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SCRIPT:
Alex: "Yeah, so this is an old garbage dump."
That’s Alex Tøsdal Tveit - a microbiologist at the Arctic University of Norway in Tromsø, a rugged Arctic town where reindeer roam the streets it’s often called the gateway to the north.
Behind him, the Arctic Cathedral’s bells ring out across fjords and snow-capped mountains.
So with all this beauty why’s he hanging out at a dump?
Because it’s leaking methane - a powerful greenhouse gas.
And what he and his colleagues found in a single scoop of soil here could change the way we fight climate change.
Alex: "So the reason why this soil is so important is that it contains a small number of microbes that consume methane directly from the air. This was a group of microbes that had been hunted for a couple of decades already. And, by chance, we got one of them into the lab in Tromsø."
A lucky break, a tiny organism and a big promise: bacteria that can live on air and pull methane out of the atmosphere.
My name is Neil King and this is Living Planet – the show that brings you one surprising, thoughtful story about people and the planet – every week. And today’s episode is about a lucky discovery that could help us tackle one of the most dangerous greenhouse gases on Earth.
Now, to understand why this discovery could be so important we need a quick recap of the gases fueling the greenhouse effect.
When it comes to climate change we’re pretty used to hearing about that one main villain.
But CO2 has plenty of side kicks.
One of them… is methane.
It’s responsible for about 30% of the rise in global temperatures since the Industrial Revolution, according to the International Energy Agency’s latest Global Methane Tracker report. And it’s becoming a bigger and bigger problem.
Methane is now at its highest rate in the atmosphere than any point in the last 800,000 years of earth’s history.
Alex: " So It's almost tripled since the industrial, revolution. But the real scary part is that the rate of increase is also accelerating."
Alexander Tveit says although there’s way less methane in the atmosphere than carbon dioxide… it’s a much stronger heat trapper - about 80 times more powerful than CO2 over a 20-year period.
But luckily it has a shorter lifetime in the atmosphere than carbon dioxide so…
Lisa: "... on a 100 year scale, it's around, you know, 23, 24 times more heat holding capacity."
That’s Prof Lisa Stein, Head of the Climate Change Microbiology Lab at the University of Alberta in Canada.
She says despite its shorter lifetime methane is having a big impact on our climate especially given how much of it is being produced.
And she also points out these features make it a great target too.
Lisa: "If we can remove methane from the atmosphere and we can limit its emissions. We have an opportunity within the next decade or two to limit the rate of warming. We don't see that with CO2 removal."
So, methane’s a big and growing problem and a good target in the battle against climate change.
But where’s it all coming from?And what’s it got to do with microorganisms?
The latest Global Methane Budget Report shows about two thirds of methane comes from human-related activity, including agriculture, burning fossil fuels… wastewater and landfill….
The rest comes from natural sources like wetlands, or lakes…
And much of it comes from microorganisms naturally breaking down carbon-rich matter for energy.
Which brings us back to Dr Alexander Tveit’s work.
He began his career studying methane production in cold environments.
Alex: " Yes. It, it typically happens in, wetlands or in lakes. And naturally places, where you don't have oxygen is where most of this methane production is taking place."
In places like this bacteria and archaea break down organic matter to release the energy locked inside...
Alex: " Instead of being fully oxidized to CO2, all the energy is not actually extracted as it's broken down by different groups of bacteria in steps. The final step being the production of methane."
But while some microorganisms are producing methane in these environments the scientific community has known for a while there are also others consuming it.
These are called methanotrophs or methane oxidising bacteria.
Alex: " Because methane is such an energy rich substrate, nature is also utilizing it. So there are microbes eating the methane and this balance between methane production and methane consumption. We don't know yet how this is gonna be."
Alex’s lab is one of the key players worldwide examining the dynamic between these two types of microorganisms by closely studying their physiology.
And back in 2008 his colleagues came to this dump to see what might be living here.
