Biofilms in the UK food sector

Biofilms are present throughout the UK food chain, from farm to fork, and can have both beneficial and harmful effects on public health and the economy. While some biofilms contribute positively to soil health and crop resilience, others pose significant risks by harbouring pathogens, contaminating food surfaces, and reducing equipment efficiency. Effective management, control, or prevention of biofilms across the food sector are therefore essential to ensure food safety and maintain production standards. Microorganisms must be considered at every stage of the food cycle, from primary production and processing to distribution and domestic use, with the impacts on the UK economy estimated at over £8 Bn annually .

Crop Production

Biofilms play a dual role in crop production. Beneficially, biofilm-forming microbes enhance soil fertility, improve nutrient uptake, and promote plant resilience by acting as biofertilisers or biocontrol agents against pathogens. They stabilise soil ecosystems and support sustainable agriculture. Biofilms can also have negative implications such as harbouring plant pathogens, clogging irrigation systems, and contributing to the persistence and spread of antimicrobial resistance. The presence of biofilms on crop surfaces pre-harvest may pose food safety risks.

Animal Farming

In animal farming, biofilms have potential beneficial uses for supporting overall animal health. Biofilm-based probiotics and microbial treatments can aid digestion, improve immunity, enhance waste breakdown, and reduce odours in animal housing. While biofilms are not deliberately “used” by most livestock farmers, practices that harness biofilm-forming microbes are beginning to emerge, particularly in the areas of probiotic supplementation and waste management. Unmanaged biofilms pose risks by harbouring pathogens in water lines, feeding systems, and surfaces, contributing to disease transmission and reduced hygiene. They can also facilitate the persistence and spread of antimicrobial resistance.

Food Production and Processing

In food processing, biofilms can offer controlled benefits in specific applications such as fermentation, where biofilm-forming microbes contribute to flavour development and product stability in items like cheese, yoghurt, and fermented vegetables. Biofilms in food production and processing plants can also pose a serious risk to food safety, product quality, and operational efficiency. They can harbour pathogens such as Listeria, Salmonella, and E. coli, leading to contamination and potential outbreaks. Biofilms are highly resistant to standard cleaning and disinfection, making them difficult to remove once established. Their presence can result in equipment damage, increased maintenance costs, reduced shelf life, product recalls or production shutdowns. In food packaging, biofilms can be beneficial when used in the form of antimicrobial coatings or active packaging materials that incorporate biofilm-forming probiotic or antimicrobial microbes. These innovations can help extend shelf life, prevent spoilage, and reduce reliance on chemical preservatives. However, unintended or unmanaged biofilm formation on packaging equipment or surfaces poses significant risks. Pathogenic or spoilage organisms within biofilms can contaminate products, compromise hygiene, and reduce shelf life. Their resistance to cleaning increases the risk of persistent contamination and regulatory non-compliance.

Retail

In the retail sector, probiotic-based cleaning solutions containing species such as Bacillus subtilis are used. They outcompete harmful bacteria, colonising surfaces that are in contact with food. Biofilms break down dirt and consume organic matter that pathogens thrive on, improving hygiene standards and reducing the risk of infection.Unmanaged biofilms form on surfaces in shops where food is stored, including shelves, display cases and refrigerators. This can lead to transmission to food, particularly as pathogens such as Listeria monocytogenes can survive at low temperatures and have long incubation times. This causes product spoilage and reduced shelf life, leading to foodborne illness, financial losses and reputational damage.

Food Service and Hospitality

Novel disinfectant products that contain probiotic biofilms have been developed and used in the food service and hospitality sector. These include floor and drain cleaning formulations, as well as dishwasher tablets, that contain probiotic species. The disinfectants help reduce odour and promote eco-friendly hygiene.When incorrectly managed, biofilms (including Escherichia coli) form on kitchen surfaces, utensils, plates and kitchen equipment. Catering equipment is in direct contact with food and the consumer, creating a significant threat to public health when contaminated with pathogenic biofilms. High staff turnover, inadequate training on biofilm management and inconsistent hygiene practices all increase the risk of contamination.

Landscape of biofilm regulations and standards

Microbial food safety regulations and standards are important in protecting consumer health from pathogenic outbreaks. The UK’s food safety framework is underpinned by the Food Safety Act 1990 and retained EU regulations. These ensure food safety by regulating food hygiene standards, labelling, testing, traceability and reporting.The UK’s food safety framework lacks specific regulations and standards for biofilm management, relying heavily on general microbial management. Outdated testing protocols and self-governed compliance can hinder food safety, which can lead to food pathogen outbreaks, such as the Listeria monocytogenes outbreak of 2019 across eight NHS hospitals. The Food Standards Agency (FSA) and Food Standards Scotland (FSS) enforce regulation in the UK, with the Department for Environment, Food and Rural Affairs and stakeholders across academia and industry providing support. Post-Brexit, there is an opportunity to revise food safety frameworks to incorporate harmonise biofilm-specific standards and detection methods.

Goals of the Biofilm Alliance in Enhancing regulation and standards

The mission of the Biofilm Alliance in supporting food safety regulation is to strengthen the understanding, management, and regulatory oversight of biofilms across the food sector. We aim to bridge gaps between science, industry, and regulators by promoting standardised methodologies for detecting, controlling, and validating both harmful and beneficial biofilms. This includes supporting the safe utilisation of beneficial biofilm-forming microbes in areas such as food preservation and waste reduction. The Alliance also prioritises awareness-raising and training across the food service and manufacturing sectors, equipping stakeholders with the knowledge and tools needed to manage biofilms effectively and uphold food safety standards.

Food Sector