Mycotoxin-Soil interactions: The role of soil in the biosynthesis, sorption, degradation and biological effects of mycotoxins.

• Applicant: Dr. Katherine Munoz Sepúlveda
• Subject Area: Soil Sciences
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 496549265

Mycotoxins are toxic metabolites produced by filamentous fungi in different environmental matrices, also in the soil. Although mycotoxins are regulated and strategies for prevention, reduction and mitigation have been developed and are continuously applied, mycotoxins do still occur in food commodities so that humans are daily exposed to certain mycotoxins levels. Deoxynivalenol (DON) is a Fusarium mycotoxin widely distributed in food commodities and also frequently observed in biomonitoring studies. The occurrence of DON in food matrices is primarily due a direct production in situ, but also an indirect contamination via plant uptake from soil has been confirmed. The biosynthesis of DON in different matrices is determined by environmental and chemical factors. It has been postulated, that the DON production is the result of a stress mediated response to improve fusaria adaptation under non-favourable conditions. The soil is the main habitat for Fusarium inoculum; moreover DON and related molecules have been detected in agricultural soils. However a link between soil properties and mycotoxin production is still unknown, although current evidence suggests an increase in mycotoxin concentration in soil in response to unfavourable conditions for fusarium growth, for example due to the action of fungicides. Another aspect to consider is that concentrations observed in agricultural soils do not provide information about the source and the conditions for mycotoxin production, nor on additional processes that may affect the residual concentrations. In the same context, it has not yet been investigated whether the observed concentrations are likely to cause biological impact on soils. To understand the contribution of soil to mycotoxin residual levels and effects, a deeper understanding of mycotoxin-soil interaction is needed. This includes investigation on 1) factors promoting mycotoxin biosynthesis for example under stress mediated conditions mimicking scenarios in intensive agriculture, 2) determination of residual concentrations after processes of biotransformation and mobility. Finally, 3) DON has antibacterial and antifungal properties, which may suppose a biological response of the microbiome (abundance, structure and functions) in the presence of certain concentrations. The aim of this proposal is to deeper the understanding about mycotoxin-soil interactions at the levels of biosynthesis in the presence of stressors, fate namely sorption & biotransformation and effects to soil microorganisms. This knowledge will contribute to elucidate factors triggering the production in soil and the processes regulating effective concentrations and they are imperative for further prevention strategies that may consider the soil in the assessment of mycotoxin risks at pre-harvest stages

• DFG Programme: Research Grants