young person I started sewing things. I didn't sew clothes. I had a wonderful, fabulous collection of model horses. I thought I was going to be an Olympic equestrian superstar. Actually.
Speaker 2:There's still time.
Speaker 1:Not, it could be so. No, in my dreams I was going to have a huge horse farm somewhere in Montana at this time in my life. But my dreams taught me how to sew little blankets for my horses, and that has come in very handy now.
Speaker 2:Okay, Teenage Sonia sewing for model horses when you went to college, did you? It was straight to textiles.
Speaker 1:So the Wilson College of Textiles here at North Carolina State University I'm going to advertise. If you did not know about our wonderful, fabulous school here, please come check us out. If you are connected in any way with the textile industry or interested and curious in polymers, textiles and colors, come check us out. We are a small college on a big university, meaning we have a very family-oriented feel and we have access to a huge amount of resources and other expertise around the campus. So it's a really wonderful type of community. Also, the fact that our college is aligned with an industry means that there's very much purpose to all the research that we do, because the industry actually helps fund us. We have our own foundation. They help support scholarships, but we really hear from the industry what they need and what they care about, and so that's very motivating in terms of research.
Speaker 1:So that coincidence of me living in North Carolina and this college being very interested in attracting students they sent out people back in the day. They would send out recruiters to high schools and say, hey, have you ever thought about coming to textiles? And I thought, hey, I like to sew. Maybe I should go to the College of Textiles. Interestingly, the program I entered was the management program textile management.
Speaker 2:Wow.
Speaker 1:That was so the wrong place for me. Wrong place for me, fortunately. Fortunately one of my wonderful first instructors, a professor, michael Thiel. I took his introductory polymer chemistry class. He just pulled me aside one day and he said you're really good at chemistry. I don't think management is the right thing for you. Why don't you change degrees? So that was so. That was definitely a turning point in my life and I remember it well and it was extremely. I had no idea how powerful a piece of advice like that from somebody who just took the moment to notice Like why did he even notice? And I was so still am grateful for that.
Speaker 2:Yeah, that really hits home and I do want to make sure that we get a chance to talk about kind of the professional development, because that's a big spirit of this podcast, I think. On the technical side, I will say that when I talk with you I have this moment of oh, I've been overlooking the textile industry. To me it feels like such and this is totally the wrong way to put it, but it feels like this hidden gem of its huge leverage, really biocompatible, as a lot of it comes from bio right. Exactly, as you said, there's already a very active industry with a lot of process scale already done, and I'm really excited to have this conversation because I think people can leave thinking, oh man, I've totally missed this too. This is actually a very cool intersection. So just flagging that and your quick arc before we go into talking about nitrogenases, carbon capture and all that is that. Was it right out of undergrad that you went to Novozymes?
Speaker 1:I want to make sure I get that right. No, it was not. So I have a textile chemistry undergraduate degree and I didn't know what I wanted to do. I interviewed for some jobs, mainly at that would be like a supervisor of a textile mill, Not actually really what I that would not have been the right place for me.
Speaker 1:So I poked around a bit. I ended up working at the Peace Goods store, which is a fabric store, and told customers way too much that they ever wanted to know about their textiles Like that. They didn't need to be talking to me at that point, but anyway, that was fun and then did actually just some part-time work until in a lab, until I realized I just I feel like I'm not done learning yet. So I called the university back and I said what do you got for somebody who's not done learning yet? And again, a very fortunate circumstance my, who turned out to be my PhD advisor, sam Hudson, was starting his research program at the university, had an opening for a PhD student and was able to take me on, and he was already studying biopolymers. His biopolymer was chitosan. So I happen to know a lot about chitosan as a result of that Very interesting material. And that's how I ended up pardon the pun knitting together the kind of the hobby interest in textiles and the career development of learning about textiles and polymer science.
Speaker 2:Cool, I've got to double click on a technicality here, because when I think about chitosan, I don't think about textiles. When I think about chitosan, I think about insect, about textiles. When I think about chitosan, I think about insect shells. I was literally this morning just talking about how exoskeletons scale up to a certain point, but they don't hold. That's what I think about when I think chitosan. Yes, right.
Speaker 1:Yes, certainly. So it actually is not. If you try to make a fiber out of it, sorry folks, it's not the greatest fiber. It has some physical weaknesses in it. It's great as a medical textile. If you want to make patches and wound care sutures and stuff like that, that's great. If you're going to try to make an apparel fiber out of it, that's not going to work, so it's more like a specialty material. However, it is a natural polycation positive charge polymer. These are very rare in nature and they're very useful because you can they. Basically they behave as an adhesive. If you put them in their polycationic state, cellulose is negatively charged. Actually they're two. They're like Reese's and peanut butter, like peanut butter and chocolate together, like they'll stick to each other. Two great, two great polysaccharide flavors there that go great together. So it's useful material.
Speaker 2:In the molecular work I did in my PhD, people would always use the biotin streptavidin trick. They're like oh yeah, that's epic. Yeah, strongest non-covalent bond in biology, just use that for pulling something down. Is it the same thing in textile world where you're like, oh, just put cellulose and chitosan together?