Alex’s former supervisor, now Emeritus Professor Mette Svenning and lab technician Anne Grethe Hestnes collected samples from this site mainly for their students…
Alex: "So we have these student courses in microbiology, microbial ecology, and then they had been working on, what we call methane, oxidizing bacteria or methanotroph. So back in 2008, Anne Grethe Hestnes, who is a technician in the, in the lab I'm working in as well. and my former supervisor, Mette Svenning, they decided that would be interesting to take some samples from this landfill site. So Anne Grethe went, it's just over here, a small ditch where she just scooped up some samples."
Anne Grethe is still at the lab. But she wanted Alex to speak on the team’s behalf.
Alex: " So what she does is that she takes this little piece of soil."
As he recounts what happened purely for dramatic effect the Arctic Cathedral’s bells start ringing again.
Alex: " So, she would've taken this, this is like a 50 milliliter, Falcon tube. So she would just put it upside down. So with the opening into the ground, and just dig out the piece of soil. And then lid on. That's it."
And with just one chance twist of a tube his colleague Anne Grethe had scooped up something remarkable.
Alex: " Yeah for me, it has opened up, basically most of my research these days from this, one tube of soil in 2000, 2008."
But they didn’t realise that right away!
Anne Grethe took the scoop back to the lab and used the standard procedure for culturing methanotrophs that were already known to exist in soil.
Alex: " And so you, mix up the soil with this nutrient media, put it in a bottle, and then, then you add methane in the air, in the head space, and you close up the bottle. She got a good growth of a type of, methanotroph in the liquid. And she tried to isolate it. And she, found out that it's, it's growing fast on methane. But then didn't think much more about it. She had problems finding out exactly what kind of bacterium this was."
But she knew it was weird…
Because unlike other microbes that could live off methane in soil this strain was able to live purely off the air and it seemed to be sucking up methane to survive.
So Anne Grethe kept this weird little colony of bacteria alive, stored away in a corner of their labs.
Alex: "So the bacterial culture was just sitting around. one day during lunch, she mentioned to me that she had this bacterial culture growing. That she was not sure exactly what it was. And uh yeh, she wanted me to have a look at it."
So he did…
And they also roped in a visiting student in their lab Serina Robinson to help with the project.
Alex: " So that's when we sort of started to dig."
Together they examined how pure strains of this bacteria grow, what conditions they can survive in, and they looked more closely at its genetic sequence.
They published their findings in 2019 in the Proceedings of the National Academy of Sciences winning the journal’s Cozzarelli Prize in biomedical sciences for that year. Because of what they were able to show.
Alex: "I think the single most special thing about that study was that we could show that we have found that the bacteria can cover all their needs for energy and carbon and even nitrogen from the atmosphere. And so they are able to cover all their needs almost for life, just from air."
Lisa: "I was just floored. I'm like, you've gotta be kidding me. Like I was, it was a very exciting finding for us in the field."
Professor Lisa Stein again…
She says just figuring out how to keep these bacteria alive to prove they exist and to study them was already a huge step.
Lisa: "Cultivation is really difficult work. It takes a lot of time and patience and getting to the point of a pure culture is, a rare accomplishment,. His laboratory has these microbes now in culture, and we can understand how and why they're capable of living on air."
And the closer Alex’s team looked at this bacterial strain, the more excited people like Lisa got.
Because this strain can also comfortably feed off really low methane concentrations, including current atmospheric concentrations today.
Lisa: "So this was a remarkable achievement and it's really, moving the field forward rapidly because we can now think about how we can leverage that physiology and metabolism to build different types of technologies for removing methane from the atmosphere or from high methane emitting sources like a, a rice patty."
Alex’s team proposed to call this strain Methylofortuna gorgona…
Gorgona because under a microscope stingy tentacle-like filaments sticking out of the bacteria resemble the wreathing snake hair of the mythical gorgons.
And Methylofortuna because of their great fortune isolating this bacteria.
