Environmental & Life SciencesView profile
Here is our in depth chat with Dr Toby Parkes, CEO and Founder of Rhizocore Technologies, as part of ‘Product | People | Potential’. Rhizocore Technologies are producing mycorrhizal fungi products to enhance tree planting success. By working with native fungi, the Rhizocore team are able to accelerate woodland regeneration in a sustainable and symbiotic manner. Following the completion of Toby’s PhD and work with Deep Science Ventures, Rhizocore were founded in 2021 and are now a team of 7.
The purpose of article series ‘Product | People | Potential’ is to feature and showcase the very best UK start-ups with grand potential, truly inspiring businesses that are shaking up their sector. We capture and share the stories behind the name. We collate authentic peer to peer real talk, while celebrating the growth and success thus far and gather a glimpse of what’s ahead.
Toby: Hi, I’m Toby and I am the CEO of Rhizocore. I am a plant scientist by training, and I have spent the best part of my academic career trying to understand how plants communicate with other organisms that they encounter within their environment. This ranges from fungi to microbes and anything else they come across. My PhD is in plant pathology, and I have also done some genetic engineering work to really kind of try to understand how the plant immune system works and evolved. Prior to my PhD, I was a researcher at the Royal Botanic Gardens at Kew where I worked on the Millennium Seed Bank Project. I was researching plant germination biology and the early stages of plant life so a lot of tissue culture work, and a lot of low temperature storage cryo-preservation. I worked with everything from orchids through to palms when I was at Kew and that is where I first ran into mycorrhizal world as Orchids are completely obligate on mycorrhizal fungi (they cannot survive without them). This was my entry into the mycorrhizal space.
Rhizocore was built to solve a distinct problem that we have with tree planting, given that the world is starting to plant more trees. The places we typically plant trees are areas that have not had trees for a very long time. This is problematic for a bunch of symbiotic organisms that are fairly critical for supporting forest woodland ecosystem establishment and health. This is what we call the ectomycorrhizal group of fungi. This group of fungi are very specifically adapted to associate with trees and they do not survive if there are no trees. This means that when you are planting new trees in areas that haven’t had trees for a long period of time these supporting networks of fungi don’t exist, which means you have much higher mortality rate of trees. Some of our customers lost 80% of the trees in the first 3 years post-planting and you have reduced growth rate of trees. Because of this, you are massively limiting the potential for new woodlands to grow as well as they could and you are also limiting the amount of carbon sequestration that goes on when planting woodlands. The fungi are pretty critical in terms of converting carbon compounds in tree biomass into long lasting compounds that sit within the soil carbon pool. Without established networks of mycorrhizal fungi you don’t get that transition of carbon into the soil carbon pool. So, not only do we need that, but they also work on what we call forest and woodland health. When we have well-established networks of mycorrhizal fungi, this allows trees to shuttle nutrients and water between different trees within the woodland and connect up. You may have heard the phrase ‘wood wife web’ but it’s pretty important for things like drought. So, when you have well-connected woodlands and you’ve got different areas on site which you might have some trees that are over in a wetter site, they’re able to shuttle water across to different trees. This means that you have got woodlands with much greater tolerance to drought conditions. If you’ve got good microbial networks, which occur in a place you would typically think is wet, like Scotland where we predominantly work at the moment, then a mild drought can be quite problematic. Mild droughts used to be a once in a 30-year event but with the trees that we plant now and over the next 30 to 40 years (average tree lifespan in a commercial forestry) then those drought events will go from once every 30 years to once every 3 years! This shows it is kind of critical that when we think about trees and forestry, that we think about protecting for the next 30 to 40 years ahead as a minimum.