Speaker 1:So the reason it became interesting for textiles though my advisor was spinning fiber out of it. So there is a purpose and a use for it in fibers. It has perhaps maybe more broad uses as a coating or for its polycationic properties, number one in the textile industry. A lot of dye in textile wastewater dyes are negatively charged. You got the polycadine. You can use it like a sponge. To take dye out of. Wastewater is one thing and on the flip side of that, during producing textiles you could put the chitosan coating on top of another fiber and have the dye kind of stick to the fabric better to begin with. So you have less waste when you're doing the dyeing initially.
Speaker 2:So it's for that kind of application that it became relevant. Wow, okay, there's going to be so many holes, we're going to fall into this conversation and it's going to come back.
Speaker 1:It's going to, it's coming back. Yeah, let's keep talking.
Speaker 2:Okay, but trying to keep some linear arc here, so you do your PhD. Was it all? Was the it was.
Speaker 1:Actually, I ended up doing a thing called shear precipitation. I was trying to make fibers, but I ended up making things called fibrids. I just had a little spinny rotor thing and was shearing the polymer solution into a coagulation bath and it made these sort of strands. They were thread but very short, more like a pulp that you would make paper out of. And I ended up going to the College of Natural Resources in their pulp and paper processing plant we made little hand sheets out of this chitosan material. That was really cool to be able to show that off as a show and tell of here. This used to be a crab oh, by the way, my sorry my source of crab. Like we go to the beach every year Great excuse. We used to shell our own shrimp. We're older now, we pay other people to shell our shrimp, but back in the day we were shelling our own shrimp, so we'd eat the shell, we'd eat the shrimp and I'd bring the shells back to the lab and I'd make my own chitosan. That was fun.
Speaker 2:Wow, I also love getting to see doing macro scale. Biology is always feels special to me. My benchmark, my starting spot, is computer science and basically protein scale or RNA scale. So when you can actually see these little fibrids floating around the tank, I can imagine that being really exciting. Okay, so then trying to step along. You could have done anything out of your PhD. Obviously a great opportunity to go work for Novo. I've always noticed your kind of executive sense, which surely must come from 20 years in a top industry. So what was that like? Was it several big projects? And what made you choose to go back to becoming a professor?
Speaker 1:Okay, a lot in that. I have to say I thoroughly enjoyed my journey at Nova Zymes. It's, at NovoNessus now, a very special place, incredible people who care passionately every single one of them cares so passionately about what they're doing, regardless and like across the spectrum of the jobs there, so it was a really special environment to work in and great hard I make it sound like glowingly wonderful. Not every day was glowingly wonderful, but the common purpose, the realization that society needs clean technology and that enzymes, which are the core of their business, are bio-based catalysts using minimal energy, having very favorable life cycle analysis, giving a chance to save water, energy time maybe not Time's always the hard one Water energy, reduced chemical load this was it just felt good, it felt really good to be working on that kind of a technology that could make a positive difference.
Speaker 2:And this was everything from laundry detergents to local catalysis.
Speaker 1:Yeah, you have not worked for an industrial enzyme supplier until you have washed laundry professionally.
Speaker 1:I say that a little bit tongue in cheek, but it is still true that the enzymes in laundry detergent are one of the stains actually have polymeric materials in them. So if you can cut those polymer stains into small pieces it's much easier to wash them away so you can reduce the temperature of the laundry and the amount of surfactant that goes into the laundry. And think about all of the washes that happen all the time and all that wastewater going. You really want to have things like enzymes in your laundry detergent but it means you have to wash a lot of laundry and work.
Speaker 2:It's very interesting for two reasons. One, there's this unsubstantiated fact that I've heard people throw around. I've never been able to find the primary source for it, but it's an estimate of the overall US power usage decrease because of enzymes in the laundry. Because of enzymes in the laundry and I've seen people say it's like a one or 2% less use of energy because people can clean their energy. They can clean their clothes at medium or cold rather than hot like they used to.
Speaker 1:Yeah, I would believe it. I don't know the statistic like personally, but it is a non-trivial amount of savings, definitely, and I think probably the statistic is even higher in Europe. Just that there was a cultural difference. In Europe there was a tendency to use hotter water to do your washes. The US, because of the style of washing machine, tended to use colder washes anyway. So in Europe it really made a difference. If you could go from a hot wash even to a warm wash would make a huge difference in the energy demand.
Speaker 2:Got it. And then the other thing that took me to stumble over laundry is when you start doing protein engineering in the context of climate, you immediately get into the techno-economic analysis and you realize that gosh proteins are really expensive compared to a lot of things.
Speaker 1:Compared to many things, but not all things.
Speaker 2:And then the people who take the bull case on proteins can do anything will immediately say look at laundry detergents.
Speaker 1:Those things.
Speaker 2:And my understanding and please correct me if I'm wrong is that it's laundry detergents that are the largest volume, lowest cost proteins that we produce.