Alex: "These cultures they were not designed to culture these bacteria specifically. They were set up with high methane concentrations and,. Who knows, might be in, a strike of luck that she had this particular bacterium growing."
After closer genetic analysis the species name has changed to Methylocapsa gorgona because of its similarity to existing species.
But Alex and his colleagues still consider it a lucky break because it promises to be a fortunate discovery for climate mitigation strategies too.
Which we’ll hear about after this short break….
Promo
So… there are a bunch of microorganisms making methane and it’s building up in the atmosphere, adding to the greenhouse effect and climate change.
But other bacteria also eat methane right out of the air like Methylocapsa gorgona.
So how exactly might this discovery help in the fight to slow the greenhouse effect?
Alex: " I would say like three different lines of research based on this bacteria. One is where we use the insights from the pure cultures to understand how they function in the environment so that you can predict how they will respond to natural changes. Understanding how these cells work at the most detailed level. It's just fundamentally interesting to understand how a sort of important part of the carbon cycle is working."
This helps with better climate predictions but could also help with the second application…
Alex: "Potentially one could reintroduce these bacteria into areas where either human activities have made them go away, or you could introduce them into areas or surfaces where they haven't been living, And maybe even being able to manipulate their function so that they will be able to survive in these areas."
So understand them well enough to help them flourish naturally.
And then the final application is to find a way to kind of supercharge them.
Alex: " We are working with researchers on trying to cultivate them as efficiently as possible in systems that can be used as biofilters, so to filtrate, methane out of the air. The idea that you can grow this bacteria in systems that can be used to, to basically to clean up air."
And many in the wider research community are excited about that potential, including Professor Lisa Stein from the University of Alberta.
Lisa: " So now that we have these microbes in culture and they are growing on methane, we could envision inexpensive passive systems that are working nonstop around the clock. Consuming methane from the atmosphere. This doesn't require much input from us We could build bioreactors. And that's what work that Alex and I have been thinking about over the last couple of years."
But she says it’s not just these two who have been working on this idea of a system that uses these bacteria to pull methane out of the atmosphere and convert it into biomass.
Lisa: " There's a few systems and there is a group out of the United States that is at the point of raising commercial funds for their bioreactor system. So that system is based on what's called thin membrane, the microbes are on a material with a very thin layer of liquid that they can grow on. Very similar to the floating filters that Alex's lab used to cultivate these atmospheric methane oxidizers.
And what Alex and I have been building is bioreactors based on hydrogel material. So these are materials that are like gelatin or agar If we embed the microbes and hydrogels, then they can absorb the methane and the microbes are right there inside the hydrogel, ready to take it up."
These projects are still in their early testing phases. But if they’re shown to work well, there are even some plans about what to do with all those happy cultures of bacteria after they’ve had their fill of methane.
Lisa: " Since the 1960s methanotroph microbes have been used as a source of high density protein, so we can use the biomass as a protein for. Feed or fish feed or we can just return it back to soil similar to a bio fertilizer. If we wanna get a little more sophisticated. Methanotrophs have also been noted as creators of biodegradable plastic precursors. They can also make precursors to biofuels or cosmetics."
But there’s still plenty that research teams like hers are figuring out.
And there’s no clear proof of concept for how to do this at a big enough scale.
Lisa: " Some people have thought about constructing bioreactors, but of course that gets very expensive, very fast and we also don't know what the unintended consequences are of putting structures on a landscape like Northern permafrost. So I think that the best possibility is to create microbe embedded materials that could be freeze dried or pelleted. So it's a way to augment large scale ecosystems with methanotroph microbes, but without building anything."
Even if something like this proves to be possible given bacteria interact with other organisms and create byproducts, including other gases this kind of biological geoengineering approach would need significant testing, monitoring, and oversight.
Lisa: "We have to be mindful that if we are manipulating the carbon cycle, we need to ensure that we're not making a worse greenhouse gas problem."
So like Alex she says understanding these little bacteria and helping them survive and thrive naturally… in existing environments is likely a better first step.