Toby: It is a very complex picture. So, the first thing to say is that the ectomycorrhizal group of fungi are the ones that predominantly associate with trees. However, it’s more complicated than that as some trees associate with another group of mycorrhizal fungi that we call the arbuscular mycorrhizal fungi. These are the typical fungi that you see in agricultural settings or horticulture. If you go to a garden centre and buy something like ‘rootgrow’, this is arbuscular mycorrhizal fungi. Arbuscular species typically associate with herbaceous plants and grasses. However, some tree species which you associate more with grassland ecosystems and hedgerow trees have arbuscular fungi too. Hawthorns are a good example of this as they only associate with arbuscular mycorrhizal fungi. Some tree species have very specific associations with certain groups of fungi; for example, Scots Pine tends to associate with a particular genus known as the Suillus group, some of which don’t associate with any other species. You also get other ectomycorrhizal fungi that are more generalists. For example, the deceivers, such as the purple Amethyst deceiver, and associate with everything from Oak to Beech. You’ll also find them associated with pine and spruce trees, so the assemblages of mycorrhizal fungi communities are very different depending on the host species present. It is also dependent on soil conditions, as mycorrhizal fungi can be very picky about things like pH, phosphorous, and nitrogen conditions in soil. The fungi that exist is very dependent on hosts and soil conditions and also the stage the forest is in. In the same way that you have plants and forests in a succession process, you have pioneer species of fungi that make way for late-stage species, you have the same thing with ectomycorrhizal group of fungi. For example, Amethyst deceivers are a pioneer species. You will find them associating with young trees and they are able to survive off of small saplings, whereas some other species, like Ceps and porcinis, only occur when trees are 20-30 years old and are called late-stage mycorrhizal species. They only occur on older trees as they have a much higher carbon demand on the tree, so a smaller tree with a smaller amount of leaves won’t have enough carbon sustenance to support late-stage mycorrhizal fungi. Theres a huge amount of turnover going on here. There are studies that have shown that one mature tree in a mature woodland can have over 30 different species of microbes or fungi on its’ root system.
Toby: Yes, of course. It started when I was working with Deep Science Ventures, which is a venture builder studio. I basically worked there to build concept companies under a broad remit of acceleration of plant growth. We looked at building companies in everything from controlled environments through to symbiotic organisms. We looked at cell culture stuff to see whether you could do materials design with bioreactors. At Deep Science Ventures, we eventually lined up 10 to 15 concept stage companies after around the 6 to 8 months and then said okay, which of these companies has the biggest upside for people and the planet; Rhizocore came out on top.
Rhizo, the concept behind Rhizocore, initially came from a conversation I had with forestry customers. I started asking them where they were using symbiotic organisms, particularly the ectomycorrhizal fungal group, thinking that we would be looking at how to improve the fungi already used in the systems. I was pretty gobsmacked when they basically said we don’t use them, and half the time they said what are they? It is something I kind of took for granted as a researcher in the field, as we have 50 years plus of sound scientific literature on how important these organisms are for trees. Rhizocore was built to answer the question of why we are not using this scientific knowledge to help the Earth. We realised a lot of things that had historically been tried in nurseries that hadn’t gone well, were due to nurseries not being a good place to try and apply mycorrhizal fungi for a whole plethora of reasons. I started to design a product that can fit into tree planting systems when the tree is planted. This is not particularly easy and a lot of people, particularly researchers, in the past have tried from a very research-oriented viewpoint of making a liquid inoculant that is injected into the ground. This doesn’t work, and neither does dunking the root system into the inoculant. Giving a product like this to foresters, you have to understand that most trees are still planted by hand. You basically have a contractor in the field that’s got a tree and asking them to dump the root system for every tree in a tank before planting won’t happen as most contractors are paid by how many trees they plant an hour. If you increase the time it takes to plant a tree, you’re going to get no uptake of your product within the market. The products either didn’t work, or were not usable in the context of tree planting. We came up with a pellet-based system, which we still use at the moment, so that we can deliver mycorrhizal fungi (multiple species and strains) into new planting situations with an easy to apply product that can be used by contractors.
Toby: We have not faced many issues at this point in terms of recruitment, but we have mainly been hiring junior talent which is easier to come by. One thing that I would warn is don’t get fixated on PhD level students. PhD’s have their place and it is a training ground for certain skillsets in terms of the innovation space, but on the most part, PhD’s are bad at training personal skills, managerial skills, things like that which are actually quite important. I think that sometimes people can look at a CV and have a tick box and think you need a PhD to do something whereas actually there’s a lot of better talent that doesn’t have a PhD but do have more personal skills that are useful. Don’t get blindsided by having a PhD as a must.
