Tammy Hsu and Michelle Zhu are the cofounders of Huue.
Their problem is this: how do you get bacteria to produce indigo dye? And how do you do it cheaply and reliably enough to replace the toxic petrochemical process that's currently used to dye billions of pairs of jeans a year?
They're working with denim brands to commercialize their bacteria-produced dye.
Pushkin.
There's this idea people have been waving their hands about for a while. Now, what if we're about to have a huge wave of technological progress in biology. On a few recent episodes of this show, we've talked about one obvious place we'd see that wave in medicine, with things like new drugs and human tissues grown in the lab. But the impact could be much broader than that. There's this whole nascent industry called synthetic biology. People are trying to genetically engineer yeast and bacteria to produce everything from fertilizer to fragrances. Take, for example, indigo colored dye, the dye used on billions of pairs of genes a year. That's j E, A N S, not ge nes, unfortunate hominem in this context today, that in goo colored dye typically comes from petrochemicals, and it's made in a process with lots of nasty byproducts. But what if you could use bacteria to make industrial quantities of that dye and get rid of all the nasty by products. I'm Jacob Goldstein and this is What's Your Problem the show where I talk to people who are trying to make technological progress. My guests today are Tammy Sue and Michelle Jude. They are the co founders of a company called Hugh hu u Me. Michelle is the CEO and Tammy is the CSO Chief Scientific Officer. Their problem is this, how can you get bacteria to produce indigo dye? And how can you do it cheaply and reliably enough to replace the dye made from petrochemicals.
To start.
I asked Michelle and Tammy how they arrived at their problem. As it turns out, they discovered the problem from very different directions.
Shell answered first, So, my family, you know, we're immigrants from China, came here to you know, move to la when I was three years old, and that's when my parents actually started their own kind of traditional, you know, wholesale apparel business. So I really, I would say, I grew up in this like fashion and apparel business, but not in a very glamorous way. My experiences or or recollections of the fashion industry. Growing up in this family business was literally you know, traveling with my parents in family vacations back to China over the summers and visiting these mills or garment factories and really firsthand witnessing some of the the negative impacts right of apparel manufacturing and specifically you know, my parents their business was a they were doing streetwear right in the nineties, and so Denham was like a big part of that. And so you know it was specifically denim mills and and denim manufacturing.
And so what did you see, like specifically when when you mentioned that you saw saw that side of the industry, Like, is there a particular trip or a particular thing that you saw that that stands out in your memory.
Yeah, I mean I think about you know, going to the kind of literally like you know, textile manufacturing cities right in southern China where it's just like, you know, a bunch of kind of conglomertive factories all you know, all together. The air quality kind of outside isn't great. You go into the facility, it's even worse. Everybody has kind of masks on. There are basically like blue particles.
In the air.
You know, it's just on people's skins, you know. And I was a child right at this time, but those are the kind of like images that are I think still ingrained in my mind. I Mean, the dye industry is a key kind of a fender, I would say in terms of, like, you know, jobs that pose threats to safety, both in terms of worker health as well as community health. You know, dying and the effluence from dying, you know, is a major source of water and kind of community pollution. Right. And by the way, you know, in the indigo process for example, right, specifically, you've got you know, not just analine, which is a benzene derivative, right that has true carcinogenic properties, but you've got you know, sodamide and formaldehyde and you know, these harsh chemicals that are going into the production process of these core dyes have done a lot of innovation in the fashion industry, but the kind of dye space itself hasn't seen a whole lot of innovation.
Good. So that's your introduction to denim really early. The seed is planted, right, yeah, Tammy, how do how do you come into the story?
So my story and background is very different from Michelle's. And so when I was in college, I was introduced to this field of synthetic biology, which is how do we take these microbes you know, e. Coli or yeast and actually program them to make them produce useful chemicals for for people.
So you're in you go to grad school, you go to get a PhD in Berkeley, and you find yourself in a lab. What's what's the sort of generally what's the lab working on?
