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Assessments of potential toxin production of biological control agents are unnecessary harsh in the EU

Published: 17 September 2019

The introduction of microbial control agents into the European market for practical use in pest and disease control is a very slow and costly process. This is partly due to unnecessarily strict regulations as metabolites from microorganisms has been assessed in the same way as metabolites from synthetic sources. In a new article, recommendations are given for new risk assessments in the EU that will benefit all stakeholders.

The use of antagonistic and entomopathogenic microorganisms for biological control of pests and diseases has been slower in the EU than in other comparable jurisdictions. This is due to the strict regulatory requirements.

– We investigated the history behind the adoption of the concept “relevant metabolite” into the data requirements and risk assessment of microbial control agents, says Ingvar Sundh.

Where do EU evaluations of metabolites of microbials fail?

Part of the problem is the difficulty to properly distinguish between degradation products, referred to as ‘metabolites’, of a pesticide and secondary metabolites of microorganisms. Today, regulatory experts are encouraged to view any metabolite of a microorganism as comparable to a degradation product, or ‘metabolite’, of a chemical pesticide.

– This view has led to complicated discussions and unnecessary lengthy approval processes. Today, there is confusion on how to best evaluate potential production of harmful substances by microbial control agents, says Ingvar.

Identifying key issues and concerns

Therefore, a team of researchers from the Netherlands, UK, Denmark and Sweden has examined the EU regulatory perspective on metabolites of microbial control agents for plant protection. Some key issues and concerns were identified.

In the article, that was presented at the conference SIP/IOBC in Spain this summer, the authors suggest that the EU data requirements should be revised. New definitions are required which distinguish between metabolites and breakdown products from either microbial or synthetic sources.

– We also suggest implementation of a basic hazard assessment. If a biological control agent passes this assessment without any concerns, the production of unknown, potentially harmful, substances do not need to be further investigated, concludes Ingvar, who is one of the authors behind the paper.


Microbial secondary metabolites have many ecological functions, for example:

  • Antimicrobial activity - compete with other microbes
  • Facilitate nutrient uptake
  • Sporulation and germination
  • Signalling (e.g. quorum sensing)
  • Semiochemicals – attract/repel invertebrates
  • Promote plant growth
  • Virulence and pathogenicity

Secondary metabolites are an integral part of a microorganisms’ survival strategy in the environment.


Ingvar Sundh

Professor at the Department of Molecular Sciences

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