Speaker 1:That would probably be in the right category. Biofuels would probably be the other one. Be in the right category. Biofuels would probably be the other one. So enzymes used to chop up starch, to make glucose, to feed to yeast, so that's feeding yeast to make bioethanol is a very large industry as well and also very cost conscious. So I think between the two of those, household care, which would be the laundry detergent group, and bioenergy would be the two kind of cost-conscious, most cost-conscious, and they are very large volume. That's how it works out commercially.
Speaker 2:And so you had this experience and then you chose to go back and be a professor, and we're all obviously thrilled about that. So when did you start your lab and what have been some of the topics that your lab has tackled?
Speaker 1:2017 is when I came back to my alma mater and they reached out to me. I wasn't actively looking, but they were in my backyard. Nc State University is in Raleigh, North Carolina, and that's I actually. I never moved from Raleigh. I did my degree here and then I have been living in Raleigh and the Novozyme site where I was working in Franklinton is about 30 miles north of Raleigh, so that was a manageable drive. But I have to say that northern Raleigh is growing a lot and they kept putting more and more traffic lights onto US 1. So the drive was not getting shorter, it was getting longer and longer and more cars. It was actually getting a bit taxing to make the drive every day. And then I just got the call from the place that's six miles from my house and I thought maybe I should think about this. It turns out that one cannot replace Sam Hudson at all, but his leaving the university or his going on phased retirement opened up a slot and they were recruiting for that position and asked me to apply and it worked out.
Speaker 2:You filled the shoes and then some of your PhD advisor the person that gave you the shot so long ago. That's beautiful. I think it's so good to have a professor who's got that much industrial experience. It's really good to be able to coach people on how to navigate the grantsmanship side of academia, but I think it's also really good to have that applied lens of what this might look like. There's other paths besides just academia. So I think, just if I was to pick a perfect professor, it would basically be someone who knows industry really well and knows how to succeed in academia. So I don't mean to be just your puff-out person, sonia, but I think that's really good that you brought that experience back to NC State.
Speaker 1:I think that's actually what motivates a lot of the faculty here. A number of them have industry experience and we do. That's what we feel is our new obligation. We've learned, we've had a good career and our new job is to pass that on to the next generation. And it's true, it's genuine. We had the benefit of such wonderful people helping us.
Speaker 2:And it's time to pay it forward Right on. So this is the point where we get to start kind of geeking out on exactly what this intersection of textiles and biotech looks like. And the two big things that I've got on my docket to explore together would be carbon dioxide capture and then nitrogenase, or, in general, your big project. I think. If I was to guess, maybe let's start with the carbon dioxide and then we can go back to the nitrogenase side if we have time. So the carbon dioxide project we at Homeworld got to know about because we were very happy to support you through the Homeworld Garden Grants project, and the way we think about garden grants is that it's a good problem stapled to a good solution, and it shouldn't be me talking about your work. I think it's up to you. Could you tell people a little bit about the problem that you've been working on and then what you've been doing to solve it?
Speaker 1:So, first of all, thank you. I do appreciate the garden grant very much and extremely admire what Homeworld Collective is doing. You guys are top notch, all of you, and it's really important for the community to have that kind of support and have that kind of voice and conversation that you're bringing Super thanks for that. My journey with Carbon Capture is pretty long. I'll try not to make it long, but it started back when I was in Novanessus. We had an innovation team, actually a scouting team, that was looking for the next big ideas. Right, you have your current products, but you always want to be working on what the next new products are going to be.
Speaker 1:And it was participating in one of these innovation teams that I first became aware in a more kind of concrete way about an enzyme called carbonic anhydrase. Concrete way, about an enzyme called carbonic anhydrase. Anybody probably who takes biochemistry or even maybe even biology class, you'll see carbonic anhydrase written in your textbook. It's always in a little table where they talk about enzymes and reaction rates and it's always listed up there with catalase, as being one of the fastest, kinetically fastest enzymes. It also happens to be on the molecular weight marker ladder. It happens to be bovine carbonic anhydrase or mammalian alpha carbonic anhydrase happens to be around 25 kilodalt, and so there are a couple of reasons why a lot of people in this space know about carbonic anhydrase without really having thought about carbonic anhydrase, know about carbonic anhydrase without really having thought about carbonic anhydrase.
Speaker 1:This enzyme came onto our radar from an outside. Call someone who approached us saying I'm working on a Department of Energy funded project and I need more enzyme. I can't afford to buy it at the very high price that it costs to buy it in a research catalog. You guys are the biggest enzyme producers. Can you make me some? And this was interesting call because at the time this was not a product in the product range and it wasn't a product because there wasn't a market for it. There wasn't a market for it because there was no price on carbon dioxide.
Speaker 1:That situation has finally changed somewhat. I would say it's way better than it was 20 years ago, but it's still a little bit of an interesting challenge to put a price on what is it worth to pull carbon dioxide out of an emissions gas or out of the air? So when you make a product, like any product, you want to have a market for it. So that was one of the basic reasons why it didn't exist as a product. There was no big market for it.
