September 10, 2021

Seaweed, Agar and Algae

By Conor McKechnie and Dodi Axelson

Seaweed, Agar and Algae

Conor brings us into the world of slime: seaweed, agar, and algae. Algae gave us the atmosphere that we have today and is still coming to our aid against climate change. Photobiologist Peter Ralph, who once called himself Dr. Death, explains how algae has provided him with newfound hope for the future to solve climate change


CONOR: So, Dodi you know how I revel in the incredible unlikeliness of being, and the fact that we exist at all, let alone at the same time in history and that we even know each other and work together, and do a fun podcast and all that. And that if one tiny thing was different, like none of this, this veritable amazing thing of life on Earth just wouldn't be.

DODI: Just one small slip.

CONOR: That's exactly right. And every now and then I get on a thing about something really small having a huge amount to do with all of life being possible.

DODI: What do you mean every now and then? Okay, so last year, you were pretty excited about mushrooms, fungi, the microbiome...

CONOR: Exactly. I'm still flying the fungi flag, that's for sure. But now there's more. So, what do you think connects all of these things? Seaside vacations, sushi, cosmetics, biofuels, meat alternatives, intergenerational space travel, biological medicines?

DODI: Are we going to talk about millennials today?

CONOR: No, we're not. So, the answer is seaweed, or rather algae and then seaweed, because they are the special ingredients of biotech, that we're talking about in today's episode of Discovery Matters.

PETER RALPH: So, I've been working in climate research for 30 years now. I started out my career, looking at coral bleaching, polar sea ice, loss of algae in those systems, but essentially, I'm a photobiologist. That means I work with understanding how photosynthesis works in plants, whether they're tiny singular cell plants or higher plants, it doesn't matter. And I got to a point where all I was doing was researching the death of ecosystems. And as a public speaker, I became Dr. Death. All I could tell the public was what was wrong with, or how, climate change was destroying vulnerable and really critical ecosystems. About eight years ago, a new dean showed up at my university and said, 'Oh, what do you think about biofuels?' And I said, 'I think it's a crock, we're never going to be able to make it', and he said, 'You're exactly the person that should be trying to fix it, because you know what's wrong with it!' I sat back and thought, 'Wow, he's absolutely right'.

DODI: Hold up. Who is this Dr. Death?

PETER RALPH: I'm Peter Ralph. I'm the Executive Director of Climate Change Cluster at the University of Technology in Sydney.

CONOR: Peter is a photobiologist. He specializes in the interaction between light and living organisms, and he does a lot of work with algae.

DODI: Okay. So, he sees algae and seaweed as possible answers to helping fight climate change.

CONOR: Exactly, and it's beyond cool how widespread the applications that he and his colleagues are working on actually are.

PETER RALPH: So, our work in our institute covers, plastic production covers, pigments for food, protein for human consumption, CO2 capture from different types of industries, bioremediation, you name it, we can address a massive diversity of problems, because we're working with these very simple cells. These cells, these 300 000 species of them 300 000 different genomes of different genetic architecture, that we can either select or manipulate to solve a problem. So, I'm very, very excited about the research opportunities, and how we can change things because of the flexibility of the organisms we're working with, and the absolute need for these solutions now.

CONOR: And now to make it even cooler. The basics of growing algae are pretty simple, kind of all you need is to, like, not look after your swimming pool.

PETER RALPH: So, to culture and keep algae alive, you need basically salts, nutrients, and light. The salts in the nutrients, nitrogen, phosphorus, carbon, CO2, and a bit of light, and that's it. So, they're extremely easy. You don't need growth factors. You don't need fetal bovine serum, you don't need all of these extra growth factors. So dead easy to grow.

DODI: Oh, interesting because serum from cattle is a vital ingredient growing mammalian cells in biomedical applications.

CONOR: Exactly. So, there's a possible route to reducing biomedicine's reliance on animals by growing protein in algae. Back to Peter...

PETER RALPH: One of the challenges for your audience to recognize is I did say one of the criteria is light. So, a lot of the industrial-scale bioreactors, for fermentation, don't have light. So, we've got to get light into the reactors. But light is not a deal breaker really, when you consider you're going down to cents for your costs of media, as opposed to tens of dollars per litres, so they're very, very cheap. Transformability. They're as easy as CHO cells. The problem with the industry is our lab, and a number of labs around the world, have been finding transformation capacity in new strains. Chlorella and Chlamydomonas are a few lab rats that are easily transferable, and all of their genetic structures are known, the safe harbors, everything's been worked out. But for a new exciting alga that's got an exciting job genetic structure there is a little bit of work to do in getting its genome sorted out, worked out how to do the transformation, but all of the techniques are basically worked out. So, it's a couple of years to get a new species up and running. But if you want to put a transformation into an existing lab rat, microalgae, it's doable.

CONOR: As you can see, despite a few barriers, it definitely has scalability.

DODI: That sounds awesome. So, you grow massive amounts of algae in vats, and they express protein, and then what?

CONOR: Well, you know, then you need to purify those proteins. And you do that with...?

