A role for soil in food safety for crops

© iStock/ahavelaar

The Microbiology Society is undertaking a project entitled A Sustainable Future as part of our 75th Anniversary, which aims to highlight the Sustainable Development Goals (SDGs) to our members and empower them to use their research to evidence and impact the goals. Earlier this year, we put a call out to our members to submit case studies in the following three areas: antimicrobial resistance, soil health and the circular economy.

This case study is written by Professor Nicola Holden, a member of the Microbiology Society based in the Rural Land Use Department at Scotland’s Rural College (SRUC), Aberdeen, UK on behalf of an European Union Cooperation in Science and Technology (COST) Action, HuPlantControl. The (COST) Action’s aim is to build networks of expertise across EU member states to address strategically relevant and contemporary questions. The below case study focuses on Soil Health; maintaining the health of our soils has gained increasing prominence in recent years. Soils are essential for the global food system and regulate water, carbon and nitrogen cycles but are put under pressure from population growth and climate change.

What are the challenges/needs that this research/initiative addresses?

Our COST Action addresses the issue of contamination of fresh produce by human pathogens. This is a serious problem in horticultural production, with a large proportion of foodborne illness now arising from contaminated produce instead of meat & dairy products. Contaminants can occur from a variety of sources, including endemic soil or plant inhabitants, while others can persist in soil and on plants but are ultimately derived from animal reservoirs. Our project has focused attention on bacteria and fungi that cause human disease, because these groups show traits of true biological kingdom-crossers. Edible plants can also transmit pathogenic virus and protists although they require humans/animals for proliferation.

This issue is embedded in soil health, since we have to consider the holobiont system of the crop plant, which is ultimately dependent on the soil microbiome. Environmental and agronomic influences have profound impacts on the soil microbiome, which in turn impacts on pathogenic microbes within the system.

What findings and solutions were provided by this research/initiative?

The project has built a pan-European network of excellence with a focus on the impact of plant microbiomes on human health. Importantly, we have had excellent support from industry and regulatory authorities, achieving the overall aim of ensuring relevant work, with the applicable outcomes. We have done so with working groups examining different aspects of the topic (ecology; taxonomy; virulence; risk management) that feed into a fifth group dedicated to knowledge exchange. It has resulted in tangible outcomes aimed at primary producers, those associated with the food industry and public health agencies. The activities range from targeted exchange visits to build research capability, training school, workshops with primary producers, scientific conferences and stakeholder meetings.

How can this research/initiative support the transition to a more sustainable future?

Agriculture is undergoing monumental changes from a number of diverse drivers, which can work in complementarity, or in opposition. Whether its changes in farming practices, climatic conditions or technological innovation, they all affect the soil microbiome to varying extents, which from our perspective has potential impacts on crop safety from hazardous microbes. Thus, it is imperative to better understand the impacts of these changes, so we can keep the stakeholders best informed.

What is the future for research and innovation in this area?

Microbiome approaches have enhanced our understanding of microbial communities in every conceivable host, habitat and environmental niche. This now needs to be followed with functional analysis. However, it is important not to lose sight of rare or transient members of the microbiome, which require targeted approaches to be done in parallel. As we increase our understanding of soil health, we believe this will have real benefits for crop quality and safety.

About the author
Nicola Holden
© Nicola Holden

Professor Nicola Holden is based in the Rural Land Use Department at Scotland’s Rural College (SRUC), Aberdeen, UK, and is a member of the Microbiology Society. This case study was written on behalf of an EU COST Action, HuPlantControl. The COST (European Cooperation in Science and Technology) Actions aim to build networks of expertise across EU member states to address strategically relevant and contemporary questions. Find out more about HuPlantControl.