Speaker 1:But this opportunity this opportunity driven by a problem the problem being increasing concentration of CO2 in the atmosphere, leading to dramatic climate change which we are experiencing right now that was, at that time, still a bit hypothetical. Actually, 20 years ago that was still a bit hypothetical. Actually, 20 years ago that was still a theory that maybe a lot of people were not believing. Yeah, you and Klaus Lackner and a handful of weirdos saying that we need to draw it out, but it sounded so believable. Here we are burning fossil fuels.
Speaker 1:Carbon dioxide is a byproduct of combustion. Truth, end of story period. That is a true thing. When you burn carbon, you get carbon dioxide. And where does it go? It goes into the air, and if you have too much of it, you trap heat from the sun, because CO2 absorbs in the infrared and re-emits it at heat. It's a very simple mechanism, very well understood mechanism, why that happens. But there's this big problem.
Speaker 1:And then there's this enzyme that was brought under my radar. That said, hey, this enzyme is capable of rapidly converting carbon dioxide a sparingly soluble gas, a gas that does not like to dissolve in water. You can convert that to bicarbonate, an ion that is highly soluble in water, like sodium bicarbonate, like baking soda, that kind of bicarbonate. So this enzyme speeds up that reaction and that reaction is a way to selectively grab CO2 molecules out of mixed gas streams. So in an emissions gas you've got nitrogen, you've got oxygen, residual oxygen, maybe some other gases and a little bit of carbon dioxide. You don't care about those other gases, you just want to grab the carbon dioxide, and this enzyme could help you do it. I thought that was important. That's why I started chasing this enzyme.
Speaker 2:It was conversationally told to me oh, carbonic anhydrase is why when you drink soda water it goes still in your mouth.
Speaker 1:Oh, interesting. Yes, Weirdly, I'd never heard that, but you're probably right, you'd be the person to factor. Yes, I'm going to go spit in a Petri dish now you can. You can get. Yeah, it's a longer story, you can do a lot with catalase.
Speaker 2:That way, too, we won't go there right now. Cool, okay, first of all, big credit to people that were so far ahead of the curve right. And carbonic anhydrase, very important enzyme. I would say there's maybe like a big five enzymes that are super pivotal to climate. Carbonic anhydride is definitely one of them. What was your novel formulation of the problem that you were trying to solve?
Speaker 1:So at the time I started and sorry, yeah, I've lost track of your question Let me get back to your question originally. The problem at that time, 20 years ago, was you could buy a tiny amount of enzyme for a very high price. That was the only option. Today you could call 1-800-NOVONESSUS-whatever and do a deal with them and they would be happy to sell you tons of the enzyme. So please go do that.
Speaker 1:If you guys anybody listening to this has an opportunity to use the enzyme, it's not being able to make it that is an obstacle anymore. It's the market opportunity. So please, yeah, move down that road. The enzyme can be available to those who want to work with it commercially. So that was a huge step forward. Availability the possibility to make this enzyme at scale was incredibly important. This enzyme at scale was incredibly important, okay.
Speaker 1:But here's the thing there's been 70 years worth of development in carbon capture technologies abiotic, not involving enzymes. So they've been optimized for the solvents and the reactor designs and the packing materials and the energy flows. They have not been optimized to take advantage of what the enzyme can do, which is really overcome kinetic limitations. So here the current problem is to rethink how does that capture process work so that you can take advantage of this very fast enzyme under conditions where it can exhibit its very high reaction rates. And that's what brought me to looking at immobilized carbonic anhydrase not an enzyme that's dissolved in a liquid, which is how enzymes are often used, but enzymes attached to a solid surface so that you can hold the enzyme in place and let it run and carry out its catalysis over and over, like the catalytic converter in your car does that kind of approach?
Speaker 2:To quickly put this in context for listeners in the idea of a carbon capture device, you're going to have air flowing across something and you want that air to have the carbon dioxide go as quickly as possible into something right, and then you later then have to disengage that carbon dioxide into some sort of recipient endpoint, and so the default is that you just use a really nasty chemical with a super high pH, right, and then now you've got it dissolved, and then that's great, but then you have to somehow get the carbon dioxide out of this toxic chemical.
Speaker 1:To get it back out of the liquid can cost a lot of energy. So part of the challenge here is how to make that combination between the rate of getting it into the liquid and the cost of getting it back out of the liquid low enough so that you can, as concept has been, so that you can reuse the liquid. That's been the, that's been the driver in the conventional technology. I've been. The enzyme can help there. But the enzyme could also help in a quite different situation where really what you want to do is you want to get the carbon dioxide into the liquid and then you want to process the liquid to trap the CO2 in some way directly from the liquid without having to recycle the liquid. So that's another place where carbonic anhydrase has special merits.
Speaker 2:Really interesting, and I think it's important to articulate this immobilization importance, because I think my PhD was in synthetic biology in the context of neuroscience, and oftentimes even though we know not to, sometimes we think about the bag of biology mentality of, oh, it's just enzymes floating around, the solution and it'll do its thing.
