Alistair McCormick discusses his work at the frontline of algae and cyanobacteria research with the McCormick Lab.
We’re talking the day after the launch of the 6th IPCC Synthesis Report, where scientists are saying ‘it’s now or never to limit climate change’. Against this backdrop, what role does carbon dioxide removal play in tackling climate change?
It has to play a central role. The correlation between the increase in carbon dioxide and the accelerating impacts of climate change has been known for decades and well publicised since the early 2000s. I wish we had started listening to the warnings a little bit sooner, but on the other hand there’s a lot of really interesting technology under development that’s exploring new ways of carbon removal.
In my area, one really exciting development has been the growth of systems biology into synthetic biology, and now into engineering biology. This evolution has brought in more disciplines – as an engineering biologist I’m able to work with, for example, material scientists and physicists more easily, which means that what we work on together is that much more impactful.
Tell me about the McCormick Lab and some of the projects you’re working on. What are the areas of carbon sequestration you’re most interested in?
We work in two broad research areas: plants and microalgae. The first area focuses on engineering plants to grow better, to help improve resilience and strengthen food security. In this regard, we’re trying to engineer CO2 concentrating mechanisms, or CCMs, into plants. Some plants (e.g. maize and sorghum) have evolved their own CCMs for effective natural carbon sequestration processes, but most plants don’t do this. We’re trying to use the efficient carbon capture systems that have evolved in cyanobacteria and algae, then introduce them into crop plants to improve carbon sequestration and productivity. We think about it as a series of pumps and vacuums that help to draw CO2 into the cell, where it can be captured as sugars for growth.
We’re starting to get some exciting results in this area. One of the structures that you have with algae is called a pyrenoid, which is a fascinating liquid-like structure in the chloroplast where carbon capturing reactions occur. They do this through Rubisco, the main CO2 capturing enzyme used by photosynthetic organisms, which is aggregated together in the pyrenoid. We’re building pyrenoids into plants to try to further enrich their Rubisco with CO2, so that it can operate faster and convert carbon dioxide into sugars more efficiently. This is really exciting not only for discovery science, but hopefully for making a real impact on drawing down carbon as well.
The other area we work on is cyanobacteria. My interest in cyanobacteria started when I was working at Chris Howe’s lab in Cambridge on bio-photovoltaic devices (BPVs), which is basically making batteries out of photosynthetic microbes. When I was there we were able to use cyanobacteria to power a simple digital clock for a few hours, but now they can power small microprocessors for several months.
While cyanobacteria are generally a promising area for carbon sequestration, they generally grow much more slowly than bacteria, like E. coli. Yet in recent years we’ve seen the discovery of several cyanobacterial strains that we’d consider fast-growing – some that match the growth rate of yeast. One of these is called Synechococcus sp PCC 11901, which not only grows fast but can also achieve extremely high cell densities (high biomass), meaning that it shows great potential as a carbon sequestration chassis. We’ve been working with a company called CyanoCapture to understand how this species is able to reach such high densities – because if we can understand the genes and metabolic pathways involved, we could potentially improve it further or even put this into other species and engineer them to be more efficient.
Can you explain to me about the link between using biotech to scale carbon sequestration and making commercially viable products (i.e. chemicals)?
For the ‘green biotechnology’ sector, the commercial targets tend to consist of high-value products, and the yields of these products are closely linked to the biomass you can achieve – the more biomass the better. In the UK, we have several exciting biotechnology companies targeting different products, from so called third- and fourth-generation biofuels at Phycobloom, nutraceuticals at Algaecytes and Algenuity, and natural colourants like the blue pigment-protein phycocyanin at ScotBio nearby Glasgow, who we’ve worked with quite a bit.
We’re really interested in understanding the extent to which strains can be engineered to produce different targets, or whether it’s better to try to find ways to engineer strains that we know are already better at producing fatty acids or proteins, for example, but are less easy to genetically engineer. This question is something that precedes commercial viability, but it’s mainly being looked at by academics at the moment. One thing that is always useful is to connect companies with academics more, to facilitate a better understanding of the demand side of things and speed up adoption of these new technologies.
Something that sometimes comes up when you talk to people about scaling biotechnology for carbon removal is the potential risk to ecosystems, for example toxic algal blooms. How should we think about risk?
There are two main ways that you can grow algae and cyanobacteria: one is open raceway ponds; the other is closed photobioreactors where you have more controlled growth. In terms of the potential risk of genetic modifications escaping into the wild, most GM traits introduced into algae and cyanobacteria are unlikely to give them an evolutionary advantage over those in the wild, so they would not be able to compete in the natural world and thus would quickly die out. Also, several researchers have been working on ways to contain cultures, such as by developing inducible kill switches, where you can kill algae or cyanobacteria by exposing them to, or withholding, a particular chemical.
It’s also worth saying that public perceptions are shifting on this – think about genetically modified crops. While there’s a historical narrative that these crops are ecologically harmful, the truth is that lots of the time they’re the opposite as many require fewer fertilisers and insecticides than non edited crops. We’re seeing this now with new trial studies at Rothamsted on wheat that has been gene-edited to reduce the levels of acrylamide – a potential carcinogen that food processors are keen to control. The way it’s being covered by the media is totally different to how GM issues were covered 10 to 20 years ago. Not only are we seeing coverage across left and right leaning publications, but also high acceptance within younger generations that genetic engineering is increasingly necessary to tackle lots of our biggest issues. As recently as 2012, large groups of protesters were threatening to disrupt such field trails in the UK, so a lot seems to have changed!
What has been your experience on the funding side of things for your research?
The main funding body in the UK for the work that I do is UKRI and more specifically BBSRC. I’ve also had success working with the IBioIC, the Scottish Industrial Biotechnology Innovation Centre, who are fantastic in terms of bringing together industry and academics. For example, they offer proof of concept grants, which have been incredibly useful for kickstarting ours and other researchers’ translational ideas.
Alongside governmental institutions, we’ve been lucky to secure funding from foundations and we’re always looking for other sources of potential funding such as angel investors. The challenge is that research tends to need long term, dependable funding. The issue with government funding is that it often prioritises smaller pots of money to get the research off the ground, but we don’t really have the bridge to scale finance to allow researchers to explore work in more detail. That’s one of the reasons why CTRF is so interesting, as it can help bridge this gap.
Tell me about your role with CTRF. What are you most excited about?
One of the key roles of the Advisory Council is to shape the portfolio of what CTRF does, so I’m really looking forward to seeing what comes through from the first call for proposals. The Council will look at the proposals and decide which areas CTRF will focus on, then direct money to where it’s needed to achieve the most impact.
One of the reasons why I think this algae and cyanobacteria are so exciting is that if they’re successful, they can be scaled relatively quickly with the right photobioreactor design, unlike plants, which can take 10-20 years to reach commercial viability due to long breeding cycles. As the community is assembling all of these fantastic engineering tools, and we now have high-throughput experimental facilities – like the Edinburgh Genome Foundry and others around the UK – we have the ability to get things up and running and iterate quickly. This allows us to think bigger, get faster and find solutions more quickly. Overall, I’m optimistic that CTRF can play a really important role here.