Yeah, so the lab I was in was working on how do we develop tools for engineering E. Coli and yeast microbes to produce things like drug precursors or colors or kind of other biochemicals.
Get microbes to make useful stuff for people exactly exactly? And how do you land on indigo?
Yeah, there was there was this idea kind of floating around the lab right before I joined, about how do we produce indigo? Actually, I think it was because people wanted to be able to see what was going on inside the cells. Cells are really tiny, right, and often you make these changes and you try to get the enzymes to do different things, but you don't really know exactly what's going on without doing some complicated assay. So there was an idea that maybe we could use a color output, Like we change an enzyme and we get this color output, and indigo is kind of this natural diet's found and plants, so they were like, maybe we could use indigo to see what's kind of going on in the cell.
So just to be clear. So just to be clear, the idea of getting a cell to express indigo this blue color. The idea wasn't oh, let's make clean or dye for blue jens. It's let's make a tool for scientists to use to understand what's going on inside the cell.
Initially, yeah, and then as we were kind of looking into it, it actually seemed like indigo itself was a really big problem in the textile industry. Pretty much all indigos used for dnim genes and it we learned that all of it, the vast majority of it, is sourced from petrochemical sources right now, and so there was this need to actually make it in a biologically sourced manner. My advisor was on this fellowship and they published an article showing some very preliminary results that we were having in the lab on this project, and it was published on the UC Berkeley website, and then Dune and brands in the area actually started to reach out to him and say, oh, I heard you're working on other ways to make indigo. Can we talk what is it like? How much you know? Can we do a little trial, so.
You decide to start the company. Tammy, you've done this research, Like, what exactly had you already done? What did you know how to do when you started the company.
So at the end of my PhD, the last figure in the paper that we published was actually kind of unusual for a research paper. I had died one piece of fabric. It was a scarf with this indigo die. It was definitely died in a way that was not scalable and not industrially viable by any means.
It smelled a little bit funky.
How how was it died? Like, how did you how did you diet?
I actually hung up a shoelace across across the hallway and just kind of flopped this piece of fabric over it, and I sprayed the dye against it and used the bucket to catch the remaining dye at the bottom. It was definitely an experience, but we at the end of the day we got this nice blue fabric and it was kind of our first proof of concept.
So it worked. It worked at least for one scarf, one time in the hallway, at least once exactly good.
I want to clarify that even though it turned blue that before. Right, we were literally telling the story yesterday to the company. It was like that was like, okay, blue is great. We had no idea you know, oh it's kind of blue greenish, or like you know what exactly all of that means. We had no capability to measure or understand any of that. So really getting it to those industrial specs, I would say, was probably the first major challenge that the company that we as a team had to tackle.
So tell me about that, right, Like, blue isn't good enough? Right, you can't go to some genes manufacturer's going to make one hundred thousand pairs of genes be like yeah, it's blue. They're not gonna be like great, send it to us, right, so what do you have to do to get it to be the right kind of blue?
So kind of where where we were at when at this first proof of concept was okay, so you have cells. They're making this indigo molecule. We know it's literally indigo molecule. The cells are growing in their own media. We just try to like you know, break open the cells and try to you know, get the blue onto the fabric.
But that's not necessarily good enough, right, so you've.
Got the right molecule, what do you have to what do you have to fix when you're you know, starting the company, leaving academia, going to make this industrial product. What do you have to fix on the kind of molecular level.
I think the main thing is how do we separate out the indigo molecule away from all of the other things, all of the cells and all of the things that the cell is growing in. And so at the very beginning, a lot of our methods were very rudimentary, using you know, some off the shelf chemical engineering ways, and so that's why our first dye turned out a little bit green. And that's why kind of our first first hire was in a downstream processing engineer so that he could help us fix this problem.
So the problem is, how do you get rid of everything that is not the indigo dye molecule, all the cells that made it, all the stuff that the cells were grown. You got to get rid of all that, but keep the dye. That's the first hard problem, exactly exactly.