DODI: Resins! Like protein A, we've talked about that.

CONOR: Exactly. Remember that first ever episode of the Discovery Matters podcast. So, resins like protein A are based on...?

DODI: Agarose.

CONOR: Which is made from...?

DODI: Agar.

CONOR: Which is made from...?

DODI: Seaweed!

CONOR: Boom! Seaweed, that could be replaced by algae or microalgae to reduce the need for large monoculture seaweed plantations that may not be that great for biodiversity.

PETER RALPH: So, what we've got to do is we've got to look for its chemistry, basically. We're going to be doing a lot of screening, because as I said, microalgae make a lot of sugars. They make a lot of sugars, and sometimes they're photosynthesis, they're capturing light, capturing CO2, and they just put out these sugars. They're called EPS, so extra polymeric substances. If those, almost waste products of photosynthesis, can be used and they have properties that are similar to agar, then we've got a new source of it. And that's an alga that's just driving its photosystems, capturing light, and making a waste product, and it does have sugars in it, it just depends on whether or not we can tweak it to be agar based. And that just comes down to the chemistry. So, there's a range of chemistry that we have to look at. We look at a thing called rheology. And that's the gelling property of the agar, how it has physical tensile strength, we have to look at temperatures that it's solid at. And then we look at its chemical structure. So, this huge diversity of needs for agar and its ability to have stabilizing response to chemical reactions. So, yes, not all agars are created equally. And the diversity of agars means that some of these products could go to different industries.

DODI: So, seaweed makes agar or as you say...?

CONOR: Agar.

DODI: Makes agarose, makes resins used in purifying medicines.

CONOR: Exactly. And here's Jonas Gustafsson, one of our principal scientists, to tell us how that works.

JONAS GUSTAFSSON: In a very simplified picture, it's essentially a two-step extraction procedure. What we do from seaweed to agar is extracting the agarose polymers in a slightly unrefined format, ending up with the intermediate product of agar. Then as we go from agar to agarose, we do a similar extraction procedure, this time a bit more refined, ending up with agarose polymer in a more purified format than what we had in the agar, and slightly chemically modified. Some sugar components are converted. In general, you could produce chromatography resin from a wide range of seaweeds.

DODI: So, it is possible in the future that we might grow biopharmaceuticals in algae, and then use algae derived resins to purify them, all of which is reducing the environmental impact of the industry, and coming back to what we talked about on an earlier episode with those 5Rs.

CONOR: Exactly! Cool, right? And wait, there's a whole other level of cool to come because not only could algae help us clean up this mess that we've made of our atmosphere, algae actually created the atmosphere in the first place.

DODI: And now my mind is blown.

PETER RALPH: The atmosphere, the oxygen that we breathe, was created by cyanobacteria, billions of years ago. So, these very, very fundamental cells, which are close to a bacteria, but they've got photosynthesis in them, they are the ones that basically transformed the planet. We still use those. Cyanobacteria are extremely useful in industrial biotech. But then there's the newer microalgae, the younger ones, that have got a whole new set of cellular form, cellular, and genetic capacity. Then from the microalgae, you move into the seaweeds, which are a whole bunch of different cells running different tissues within the plant, then you go to higher plants. So, they're all a continuum. And they all have common ancestries and common genetic structures. But as they branch into different directions, they have new and novel capacities.

DODI: So, Peter sees uses for this entire spectrum, from cyanobacteria to microalgae, to algae to seaweed to help us heal the ecosystem.

CONOR: I know, it's crazy, isn't it? It's like going back a billion years and saying, 'Algae, you know, that atmosphere that you really kindly made for us, we kind of screwed it up...'

DODI: Yeh, 'do you still have the recipe to fix it?'

CONOR: 'Could you just fix it for us, please?'

DODI: And then how much algae are we actually going to need to fix the mistakes that we have made as humanity?

CONOR: Yes. So, look, the potential is far reaching, and the demand could be huge.

PETER RALPH: The scale is immense. Let me break it into three different types. So basically, a microalgal cell has got sugars, it's got protein, it's got oil. So, if you use the oils, then you're going to be making petroleum. So, you're going to be making fuels, or cosmetics. If you're going to be using the protein, then you are going to be making foods. So human foods, animal feeds, whole range of products there. The sugars are the really exciting thing, because that's where you go into your plastics, you can go into your agars, you can go into a whole range of different compounds that are sugar derived. So, because you've got such a diverse range of building blocks, the industries that you can approach are immense. Our labs have done a huge amount of work with plastics, both from seaweeds and from microalgae. We're working closely in human food production, we're working in pigment production, we're working in animal feeds, replacing omegas, omega threes. So, they are one of the easiest things because algae naturally make omega threes. We get the omegas from fish, but where do fish get it in the first place? They get it from the microalgae. So instead of having to culture up large amounts of oily fish to get the omegas you go straight to the algae. The breadth of industries is immense.

DODI: So, if these seaweeds, kelps, things like that can help heal the ecosystem, what does our future look like?

CONOR: Well, here's Peter again.

