Living Science
How Waste Becomes a Resource
Using fermentation and genomics, Victor Ujor helps microorganisms turn what's useless into something useful.
Victor Ujor’s fascination with microorganisms — bacteria, fungi, viruses — began with an issue of Time magazine. What he encountered in the pages of that publication, combined with a passion for the life sciences and a distaste for hospitals, made him bypass possible careers as a lawyer or a doctor. Instead, he chose to pursue microbiology.
A native of Enugu, a city of more than a million people in Nigeria, Ujor studied microbiology and fermentation at his hometown university, where he dabbled in home brewing to gain a deeper understanding of the microorganisms he loves. He then earned master’s and doctoral degrees at the University of Westminster in London.
Now, as an assistant professor in the Department of Food Science, Ujor leads a campus lab that studies how microbiological tools, such as molecular engineering and natural fermentation biology, can convert waste products into biofuels, renewable chemicals, and sustainable materials. His main goal is to use these processes to help solve the world’s ecological challenges, from climate change to population growth.
What about microorganisms fascinates you? And how did your fascination originate?
Just about everything. One day, late in high school, I went to a relative’s house, and she gave me an issue of Time magazine, where Dr. David Ho was named Man of the Year. He had come up with a new treatment for HIV using special inhibitors that prevent the virus from penetrating T cells. And there were scientific stories talking about what people could do in immunotherapy using microorganisms. I started thinking about these little bugs that mostly we can’t see with our eyes, how they can really affect us, how they can benefit us.
And then I had the opportunity to go to a scientific lab, where someone allowed me to look through the microscope. You look at the slide, there’s nothing; then you place it and look through the microscope, and everything becomes colorful, beautiful.
So, I kept wondering about how they do what they do, how we can contribute to society through them. I fell in love with studying them. And I never fell out of love with them, just trying to figure out how we can get microorganisms to do what we want rather than what might hurt us.
And those experiences led you to your undergraduate university?
Yes, I went to the Enugu State University of Science and Technology, where I studied microbiology and brewing science. What a beautiful combination. I was just trying to learn more and more and more; and as I did, I realized I liked the applied aspect of it, manipulating microorganisms, growing them to produce something.
And I recall brewing beer for the first time from scratch. I actually malted my own grains at home, and my brothers watched. I finished brewing the beer three or four days later, and they said, “We’re not going to drink it with you because we’re not sure what you’ve cooked up. But if you are alive by tomorrow, then we’ll help you finish it.” It tasted good, and the next morning, when I woke up, they said, “All right, let’s go try some beer.”
What got you thinking about using microorganisms as tools for solving problems like climate change, population growth, and waste generation?
I think that started when I was wrapping up my bachelor’s degree. I studied bacteria that breakdown crude oil and, in doing so, I read about the massive Exxon Valdez oil spill in Alaska [in 1989]. It made me wonder how we could find a way to meet our energy needs without leaving us prone to such a disaster. Then I went to graduate school in London. That’s where I realized that biofuels were becoming something really big. And not just fuels: We refine oil into about 6,000 different chemical compounds, and the vast majority of them are so crucial to the economy that we cannot live without them.
And that spurred more interest in the role of microorganisms. I was doing a massive project on extracting antibiotic compounds from fungi. We found that the fungi made a different set of compounds depending on the conditions you grow them in and the nutrients you feed them. I realized, if you can keep fine-tuning the conditions, you can get a wide array of chemicals, and a good number of them can have applications.
You’ve described the focus of your research as using microbial fermentation and synthetic biology to develop new ways to convert organic wastes, pollutants, and agricultural residues into value-added products. Let’s talk more about that.
Often, with fermentation, we think of cheese, beer, and wine. But there’s a lot more to it. You can grow microorganisms under the same or similar conditions used to ferment [those food products], but you get a different set of products. For example, you can grow microorganisms and produce something like butanol, which is used to make paint and synthetic rubber.
The beauty of it is that, with genomics today, we can understand what different organisms are doing at the molecular level. And we can bring together the traits of different organisms to make new, useful compounds.
