UC Science Radio: Season 2 Episode 2 transcript

Flynn Adcock: Bioplastics from bacteria

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Molly Magid: Welcome to UC Science Radio, where we interview a range of postgrad students to tune into the fresh voices entering the world of science and learn what sparked their passion. I’m Molly Magid, a Master’s student in the School of Biological Sciences.

Today I’m talking with Flynn Adcock. He's a Master's student studying microbiology. His research is about bacteria that can convert methane gas to biodegradable plastic. He's also the winner of this year's Three-Minute Thesis competition and will represent UC at the national competition.

Molly Magid: Kia ora Flynn, welcome to UC Science Radio.
Flynn Adcock:
Kia ora Molly, how are you?

Doing well, how are you?
I'm great, thank you.

So, you're studying microbiology, but specifically, what's your research about?
I'm studying a particular type of interaction between two different types of bacteria—ones that degrade methane and ones that accumulate a particular molecule that we can use to make biodegradable plastics. It's a very lab-based research process where I'm cultivating these bacteria in different flasks and in different conditions to see whether or not those conditions influence how they grow, how they interact, and what they produce.

Why are you growing it in the first place, what's the point?
The whole idea is that my thesis contributes to a large research project. This project is with a Crown Research Institute called Scion and we have this collective idea that we can essentially take (away) methane gas, which is a greenhouse gas in the atmosphere, it’s very potent and bad for the atmosphere. And our hypothesis is that we can essentially take this gas and put it into a bioreactor system and have our bacteria eat this gas to degrade it and in the process make that biodegradable plastic. So, what we really want to do is tackle a larger problem—being climate change from anthropogenic gases—and try and reduce that somewhat by creating a biodegradable plastic as well as degrading that gas.

What is a bioreactor?
Great question. Essentially a bioreactor is a tank, if I reduce this down to its main components, it's just a tank with media or liquid to grow your bacteria, something they're comfortable with. You have two inputs—one would be the gas coming in and the other would be the culture or the liquid or the bacteria coming out. Essentially, just think of a tank with two different components in it.

How are they making the plastic and then how do you extract it, how do you use it?
That first type of bacteria is that methane-degrading one. What they do when they eat this methane is that there's a bunch of things that they can't process, and they release this into the bioreactor liquid. In this environment, we introduce a second bacteria called purple non-sulphur bacteria. These guys are awesome because they can eat all that stuff that that methanotroph, or methane-eating bacteria can't. In this process, if you can make the liquid, if you can put the right concentrations and amounts of food in this liquid, you can actually make these purple bacteria accumulate a molecule called PHA, which is essentially a polyester, polyester's a plastic. What we can do is we can extract this culture from the bioreactor and you can spin it down to create, we call them pellets of bacteria, and within those pellets, you have those PHAs. The PHAs are used in the process of creating larger polyester molecules that can then be used to make biodegradable plastics, such as biodegradable water bottles, or it's being used to make surgical mesh and other things.

Is a lot of your work in the lab just setting these conditions up to see what works the best?
You have to go back and do earlier preliminary tests. So you have your bug, your bacteria, and see how well it grows on the media you put into this bioreactor. That’s where I come in, I’m going to be testing this range it grows on.

There's also another avenue of my research which is finding a bacteria that does both processes. And so we're gonna be going out and bioprospecting in Rotorua, in the Rotokawa region. We'll be looking at particular environmental conditions in which we'd find this bacteria, and taking samples and putting them in the lab and seeing if we can find a bacteria that does both. In theory this bacteria exists, but it's never been found on the planet. So if you can find it, then that would even be quite world-changing.

How do you go about bioprospecting? I'm guessing that means just going out and trying to look for this bacteria can complete a process that you want?
Yeah that's right, with all the different types of bacteria, there are so many different kinds of metabolic pathways. With humans, you often see in science classes, we take sugar, we make energy. Well with bacteria, they can take methane and make energy. So the idea of finding one bacteria that eats methane and accumulates that bioplastic and can do it for a small amount of resources, of time and energy, which will change the world. Because you'd find that this type of metabolism has never been described before, it's never been in the literature.

What you do is you target areas such as deep lake sediments or hot springs or geothermal areas, places where you find there is methane, but all of a sudden, in that water column there's no methane. How is it disappearing? Where is it going? Perhaps there's a bacteria there that's doing that process.

One of the big things in this research and with bioreactors and cultivation in the lab is that you need light in order to make the process really efficient with the purple bacteria, that's why they're purple, because they use light when they're doing their reactions. But they use a special kind of light, they use infrared light—which is longer wavelengths of light. And where do you find longer wavelengths of light in the environment? Well, you find them deep down in water columns where they can penetrate, because normal light diffracts. So if you were to (take a) sample in an area that has little methane all of a sudden and low wavelengths of light, and replicate those environmental conditions in the lab, perhaps you could grow that bacteria that can do both of those processes. IR light can be really cheap to run with LEDs. A good thing when it comes to upscaling the bioreactor, when you're doing the pilot studies, is that you have this IR light which is cheap to run. You shine it inside that bioreactor onto the single bacterium that does both the processes— eats the methane, gets that PHA nutrient to make the bioplastic, all in one step.

Where would this get applied?
That's a great question. I guess, with the early preliminary testing where I'm having a look at the interaction of the bacteria and the culture conditions, Scion would be doing the bioreactor set up, that's their expertise or their specialty. They manage the application of these bioreactors and look at the opportunities where we could install them or where we could work. But yeah, obviously you have to have those pilot studies so it could be years down the track before we see this technology implemented because it is in its infancy.

In any case, you could install these bioreactors into places that have point-source release of methane, so that could be places like in rubbish dumps. That's a massive one, there's so much methane coming out of the rubbish dumps. You could have them in wastewater treatment facilities and even for oil and gas extraction. So it doesn't have to be limited to New Zealand, this bioreactor could be retrofitted anywhere in the world.

What inspired you to do the three minute thesis?
Oh the Three Minute Thesis, what a competition. Well I really like public speaking, I really wanted to hone my scientific communication skills because they are incredibly important. We often take for granted the vernacular associated with biology.

For instance, I gave my thesis in three minute talk to my flatmates and one of them said: "It was pretty good but I didn't understand some of the terminology." And I said: "Oh that's cool, well what's this terminology you don't understand." And they said: "Oh something ‘M,’ , ‘M’ something." And I was like: "Ok, was it methanotroph?" And they said: "No, no you explained that. What was the other thing?" And I was thinking to myself, what could it be? And I said "Metabolites?" And she went, "Yeah, yeah that's the one—metabolite! I didn't understand metabolites." And I was like, wow, I took it for granted that as a word that's commonly thrown about in biology, you know you have to take a step back. How can I make this information, this complex idea more accessible to a general audience or the public?

Alright so my last question is: right now, you're just at the beginning of your master's research, but that means it's time to dream big. If you could see one big change in the world come out of your research, what would that be?
Ah man, so if everything was to work perfectly, it would be awesome to see small pilot scales done of this remediation technology in the next couple of years and even implementation of these bioreactors throughout New Zealand, and perhaps even worldwide.

Thank you so much for talking with me, Flynn.
Yeah thanks for having me, it was awesome!

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