PETER RALPH: 50 years into the future, the biggest thing for facing climate change, where the bioeconomy is going to come in, is going to be capturing all the carbon. So, we're going to be having systems whereby we will still have some gas fired power plants in 50 years’ time. Hopefully we won't have any coal fired power plants. We will have a thing called Jenbacher™, Jenbacher™ are a type of engine that works off methane production. All of these systems of power generation are still going to have a little bit of CO22. We're going to have CO2 capture on those, and we're going to have a confluence of waste streams from sewage, and captured carbon being brought together, we're going to be making plastics, we're going to be making carbon sequestration products that are going to go into buildings, that are going to go into a whole range of our lifestyles. So, we're going to be rapidly drawing down our CO2, cleaning up the planet, and making stuff for society that is needed. And we're gonna reduce the temperature of the planet.

CONOR: It seems that multiple industries are now realizing the importance of algae, and microalgae, and seaweed, and kelp, and so on. And some industry partners have approached Peter for help. Even if it's not immediately viable or cost effective, attitudes are really clearly changing.

DODI: I love that curiosity is going to bring us forward.

CONOR: Yeah, exactly.

DODI: But what about when it all goes wrong? So, we do occasionally like to dip into the dystopia. If we genetically engineer microalgae, how do we prevent it from becoming a rampaging gloop that takes over the world?

CONOR: Of course, I mean, it's a question we ask ourselves every day. You know me, we talk sci-fi, me and Peter, and Peter is mindful of that worry.

PETER RALPH: I think the time is going to come where society does need some very, very serious engineered tough strains to do some very, very heavy lifting. I think there's enough thought that's going into that, our labs have been doing it for five years and there's labs around the world that are preparing it, I think when society needs those strongly engineered strains we will have enough protection, that we don't have green glue taking over the world. And we can protect the planet from these engineered strains. But there's so much that we can do with just straight wild types. And we've got to remember, a wild type is already the Rambo. It's the one that can survive in the harshest environments out there. Anything that we do to any of our engineered strains, they just generally going to be much weaker, and they're going to be industrially. We're going to have to nurture them in industrial situations, so the chance of them escaping and causing chaos, I think is moderately low.

CONOR: So sci-fi obsession number one sorted. Little chance of armageddon by engineered microalgae because evolution's own algae are just extraordinary already.

DODI: Huge relief!

CONOR: Sci-fi obsession number two, space travel, you ready?

DODI: Oh, am I? Okay, I guess I have to be. Hit me!

PETER RALPH: The opportunities for space exploration, whether it's Mars or another planet, we need systems on the spacecraft for removing the CO2, we need regeneration of oxygen. That's something that they currently are already tinkering with. One of the other exciting things is when you get to Mars, what are you going to build all your stuff with? You are going to need 3D printers, you are going to need to have polymers that you can actually make stuff with. The best way to get that is using microalgae. So, we can have microalgal strains that can generate the plastics that can be used for 3D printing. You can grow your protein. So, on the movie Martian, he used his waste to grow potatoes. I'd be using my waste to grow algae to have protein, I'm going to have a lot more protein. And we can find algal trains that are going to work with the wavelengths of light that are going to be on other planets. So, I think yes, algae are absolutely going to be a key part to space travel, and space colonization. Another movie to reflect on. Did you see Blade Runner 2049?

DODI: Conor, you've seen Blade Runner?

CONOR: Yeah. What a crazy question, right? You know how I love that film and its subsequent film. I love sci-fi rooted inside fact.

PETER RALPH: So, there is these two references to algae in the dystopian 2049. So, there's algae soup in one of the kitchens. So, they're actually selling algae soup. But then the guys growing his witchetty grubs in an algae bath. Now, the protein was coming from the witchetty grubs, but equally that algae could have been dried down to a powder. He could have been making pasta, he could have been making any number of food substrates that are much more appealing than witchetty grubs. The technology they used there were the bioreactors, and the swimming pool is exactly what we use. So, there wasn't a huge amount of science fiction in that movie.

DODI: So, microalgae are the future and if Peter Ralph, who called himself Dr. Death but really seems to be Dr not-death, if he can feel positive about the future, I guess we all can.

CONOR: Like I said at the top it's the future and it's the past. It's one of the very reasons we're here today having this conversation, it's the only reason we have the oxygen in the atmosphere that we have. It all started with microalgae.

DODI: Not that you're going to dwell on that at all Conor?

CONOR: Not at all and you know a future episode, having done fungus and now having done slime and the microbiome, we've done all the three key ingredients in any five-year-old boys like happy place, guess what's coming back?

DODI: Oh, it could only be things with many many legs.

CONOR: Yes, it's bugs. Bugs are next.

DODI: Thank you for listening to our episode about slime. Stay tuned for bugs.

CONOR: Discovery Matters' executive producer is Andrea Kilin and was produced with the help of Bethany Grace Armitt-Brewster. Music by Thomas Henley. Additional music is from Epidemic Sound. My name is Conor McKechnie.

DODI: And my name is Dodi Axelson. Make sure to give us a rating on the platform you use to listen to this podcast. Thank you so much for listening.

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