The other thing that we do that is slightly different but is becoming more common, is having all staff on a 4 day week. We have found this to be incredibly useful for attracting talent and the productivity that we get out of them is beyond what you would normally expect. The academic literature supports 4-day working weeks. I would strongly recommend suggesting contracts that way because A, you’ll attract better people and B, those people will work much better for you for it. You’ll build a good culture. I am anticipating that we will hit problems in terms of recruitment as we will be looking for quite specialist skill sets with mycologists. The issue with this is that it is not a discipline that is trained for anymore; most biology degrees do not incorporate much plant science, let alone fungi! We are having to hire people that are hobbyist mycologists. Many are essentially self-taught and it remains a hugely unexplored area of science. We have been able to find a relatively good amount of junior people at a good level but hiring senior people that have got some understanding of the mycorrhizal world is tricky.
Toby: Globally, fungi as a kingdom are pretty ignored in terms of schooling. There are some areas of the world that have cultures that are more knowledgeable of the fungal kingdom. For example, Eastern Europe and Scandinavia have a big foraging culture. It is funny as when we go out to site on large estates sometimes there will be people working and if theyre from Eastern Europe they often have a phenomenal knowledge about where the fungi grow in the forest.
We are basically collecting strains to propagate and supply these strains back to the estates, so we ask if the staff have seen any specific species on-site and they can often point to the tree host species the fungi are found on. People from different cultures have knowledge but aren’t trained through a schooling system, it is knowledge passed down through generations.
Toby: Yes, there is a big hole in university training. I was lucky at Bath (University) as during the 1st year of the Biology degree there was a whole module running through every single kingdom. The lab sessions went through the diversity of life on Earth, and we ran fungal practical’s to teach people. This was the first time many people had ever come into contract with the fungal world. It is bizarre as they ran a module on plant pathology, but you need to know fungal pathology if you want to do anything in plant pathology as most pathogens are fungi. I got lucky in the university that I was at as you would expect any biology degree to reach you about the whole biological kingdom, not just the mammal side of it. There is a lack of understanding and I think the organisms like plants that cannot move out of the way and so have to adapt are the most fascinating. We are not complex organisms at all.
Toby: We deal with both plantations and conservation planters. At the moment, our largest customer base is natural regeneration focused, and the reason behind this is that our products are the moment are very expensive within the market and trees used in natural regeneration are more expensive than commercial trees. Having said that, I’d say commercial forestry is more hesitant to move to a new technology until it’s got a reasonable amount of data behind it, which for trees takes a long time. We’re probably a 70:30 split on conservation: forestry. We are getting quite a lot more interest from the commercial forestry sector; we basically say as long as your trees are ectomycorrhizal trees, we’re pretty agnostic between who we work with because we can improve the biodiversity and carbon sequestration. There is the potential for any woodlands that are using actor-associating trees and so even in a spruce plantation we can improve the soil diversity that occurs there. We would rather that they were planting a mix of trees that are more useful to the world and biodiversity that we have in our systems. However, you have to recognise that were still going to be needing to produce pulp and paper and so we want to work at that level as well.
With market fit, we’re lucky with mycorrhizal fungi having so many different value propositions in terms of growth rate, mortality, droughts, disease resistance, and carbon sequestration, and different people are interested in different things. Woodland natural regeneration planting organisations are typically most interested in mortality rates because they are losing trees. It is really common to see a 40-50% mortality rate, and not unheard of to see 80-100% mortality! Commercial forestry is more interested in the growth rate of trees. There is also the new customer block for carbon insetting companies, which are large corporates that are basically wanting to generate carbon credits internally themselves. In addition, new biodiversity markets are emerging where A biodiversity credit is expected to trade for around £20,000 a unit, and you can probably get 4 to 5 units per Ha of pastureland that’s being converted from pasture to woodland, so that’s going to be a pretty big game changer in terms of the financial flows.
