Earth’s climate is undergoing adverse global changes as a result of increasing anthropogenic emissions of greenhouse gases. Climate representing the most important agroecosystem factor influencing the life cycle stages of fungi and their ability to colonize crops, survive, and produce toxins, a shift in their geographical distribution and in the pattern of mycotoxin occurrence is expected.
During the first international conferences on mycotoxins in the 1970s, sessions largely focused on aflatoxins, and the attention was on their control (due to the early understanding that eradication was not possible), their carry-over and the decontamination of mycotoxins. More than 50 years later, there are still a number of burning topics arising, such as the identification and use of suitable biomarkers to evaluate the human and animal’s exposure to mycotoxins, the efficacy of detoxifiers in animal husbandry or the new rapid screening analytical method by NIR.
Previous years’ experience and predictive models benefitting from the newest techniques (transcriptomics, microarray, qPCR) help evaluating the relationship between environmental stressors and biochemical processes regulating mycotoxin production.
With hotter temperatures, A. flavus (aflatoxin producer) is predicted to outcompete A. carbonarius (ochratoxin producer) and Penicillium spp. (OTA and PAT producers).
Recently in South and Eastern Europe, years with hotter and drier weather than usual influenced fungi growth in crops, with higher occurrence of A. flavus to the detriment of Fusarium spp. This correlates a higher incidence of aflatoxin contamination in this region, not previously considered at risk for aflatoxins. Some models predict an increase (up to 50%) of AFM1 occurrence in milk by 2030.
Meanwhile in South, Central and Southeast Asia, higher rainfall resulted in high AFB1 levels.
Fusarium tolerate a wide range of temperatures and require high water activity (aw) to develop. Thus, their occurrence (F. graminearum in particular) may increase in Central and North Europe, which is expected to be more humid until 2050.
Increased CO2 level is predicted to increase by 2.5 times Fusarium biomass, without impacting mycotoxin production. Meanwhile, fumonisin growth is strictly related to weather conditions, and recent climate variability influences their distribution, as observed with an increase in Central Europe.
Overall, evidence suggests that climate change will negatively affect crops worldwide in terms of loss of suitable cultivation areas, resulting in increased susceptibility to fungal contamination and an increase in mycotoxin contamination. Yet, further research is needed to obtain a more comprehensive view of the effects of climate change on fungi and mycotoxins occurrence.
Reference: Zingales et al., 2022. Climate Change and Effects on Molds and Mycotoxins. Toxins, 14, 445. https://doi.org/10.3390/toxins14070445.
