Scottish innovation takes root in fight against potato disease
Scottish researchers have developed a promising new approach to protecting seed potato crops from one of the sector's most damaging diseases by harnessing bacteria's own natural defence systems.
The technology, supported in its early stages by the Industrial Biotechnology Innovation Centre (IBioIC), is now heading towards commercialisation through a new spin-out company, Casdu Crop Solutions.
Blackleg and soft rot, caused mainly by the bacterium Pectobacterium atrosepticum, costs the UK potato industry an estimated £50 million a year, with global losses potentially running into the billions.[1] Infections in field crops typically result from bacteria introduced through infected seed tubers. Scotland is one of Europe's leading producers of seed potatoes, and growers operate under strict certification rules to eliminate infected tubers and prevent disease spreading through the supply chain. Even infection levels above 0.1% can see a crop downgraded, costing growers as much as £100,000 per incident. [2]
The new treatment uses bacteriocins - naturally occurring protein antibiotics that bacteria produce to kill competing strains. Scientists believe they can harness these as a treatment, offering growers an environmentally friendly alternative to copper-based treatments and antibiotics.
The research group, led by Dr Joel Milner from the University of Glasgow, has spent more than 15 years searching for and studying bacteriocins. Unlike conventional antibiotics, bacteriocins naturally target only specific harmful strains while leaving beneficial bacteria largely unaffected.
Using advanced genome-mining techniques, the team identified around 50 potential bacteriocins and found seven with promising disease-fighting properties. Further testing showed that four were effective against UK strains of blackleg, while others demonstrated activity against related strains of bacteria that cause the same disease around the world.
The team also found that combining different types of bacteriocins can further improve effectiveness. Because each type targets harmful bacteria in a different way, this could also help reduce the risk of resistance developing.
Early glasshouse trials showed the new treatment can suppress infection in seed tubers, and field and storage trials are now under way with the James Hutton Institute. The team estimates the treatment could be produced at low cost and deployed at scale, offering a potentially practical and sustainable solution for growers while representing a significant scientific breakthrough. Support from IBioIC allowed the team to generate the data needed to advance the technology towards commercialisation.
The need for a solution to tackle blackleg and soft rot is becoming increasingly urgent. Wetter summers linked to climate change are expected to create conditions where infection spreads more easily, whilst growers in drier parts of the UK face a difficult balancing act: applying enough irrigation to prevent scab, a common soil-borne disease which causes rough scabby patches, without the risk of encouraging blackleg.
This makes the environmental case significant too. A successful treatment could reduce reliance on copper and antibiotic-based treatments, cut crop losses and waste, and potentially ease the strict low-temperature storage requirements currently used to slow bacterial growth in stored potatoes – reducing both energy use and cost for growers.
Along with the support from IBioIC and the University of Glasgow's Impact Accelerator Fund, the team has secured further backing from the Biotechnology and Biological Sciences Research Council (BBSRC). The researchers are now preparing to launch Casdu, which will take the technology towards commercial deployment.
Dr Joel Milner, one of the founders of Casdu Crop Solutions, said: “What we’re working on is a novel antimicrobial solution to one of the most devastating diseases affecting potatoes. It’s likely to be affordable, easy to apply, and environmentally friendly. This isn’t about a silver-bullet cure. It’s about delivering a genuine improvement in the sustainability of an industry that matters hugely to Scotland, the wider UK, and indeed all countries where potatoes are grown.”
Dr Liz Fletcher, director of impact and deputy chief executive at IBioIC, said: "Blackleg and soft rot cost growers dearly every year, so backing Joel's early work was an easy decision. What's exciting here isn't just the science, it's that the team has a genuine route to market, with a treatment that could meaningfully cut reliance on the environmentally damaging methods growers have had to rely on until now. We're looking forward to supporting them as they move towards a spin-out and closer to getting this into growers' hands."
[1] The James Hutton Institute
For more information, read our case study: Saving potatoes from bacterial disease