So alongside working on early prototypes for these bioreactors with Lisa Alex’s lab is still focused on that task of understanding everything they can about these bacteria.
And using what they’ve learned they’ve also begun finding other species with this same unique ability.
After more than enough time at the cold windy dump he’s taking us to the Cells in the Cold Lab at the Arctic University of Norway to take a look at their rare, valuable and growing collection of methanotrophs that can live on air.
Alex: " Yeah, so this is this is where the magic happens. Hahah I Always wanted to say that."
To be fair… the views over the fjords are pretty magical.
We head over to one of the lab benches by the window.
Alex: " We have a few cultures out here. Yeah."
Inside carefully sealed dishes are filter membranes floating on a thin layer of water.
Little white circles of bacteria grow on the surface.
Alex: "So this is our main guy. The first that was isolated methylocapsa gorgona, MG08 is the strain name. So yeah, the 08 is for 2008 when it was isolated."
Since they were discovered, the lab’s been putting these little guys through their paces to learn all they can about them including...
Alex: " They don't need light to grow."
And…
Alex: "They just keep on living and staying active for like years. Put them on one of these filters, I think. The colonies we have here. Yeah, they are four years old."
And another useful trick for Arctic environments…
Alex: " It can grow down to around 10 degrees, perhaps a bit lower. But it stays active, very active at 10 degrees. It consumes methane.
But we have other strains that have a more sort of arctic profile where, where they would grow much faster at at 15 degrees. Also below 10 degrees."
These other newer strains each of which took weeks or months to successfully isolate are safely sealed away in a special room.
Alex: "So this is our, storage So here we have bunch of different strains. Unfortunately, you cannot see the cells. See, here's one of the close relatives of Methylocapsa gorgona.
So It was isolated, also by this research group. (it’s) From Finmark , in northern Norway. Originally also not thought to be able to grow on air, but we found out, that it's able to do the same things.
So far we have identified four species. So that's confirmed, but we are working on several others . So I think in here we probably have like 10-15. Different ones.
As far as I know, there are not many labs that have actually cultivated any of these strains."
As he seals away these valuable stocks he says they’ll be closely analysing these new carefully isolated strains to understand their limits and to see how they might be used as well.
Alex: " We are definitely interested in seeing how well we can make these bacteria grow, either by genetic engineering or by just learning how to optimize their conditions. I think this is, this is very exciting to, to just discover the potential of these bacteria. And also to understand how these bacterias can respond to the future climate. I think that's gonna be a big thing.
And we, we still have those weird cultures growing that we have still not, identified how do they live and what do they do. So yeah, we are, we are still going there."
And for Lisa Stein the stakes are high to understand these little critters as quickly as possible.
Lisa: " If we're going to leverage microorganisms, whether it's, mitigating climate change, creating new food sources, looking for new pharmaceuticals, (then) understanding them further gives us more strategies.
The climate's always changing. but microbes are dramatic drivers of that change . And. What our biomes look like. So it's to our detriment to not pay attention to how climate change is impacting microbial communities. By understanding them further, we can also create solutions to our own problems."
And for Alex he says the story of their fortunate discovery is one to pay attention to.
Not just because of how this strain from Tromso’s dump might be used, but also because it’s yet another example of how giving scientists time and space for these little moments to follow their curiosity or to talk with colleagues often leads to the biggest breakthroughs.
Alex: " Research programs are growing and they're getting more and more controlled and managed to solve. I think research, can also get too efficient and too constrained and too focused on solving problems. but the thing is like we are facing problems that we are not even sure how to phrase the right questions, or we haven't, maybe, haven't even identified the problems yet. And so we need knowledge, basic knowledge about a lot of things that might become useful in the future. And. And the only way to stumble across important insights about things you don't know anything about is to just try out a lot of things.
We have to allow for accidents to happen. We also need to allow for a little bit of, of luck. I think that's very important."