Toby: Yes; ectomycorrhizal fungi can be a pain to work with! Not only do you have very specific in terms of species and strains you pick, but also isolating those to get pure cultures is really difficult and the attrition rate is high, particularly with any hydrophilic caps.
We typically find mushrooms that are the species we are after, and then isolate the tissue from those and put this in a petri dish. We then propagate through the fermentation that we use to scale-up. Some species, when they are hydrophilic, all water washes into the cap and washes bacterial contaminants, such as mould spores, from the outside of the mushroom to the inside. When we try and isolate, you get a ridiculous amount of contamination. This has been frustrating with two species groups; the deceivers and the poison pies. We would like to do a lot more work with these species groups, but it is really difficult to isolate in the culture so they’ve become frustrating to work with.
The other thing is that we work on a very different business model to what you typically see out there. I would expect more companies to go towards this in the future, but it is more complex in that the biological organisms that we supply are sourced at regional level. We have to build a complete strain library and that’s overlaid over the kind of biogeography and some geological kind of maps of the UK. We use an existing model that’s in forestry called the forestry provenance or seed zone model. The UK is split into 24 different geographic regions, and we are building a library of each one. This is quite challenging in terms of getting all of the strains as there, fungi experience different soil conditions and are adapted to these sites. Operationally, it is quite complex for us as we are building a huge biological resource that we are marching to sites to get the best performance.
Toby: There are two different routes here. It depends whether we’re working in a new zone or not. Once we have got the material, it’s not too difficult for us to spin it up and it takes us about 3 months from order through to product. If we don’t have the material, we partner up with organisations that are in the zone and we collect in the autumn. It depends on how far away we are from the autumn season. It takes us between 2-4 weeks to isolate the fungi and produce pure cultures and then we produce a product over the next 3 months or so. Once we have built a library of one zone, we don’t need to go back to it, as we can just return to the strains we have in the freezer and re-animate them. We have strains across the UK and are building our library for Ireland, so we are expanding our geographical remit. We will be looking to get at least two new European countries. We want to be operating in almost every geography in the next 5-10 years.
Toby: Temperate zones typically have similar assemblages of species and mixes so you will find some species that we work with in Northern Europe also in North America. Across temperate zones you’re typically seeing the same type of species mainly because the types of trees planted are pretty similar. Even if you are in the States and planting pines, they are not that dissimilar to a British pine species.
Tropical trees are quite different, as are rainforest tree species. The rainforest species are more associated with the arbuscular mycorrhizal fungi group, so what we do is less important in rainforest areas. However, there are huge areas of temperate forest woodland on the East Coast of Brazil or in areas such as , Australia.
Toby: This is a tricky one. I would say with investment, it takes longer than you initially anticipate, so give yourself enough time and prep enough materials. Try and identify a good candidate list of investment groups that can get intros from your network too. I have never had to do a cold approach to a VC that I am interested in, I’m always getting an intro from one of our existing investors or other companies around us.
The other thing I would say is that pitching is not typically what you would think. I don’t know whether this is the sector that we’re in or whether things are generally changing, but it is very rare that we live pitch, even on a video call. This is kind of a red flag to me that the investor group is not particularly good. Typically we have found with the best investors is that you’ll send over materials to them prior to the intro calls, or you’ll have an initial intro call and then send materials to them. They will review these materials and then spend an hour plus with you, diving into what they care about and there’s much more dialogue around specific questions. It is more about explaining what you are doing and far more comfortable an experience. You need to know your material inside out and back to front because you will be explaining without any material in front of you.
I also think within the climate impact biodiversity sector that there is a lot of powder to burn, which is unusual in the global economic state we are in. We have just closed our seed round and we are lucky in that we were hugely oversubscribed on that so we were able to be picky with which investors to go with. You need to know the type of investor you are looking for, the skills you want them to bring, and how they can add to your company because they’re going to sit on your board. You need to know how you interact and deal with investors so pre-decide the key things that you’re looking for in an investor.
You also need to do investor due diligence. Many people think the best way to do this is through other companies that they work with but I tend to find the best way to do it is through other investors and VC’s who sit on boards and have worked with these new investors before. They will be more honest with you on how good the investors are.
Thank you for your time, Toby!