And then kind of pairing that, I think the other key unlock for us was also bringing in actual textile technical expertise, so no longer are we doing a visual test of is it blue or not? But now we can actually precisely quantify how green is it, how red is it relative to the amount of blue, and how close is that literally numerically compared to the synthetic standard that we want to be match up.
So there's figuring it out at that level, and then there's figuring out how to make thousands of pounds of this die, right, which seems like a related but distinct problem that you've got to be solving sort of at the same time.
Yeah, exactly.
So you know, like when Dunham Brands came a knocking, They're like, can you make a kilogram?
I was like, absolutely not.
And so one of the big limitations thus far in this field of synthetic biology is, Okay, so you can grow your microbe, you can grow it at larger scale, but how do we actually get the space to produce this at a large industrial scale over and over in a really repeatable way.
And so for that you need really large scale equipment.
How do you truly industrialized how do you make lots and lots of dye every day in a factory? For us?
Exactly?
And I think even that we with the growth of the synthetic biology industry, there's been a lot more demand and building out of these contract manufacturers where we can we don't have to build our own facility. We can kind of drop into an outsource facility and be able to make use of that infrastructure.
Tammy and our team have now reached the point where they can in fact make not just one kilogram of dye, but hundreds of kilograms. Progress after the break, what they still have to figure out to get their die out into the real world. That's the end of the ads.
Now we're going back to the show.
So maybe for Michelle, Michelle, can you tell me just where's the company now? What are you making now? And like what can you not do yet that you need to do?
M So, so maybe just taking a step back, I would say, you know, from back then when Tammy thought one killogram was too much, you know, I think we've really been able to step up in production every year as we've also refined and iterated on the process and the product. So you know, have gone from making just a couple of grams to a couple killograms to now, you know, hundreds of kilograms, and we have an eye towards you know, metric tons, so thousands of kilograms, so that we can actually meet the industry in these needs, right, which is the tens of thousands of metric tons kind of level.
And so when do you think you'll be able to make at a big enough scale that you can actually sell it to somebody who's going to make g means for me and the world.
Yeah, well, so we are. We have been testing and trialing our product to make sure that we're approving kind of the iterations of the product and designing something that is truly drop in and usable for the denim industry. We are already working with brands that you know, I think listeners, you know and love.
Can you say the name? Can you say one name of one brand?
We cannot share the name uncorriginately.
Okay, when do you think I can buy a pair of genes? Died with your die?
So I'm not going to make any promises, but I would say, you know, in the next couple years.
For sure, you just made a promise. I'll take it.
You're right, that's true? Cut out the foresure. Yeah, No, I mean just to say, I think you know we are in you know, we're working collaboratively with the brands, and it's really a matter of our own capacity and scaling and then kind of bringing the cost down over time too, so that it can be something that continues to be more and more accessible to the broader fashion industry.
So let's talk about the cost. Yeah, tell me about the economics of it.
I mean, it's it's one of the big goals of the business to make it write a success. You know, I would say, we're definitely not there yet right to your point, you know, probably and you know, order of magnitude of productivity away. In order to get there, you.
Think it needs to be the same price as petrochemical dies.
So what I would say on the kind of price side is I think we're making a bet that brands in the greater supply chain understand the big picture here and the opportunity is that, you know, luckily dies they can make this huge visual impact, but again they're only actually a very tiny fraction of what makes the garment itself. And so we believe there's a path to commercializing early even before we are cost neutral with the petrochemicals. But we can commercialize early to help build the business before we're there. At the cost side, because it just doesn't make a huge difference on the end price of the garment for example. Well as an example, it's like, are you willing to pay five dollars more for a pair of genes to help to facilitate that transition of the industry to better materials before it becomes cost neutral?
And just to be clear, like five dollars more is when your die is how much more expensive that petrochemical based die.
Five dollars more is like is like ten x more expensive chemical die.
The die The die cost is a very small percentage of the overall cost of a paragenes exactly. Okay, So presumably there's like the sort of classic early adopter curve where there's a universe of people willing to pay more because they care or because they want to signal to people that they care whether they care or not. And those people will be your early adopters who will allow you to scale, and then you'll use that scale to become a cost neutral. That's the dream.