Speaker 2:But then, when you think about an industrial context, if you had your carbonic anhydrase floating around in a fluid, you need to get the carbon dioxide out and then, preferably, you need to not lose the carbonic anhydrase while you're there, and it turns out that when you immobilize enzymes, it has some really great functional benefits as well. So I think one thing you're talking about is that you can just take the beads out or take the textiles out, and so you're not. If you hurt the fluid, you're not hurting the enzymes, but then you get really nice catalytic benefits when you've got things immobilized as well. And so I don't mean to be like I think you're the person to be talking about this, not me. But looking from the outside, looking in, it seems like enzyme design plus immobilization, plus system level thinking is one of the most important connections that I think every biotechnologist should be thinking about, and so the way you do this with textiles, I think is brilliant.
Speaker 1:Yeah, so that is a wonderful way to bring it back to the textile. The textile because of my background and experience with fibers and polymers, like, why would I even think about immobilizing enzymes on textiles? If you only imagined I had a 22 year career with an enzyme company, like, where would the textiles come in? It's just my academic background and my personal interest was related to these fibrous materials, which are beautiful, flexible. We wear them, they're so comfortable and you can derive them from nature and most beautiful natural fiber is photosynthetic. It is also grabbing CO2 out of the air with the help of sunlight and water. So if we can combine some of the attributes of these fibrous and polymer materials that come with nature and use those to help us track more carbon dioxide, this is all a good thing.
Speaker 1:So I am going to suddenly blast in here like a mental image of a sweaty t-shirt, because that's the quickest way to tell you about a gas liquid contactor. So imagine you are out jogging and you happen to be wearing a cotton t-shirt and it's a hot day. Your sweat from your body is going to absorb into that t-shirt and it's going to spread across the t-shirt. So you're going to get sweat all over and you're going to look yucky and people are not going to want to talk to you. But you have just made a great gas liquid contactor because there's a very thin liquid film spread throughout that surface. If I can also immobilize an enzyme right on that surface where you have that high gas liquid contact, then the enzyme is going to be just at the right place to interact with the CO2 gas molecule, to react it, to get caught in that liquid. And if I have a way to move that liquid continuously out of the system, then I can keep using that catalyst over and over again.
Speaker 2:The use of the capillary action is something I hadn't really considered.
Speaker 1:That is one of the most important things here. We call it wicking capillary action is something I hadn't really considered. That is one of the most important things here. That capillary we call it wicking Capillary action is exactly what's going on there.
Speaker 2:So you've got a material that has super high surface area to volume ratio is naturally derived, so presumably you can imagine engineering the polymers in some way. Should you want functional groups stapled onto it, you can somehow integrate enzymes onto that and then you can imagine some sort of physical deployment in which you're just letting wicking. Take the fluid flow, solve the fluid flow.
Speaker 1:Yes, yes, that's why I had mentioned I was doing some direct air capture experiments in my backyard. That's where that comes in. Everybody's got to do. You got to do an experiment either on your kitchen counter or in your shop, or in your bathroom or in your backyard. I've done I think I've done all of those actually.
Speaker 1:Yeah, I have a really forgiving family. So, yeah, I am an experimentalist. I need to see it Like. I need to pick it up and touch it. I've got my own little shop and I need to be able to build something and see it operating.
Speaker 1:So I'm doing carbon capture in my backyard with solvent. Currently it's 1% potassium carbonate. This is like my. This is my okay. Ph 10, 10 and a half-ish or so. You could spill it on you. You don't want to leave it there, but it's not going to hurt. You Don't put it in your eyes. Friends, Wear your safety glasses.
Speaker 1:But the point is I can do this experiment in my backyard with safe materials, the enzymes immobilized on my cotton fabric and I can capture carbon. Right now I'm working on trying to develop the design so they can be more efficient. And that comes back actually to this idea of the garden grant trying to make that interaction between the enzyme and the textile more efficient and even engineer the enzyme so that it can be more efficient in that reaction. But you need to be able to test that because it's extremely hard to model these multi-phase flowing systems. They're very complex. You need quite sophisticated approaches to try it's. Computational fluid dynamics is what you need to be able to model these systems and that takes a lot of time. So we're actually doing them in parallel. I have some collaborators who actually have that competency to do computational fluid dynamics, so we're looking at that in parallel with some of the kind of more experimentalist things that I do.
Speaker 2:So that's a lot of variables. What are the most important ones when you're designing this thing? The carbon dioxide, sorry, carbonic anhydrase on a fabric in the context of direct air capture. What are the most important engineering variables there?
Speaker 1:I am learning as I go all the time. The ones that I thought were super important to start with become less important as we figure them out, and then more new ones become more important. There is a really fun variable. I'm just going to push this one out there because it's what all the any professional who does gas liquid contactors, regardless if it's got enzymes involved or not. They're going to talk about a concept of pressure drop.
Speaker 1:That is, when you're blowing air or gas through a reactor and there is something in the reactor, that physical presence of that thing in the reactor is going to slow the air down, and so you need to have a stronger blower.