Why is it important to explore this?
There’s water scarcity in different parts of the world, more than ever before, and our population is growing. We can’t run from it. If we’re going to be sustainable and actually thrive on this planet, we have to find ways to use most of the resources available to us. And waste is something we generate a whole lot of. We have to start thinking of waste as a resource.
That’s what my research is trying to do. We can take excess plant materials, like wheat straw, extra corn stover, forest residues, and then extract sugars from them. And we can feed those sugars to the microorganisms during fermentation to make different [potentially useful] compounds. Then we sort of coax them to make more. Examples of these compounds of interest are 2, 3-butanediol [used in the manufacture of fuel additives, foodstuffs, pharmaceuticals, and more] and 1, 3-propanediol [a common solvent, also used to make adhesives, composite materials, and laminates, among other things].
Can you give us an example of a potential practical application you’re studying?
We’re looking at societal waste that is extremely difficult to manage. For example, there’s a process called anaerobic digestion. We use it to treat waste, things like animal manure. You put it in a big tank and naturally present bacteria break down any residual carbon to produce methane, a natural gas you can use to generate electricity. So, that’s a very wonderful process. But at the end of the day, there’s yucky stuff that comes out of that — it’s full of phosphorus, ammonia, and you need to find a place to safely put it. Maybe you can use it on farms for fertilizer, but there aren’t enough farms that want it. And transporting it with trucks introduces carbon dioxide into the atmosphere, which is not very eco-friendly.
So, we figured out that we can actually harness the power of this waste to make different compounds by just introducing them at different concentrations in our fermentation process. One of our studies showed that the microorganisms pull out most of the phosphate, the ammonia, the light metals, heavy metals, the sulfate, the chloride. Close to 50% of the minerals were reduced significantly.
That sounds very promising. Are there other possibilities you hope to pursue in this area?
We are mainly looking at anaerobic digestion as a process to make different compounds from waste. Hopefully we can scale it at some point so waste can serve as a reliable source of minerals for fermentation. And hopefully we can make the process more sustainable.
Next, if we can prove what we’re doing with anaerobic digestion, we’d like to extend it to a much harder-to-treat waste, such as landfill leachate [chemicals drawn out of landfills when rainwater filters through the waste]. Leachate is also full of minerals.
If we can find more ways to mine organic waste as sources of minerals, minerals that microorganisms can use at different concentrations as ways to make valuable compounds, we can reduce the cost of the minerals and hopefully compete more efficiently with crude oil–derived chemicals, in terms of cost.
⊕ Online Extra: Further Reading
To learn more about how microbiological tools can convert waste into valuable products, check out these studies coauthored by Victor Ujor.
“Whole-genome Sequence and Fermentation Characteristics of Enterobacter hormaechei UW0SKVC1: A Promising Candidate for Detoxification of Lignocellulosic Biomass Hydrolysates and Production of Value-Added Chemicals,” by Santosh Kumar, Eric Agyeman-Duah, and Victor Ujor, in Bioengineering (September 2023)
“Ribozyme-mediated Downregulation Uncovers DNA Integrity Scanning Protein A (DisA) as a Solventogenesis Determinant in Clostridium beijerinckii,” by Victor Ujor, Lien B. Lai, Christopher Chukwudi Okonkwo, and Venkat Gopalan, in Frontiers in Bioenergy and Biotechnology (June 2021)
“Chromosomal Integration of Aldo-keto-reductase and Short-chain Dehydrogenase/Reductase Genes in Clostridium beijerinckii NCIMB 8052 Enhanced Tolerance to Lignocellulose-derived Microbial Inhibitory Compounds,” by Christopher Chukwudi Okonkwo, Victor Ujor, and Thaddeus Chukwuemeka Ezeji, in Scientific Reports (May 2019)
This article was posted in Basic Science, Bioenergy and Bioproducts, Changing Climate, Economic and Community Development, Healthy Ecosystems and tagged anaerobic digestion, Fermentation, Food science, microorganism, synthetic biology, Victor Ujor, waste.