Yeah, I think so, I think we think about, you know, the Tesla model for this right where you see.
Everybody loves the Tesla. Everybody, everybody who's not making software everybody who's making a physical thing.
It is.
It is really remarkable how that metaphor is the It's like it used to the uber but for X, but now it's Tesla. But literally yesterday I was talking to a guy who's doing that with houses. He's building these little backyard houses. Cover. The companies called Cover and they're building like really nice little backyard studio apartments. But they want to build houses and they want them to be cheaper, and it's a Tesla metaphor.
It's like you go to the premium and you go down and it worked.
And it worked for them. They did it. Are you working on other colors?
You know, there's a broader platform and kind of opportunity here right to not just you know, disrupt denim, but also the fashion industry and food and cosmetics in all of these areas where color is infused into our daily lives. And so we're actually now taking our learnings from you know, bioengineering our first color product and looking at the broader kind of platform that we've developed and saying, how can we also create a broader palette that isn't kind of one color at a time, knowing that there are tens of thousands of different colors in use in these variety of industries today.
Uh huh. Build a system that is more easily customizable so that you can get the cells to make whatever is the color of the season.
That's right.
In a minute, the lightning round with lots of questions about genes and genes as in denim. Now back to the show. Let's let's do a lightning round. Let me just ask you a bunch of questions before it's time to go. Oh gosh, Okay, they'll be different, they'll be simpler and more fun. Okay for either of you. Why are genes still almost always blue?
Because I don't know if this is a very chicken and egg answer, but it's because it has to be made with indigo, and I think an indigo is blue. And indigo actually binds the yarns in such a way that you can kind of flake it off from the from the fabric, and you know, as you wear it, it takes the shape of you know, your body or you know, the wallet that you put in your back pocket. And it's really rare to have a dye that has these properties.
I've seen numbers that seem wild for the number of jeans made in a year? Do you does either you know a true number for that?
So our latest estimates are number of gens every year made is about two to four billion garments.
Billion, Like that's billion. That's wild, right, Like yes, I mean what are we at for the world?
Now?
Eight billion people?
Is that? Is that right?
So it's like in a few years you have a pair of genes for every single man, woman, and child on earth.
Yeah, exactly.
Okay, here's one for both of you. And I want you to try and answer at the same time. So I'm gonna ask the question and then I'm gonna say one, two, three, and then when I get to three, I want you to just give a yes or no answer. Can you wear a jean jacket with jeans? Yes?
Or no?
One?
Two three?
Yes? Oh, it's coming back. It's a trend that is coming back. Now, I'm telling.
You that may be true. That may be true.
Michelle, you came to hear from the business world. What do you know about science now that you didn't know when you started the company?
Ooh, too much? I know. I know so much about science. I know enough to be dangerous to talk about by engineering and chemical engineering. And you know the bio manufacturing to be to be really dangerous. So just to say, you know, I think there's a lot of great science, a lot of great ideas out there, but actually, you know, I have a lot of respect for the chemical engineers and the folks who actually go from R and D to actually turn it into something that has a commercial case around it. And you know, we need to make those tough decisions and work on those optimization problems to actually get it to be something that's adaptable for the industry.
So I just want to shout out your dog, who's really doing amazing work back over your shoulder. What kind of dog is it?
She's a Congress Spaniel. This is one of her better days. She really loves showing her just just all sides of her. Let's say to the camera whenever I am on.
Camera, what's her name? Her name's Daisy, Daisy Classic. Michelle Zou and Tammy Sue are the co founders of Hugh. Today's show was produced by Edith Russello. It was edited by Sarah Nix and Robert Smith and engineered by Amanda k Wong. I'm Jacob Goldstein. You can find me on Twitter at Jacob Goldstein, or you can email us at problem at Cushkin dot fm. We'll be back next week with another episode of What's Your Problem.