Speaker 1:If that resistance force to the air passing through is too high, you need a powerful blower to push the air through, and that powerful blower costs energy. So it's actually the energy requirement of pushing gas through these reactors that is very, from an economic point of view, is a very important factor, and so you want a low pressure drop. You want to have contactor materials that will allow the air to flow through easily but still provide that high gas liquid contact through easily but still provide that high gas-liquid contact. So this is one very important parameter. That sounds a bit like where did that come from? It flew in from outer space, but it's really critical, and so part of the designing for the enzyme to fit into this reactor is to figure out how to get the enzyme onto these special shapes that can carry out this gas-liquid contact very efficiently with low energy requirement.
Speaker 2:And this is where we get to pull from your textile background, right, because the easy question to ask, the annoying question to ask is why is this hard? It sounds pretty good, just put a t-shirt in the backyard between two buckets done. But I know that there's a lot of tricks in the textile industry that you've picked up that I think you can understand and you can see where the leverage points are to bring in new biotech, and this, I think, is what listeners are curious about. It's like why does textiles play this role? What are these dark arts? Besides knowing that we can make a bunch of t-shirts, yeah, question is yeah, what are some of the textile tricks you can bring to bear?
Speaker 1:Dan, I love that you asked the question and even that you asked it in that way so I could answer in this way. My mission is to make it as easy as possible. I am trying to make this process as easy and safe and efficient and available as possible. Textiles Number one.
Speaker 1:Textiles is an established industry around the world. All of the infrastructure for making textiles already exists and it can move around. You can build it here, build it there, move it here and move it there. There's a huge infrastructure already existing that can make the type of materials that would work for this process. That's huge. We're going to use the textiles as our packing material, so we figured out we can make the packing material. Now we have to have a smart way of getting the enzymes on there to stay on there and perform well. There are probably lots and lots of ways of doing this. The way I chose to do it was based on what my expertise is, and my expertise is related to chitosan. I told you it would come back, so I'm going to use chitosan as a coating on my cotton textiles.
Speaker 1:These are both bio-derived polymers, so essentially coming from nature, helping draw down CO2 from the atmosphere. Anyway, I'm going to use the chitosan because chitosan has a different functional group in it than cellulose. Chemically it's almost identical to cellulose, except the c2 position has an amine group on it. Look it up if you don't know what I meant there. But the amine group allows you to do much more mild covalent chemistry. You can create new chemical bonds much more easily with an amine group than with the hydroxy groups that are already on cellulose. So by putting the chitosan on the cellulose, on the cotton, we've made it much easier to carry out chemical reactions under mild conditions. And that's the Achilles heel of enzymes. They are proteins and if you beat them up too hard it's like an egg. If you throw the egg in the frying pan it's going to cook. So if you treat the enzyme too hard it will unfold, it will denature and it won't work anymore. So we created this recipe to make a mild reaction condition so that we can apply the enzyme and cross-link it onto the polymer and hold it there. And the way we're doing it, the novel way we're doing it, the way we're chasing right now is to actually use a dye chemistry.
Speaker 1:There's a category of dyes known in the textile industry, or I could say a sub-category of dyes called reactive dyes, and a sub-sub-category of those called bifunctional reactive dyes and a sub-subcategory of those called bifunctional reactive dyes. So these bifunctional reactive dyes can act as cross-linking agents between the chitosan that's coated on the cotton and the enzyme, which also has amine groups on its surface and is able to react with that same cross-linking agent. So we have taken cotton, chitosan and enzymes, which are all bio-derived, and we have added a small amount of one synthetic chemical ingredient. The reactive dye is made by synthetic chemistry. But that reactive dye allows us, with relatively small amount, allows us to give a very durable chemical attachment and those kinds of dyes are already used around the world in the textile industry today. We do not need to teach anything new there. The only thing new is a little bit of chemistry around the coating process and here's some enzyme and go to it.
Speaker 2:It's so good, like I'm obviously people listening to this can't see, but I'm just like smiling and nodding the whole time because it's like this is the exact thing that you look for is like, how do you take a molecular scale biotech solution and then chart any sort of plausible path, right, and there's not many people like put it on a plant, good luck. Yeah. Put it on a plant, good luck, yeah. Put it in a t-shirt, that's different, and so I really just I'm so excited by this insight that you can use dye chemistry and everyone listening this is wearing something that's been dyed right and then using that as a carbon capture and possibly even a lot of other. This this to me feels like an approach that a lot of other people who work with proteins first could think about. If you're okay talking about it, I think that you're going to scale this technology up and eventually it's going to leave your lab right.
Speaker 1:Yes, we're actively working on that. So it was with the support of NC State University, which actually is pretty highly ranked for its technology transfer and supporting small businesses and establishing spin-out companies. I wasn't planning to start a company, but the way things unfolded it made sense and actually last year, together with a co-founder, I started a company called Trellis Eco Technologies. We're a very small, very private company right now, but we are set up to work on commercializing this technology because we think it's got legs on it. We think it deserves to go out into field testing. Basically, that would be. The next step is we can scale up the material and it needs to get field tested so that folks can actually see what it's capable of and that we can find out where it fails and fix where it fails and move on from there.
Speaker 2:Yeah, and this feels exactly when US academia is working its best. You take the wild ideas, you build it in academia and then, at a certain point, the problems can be framed in a free market way.
Speaker 1:So I'm really excited to see what Chaliceco does. Yeah, me too, and I really appreciate actually the community of support, like the climate, biotech community, other support. I've had a huge amount of support from so many people friends, folks I didn't know before to help move this along. It's hard Like starting a company. Also, I haven't stopped. I've got a full-time job here. I'm on the faculty, I haven't stopped that. And so it gives a certain kind of limitation on exactly what you can do. But anybody starting that journey needs to do it in the way that's right for them, and so I'm not telling anybody else to do this the way I've done it. I'm just saying the way I'm doing it is the right way for me and the right way for me to see how to help bring this technology forward.
Speaker 1:This project, as I worked on it over, it is actually now 20 years. For many years I was saying it's almost 20 years. It's almost 20 years. You're like, oh my God, why? How have you been working on it for 20 years and haven't figured it out yet? Okay, it's supposed to be year 20. That's the magic year right when you're supposed to finally push through and get it commercialized. Let's see, maybe it'll happen.
Speaker 2:Yeah, it's amazing. All right, so we have 10 minutes left, and I did this narrative sin of mentioning nitrogenase, but then we didn't come back to it. So what I'd love to do is, as much as we can, just spend a few minutes on the larger consortium of projects that you've been working on. I'm assuming that every person who works in biotech VC or climate VC is hearing this. Wait, 20 years as a professor, great black belt experience now being deployed in a totally plausible way. I'm hoping you're going to get a lot of inbounds on that, and so that's where we can move forward and just spend a few minutes hearing about some of the other things that you're working on, and then we'll go to the four rapid fire questions. Nitrogenase you're working with Professor Amy Grunden, who's amazing. That was one of those conversations when I talked with her where I just left being like, yep, I don't know a single thing about biology. I'm a fake, but nitrogenase is so cool. Is there a way that nitrogenases could work in this textile formulation?
Speaker 1:Wow. So first of all, you named the name. Had you not said Amy Grunden's name, I would have said it myself. So Amy Grundon and Kim Hunter are working on the nitrogenase as part of our biocatalyst interactions with gases. Collaboration, big, big collaboration. So, yeah, we have a big collaboration working on big ideas. This collaboration is funded by the Nova Nordisk Foundation. We are very grateful for that support. They've been really wonderful.
Speaker 1:We brought nitrogenase into the project. The collaboration is led by me here through NC State University. We are collaborating with the Danish Technical University, dtu. I have a couple of amazing faculty joining us there and from the collaboration and the folks who are working on the project, we had an early ideation about what we were going to work on.
Speaker 1:And nitrogenase was on the list because the Haber-Bosch process by itself, like this chemical process that makes fertilizer that is critical for agriculture on a planet with a growing population. The Haber-Bosch process itself alone is responsible for 2% of the world's CO2 emissions. So if you could find some alternative to the Haber-Bosch process, that would be a very radical help to reducing CO2 emissions, as well as helping have additional ways that you could bring critical nitrogen into the biosphere, like nitrogen gas, the nitrogen in the proteins in our bodies that make us what we are came from the nitrogen gas in the atmosphere and it came through this enzyme called nitrogenase. It is a monster and you should have a podcast with Amy Grendon and she can tell you how much of a monster it is. But the idea would be the same that if we can get this monster made and she's working on it we could also immobilize it on surfaces. There, textiles might be the right surface, maybe a different kind of coated textile, or maybe even just more flat or a mesh kind of surface.
Speaker 1:The trick about nitrogenase is it is a redox enzyme. It carries out oxidation reduction reactions. It is carrying out a reduction reaction when it converts nitrogen gas N2 gas into ammonia, nh3. So you need to basically bring electrons and protons and add them to nitrogen gas. That's what this amazing enzyme does. So not just immobilizing the enzyme on the surface, but you actually need to have a surface that will deliver electrons and a source of protons to the enzyme's active site. That's the dream. We're working on it.
Speaker 2:My favorite way of describing nitrogenase comes from the PDB, when they did a molecule of the month for nitrogenase and they call it an anvil.
Speaker 1:Okay, I think it's exactly right.
Speaker 2:It's a pretty good teaser point to leave it, but is there any possibility here of conducting so? You need to have some sort of conductive thread in the textile to deliver electrons and hope it's delivered to the right side of the enzyme.
Speaker 1:That's totally believable, because people are working on smart textiles today, because actually in a completely like non, no enzymes involved here. But wouldn't it be great if the kinetic energy from you jogging could power your smart watch? Couldn't you just plug in your smart watch or your earphones to your textiles people are actively working on? It's called smart textiles, and you need conductive materials in the polymers or in the textile structure to do that, and you need to be able to wash them too.
Speaker 2:Very exciting. That's perfect, All right. So we've taken the world's most ideal enzyme we're up there which is carbonic hydrates. I think we've explored it really well, Taken probably, I would say some, and Amy might agree that nitrogenase is probably one of the world's hardest enzymes to engineer, and I think we've just touched on that. I am going to be very sad to throttle this and move this to the last four questions that we'd always we ask all our guests and before going in there, Sonia. This has been such a pleasure, so thank you. Thank you for joining us today. Here's the first question what is a single book, paper, art piece or idea that blew your mind and shaped your development as a scientist?
Speaker 1:That blew my mind. Oh golly, I'm going to give you two answers. I'm sorry it's not single One. Honestly, the late great Carl Sagan. I watched his programs as a young person and when you talk about billions and billions of years, or billions and billions of light years, and you turn the universe into something magical, like he did, that, I can't not think that influenced the way I think, because I think about molecules. When I look at a cotton fiber, I'm thinking about cellulose. So I attribute that to Carl Sagan. Thank you to him.
Speaker 1:The other I'm going to give a big nod to one of my, my first manager. When I got my job at Nova Zymes, we were in North Carolina the company is headquartered in Denmark and his advice was, he said pick up the phone. Pick up the phone, you got to call. They're not going to call you necessarily. You got to be the one to call. That was amazing wisdom and one that I share with every single student who comes through my door. You are the one who must reach out and you have to think about it and you have to do it deliberately.
Speaker 2:So the fun thing that you just did there is that you actually preempted the second question. So, first question yeah, what's the single book thing that blew your mind? Carl Sagan. Perfect answer, and I share a lot of that. The second question is yeah, what's the best advice line that a mentor has given you? And it sounds like that's exactly what the answer is that pick up the phone.
Speaker 1:That was definitely a good one. I've had some other. Another one was don't mess up.
Speaker 2:Really I thought mentors told me to mess up.
Speaker 1:It was given to me in a good. It was a. It came at the right time. Yeah, it was. It's related to people interactions. You don't want to mess up with people interactions.
Speaker 2:Oh, you need to you really.
Speaker 1:You need to appreciate other human beings. We are all human beings. We all have our. We live in our own little worlds. We're all people with lives and exaltations and tragedies, and it happens to everybody and you don't know when it's happening. And you'd be alert and be thoughtful when you're. When something's not going right and you're ready to blame somebody for it, go sleep on it. Think about it before you say something stupid.
Speaker 2:Oh, I like that. It's almost like mess up in the lab, but don't mess up with people.
Speaker 1:Yeah, yeah, that's good, that's a good way to say it, yeah.
Speaker 2:Cool, all right. Question three If you had a magic wand to get more attention or resources into any one part of bio, what would it be?
Speaker 1:That is such a hard question, but I'm just going to say there's too many CO2 emissions going into the air right now. Biology can help us. Anything that can go to support biology in helping reduce our CO2 accumulation in the atmosphere is really critical right now. We need to do that.
Speaker 2:Agreed. And the fourth question is what is one aspect of personal development that you think biotechnologists need to spend more time on?
Speaker 1:Wow. Believing in yourself, believe in you, believe in the person or the people who support you, believe in what you're doing. I could have given up many times. What I'm doing in principle is foolish. Like me, like this girl who sewed little jackets for her horses when she was young. Why do I think I can do something about carbon emissions? Because I can and I'm going to, because somebody has to, and it's me and a whole bunch of other people believing that there's something to be done about this that will make it happen.
Speaker 2:Very rare that I'm speechless. I agree, I love it. So on that note, Sonia, it's always such a pleasure. Every time I leave our conversations I always feel like I've leveled up in three new areas I didn't even know to start getting excited about. I really appreciate both the candor in your journey, but also just the awesome quality of your work. So where can people find out more about you, your work, your new company? Where would you like to send people's attention?
Speaker 1:Oh my gosh, please come check us out. I have been deliberately trying to make our resources and ourselves available. So, first of all, my research team is called Textile Biocatalysis Research. You won't have a hard time finding us on Google. Those three words don't go together a whole lot Textile biocatalysis research. You will find my website at NC State University. You will also find our YouTube channel where we have put out videos of a carbonic anhydrase assay that you too can do in your backyard. A higher tech version that if you have a spectrophotometer with an auto injector you can use it, and the esterase assay that if you can't do either of those, you can do this surrogate assay. And then you can come and see our biocatalysis interactions with gases collaboration website. That is ooh. Maybe I can look it up real quick. It is called biocatncsuedu.
Speaker 2:Perfect, Professor Sonja Salmon. It's such a pleasure. Thank you very much.
Speaker 1:Thanks Dan, Thank you so much.
Speaker 2:Thank you so much for tuning into this episode of the Climate Biotech Podcast. We hope this has been educational, inspirational and fun for you as you navigate your own journey and bring the best of biotech into planetary scale solutions. We'll be back with another one soon and in the meantime, stay in touch with Homeworld Collective on LinkedIn, twitter or Blue Sky. Links are all in the show notes. Huge thanks for our producer, dave Clark, and operations lead, paul Himmelstein, for making these episodes happen.