Interacting climate change environmental factors effects on Fusarium langsethiae growth, expression of Tri genes and T-2/HT-2 mycotoxin production on oat-based media and in stored oats

Machine Learning Applied to the Detection of Mycotoxin in Food: A Systematic Review

Mycotoxins, toxic secondary metabolites produced by certain fungi, pose significant threats to global food safety and public health. These compounds can contaminate a variety of crops, leading to economic losses and health risks to both humans and animals. Traditional lab analysis methods for mycotoxin detection can be time-consuming and may not always be suitable for large-scale screenings. However, in recent years, machine learning (ML) methods have gained popularity for use in the detection of mycotoxins and in the food safety industry in general due to their accurate and timely predictions. We provide a systematic review on some of the recent ML applications for detecting/predicting the presence of mycotoxin on a variety of food ingredients, highlighting their advantages, challenges, and potential for future advancements. We address the need for reproducibility and transparency in ML research through open access to data and code. An observation from our findings is the frequent lack of detailed reporting on hyperparameters in many studies and a lack of open source code, which raises concerns about the reproducibility and optimisation of the ML models used. The findings reveal that while the majority of studies predominantly utilised neural networks for mycotoxin detection, there was a notable diversity in the types of neural network architectures employed, with convolutional neural networks being the most popular.

Manipulating atmospheric CO2 concentration induces shifts in wheat leaf and spike microbiomes and in Fusarium pathogen communities

Changing atmospheric composition represents a source of uncertainty in our assessment of future disease risks, particularly in the context of mycotoxin producing fungal pathogens which are predicted to be more problematic with climate change. To address this uncertainty, we profiled microbiomes associated with wheat plants grown under ambient vs. elevated atmospheric carbon dioxide concentration [CO2] in a field setting over 2 years. We also compared the dynamics of naturally infecting versus artificially introduced Fusarium spp. We found that the well-known temporal dynamics of plant-associated microbiomes were affected by [CO2]. The abundances of many amplicon sequence variants significantly differed in response to [CO2], often in an interactive manner with date of sample collection or with tissue type. In addition, we found evidence that two strains within Fusarium - an important group of mycotoxin producing fungal pathogens of plants - responded to changes in [CO2]. The two sequence variants mapped to different phylogenetic subgroups within the genus Fusarium, and had differential [CO2] responses. This work informs our understanding of how plant-associated microbiomes and pathogens may respond to changing atmospheric compositions.

Diversity of Fusarium Species and Their Mycotoxins in Cereal Crops from the Asian Territory of Russia

Up-to-date information on the occurrence of Fusarium fungi and their mycotoxins in the grain of wheat, barley and oats grown in the Urals and West Siberia in 2018‒2019 is presented. Mycological analysis of grain revealed at least 16 species of Fusarium fungi. The F. sporotrichioides, F. avenaceum, F. poae, and F. anguioides were predominant, and the proportions of these species among all Fusarium fungi found in the grain were 31, 20, 19, and 13%, respectively. Fusarium graminearum and its mycotoxin deoxynivalenol (DON) are often occurred in grain mycobiota of cereal crops on the territory of both the Urals and West Siberia. New records of fungal species that are rare in the Asian territory of Russia were detected: F. langsethiae and F. sibiricum, which are mainly producers of type A trichothecene mycotoxins, were found in the Kurgan and Kemerovo regions, respectively. In addition, F. globosum that is able to produce fumonisins was detected in Altai Krai and Omsk region. The diversity of Fusarium species was higher in wheat and barley grain samples than in oats. The HPLC-MS/MS method was used to analyse the content of 19 mycotoxins produced by Fusarium fungi. The highest diversity of mycotoxins was found in wheat grain (maximum 12), compared with oats (9) and barley (8). The T-2 and HT-2 toxins, DON, nivalenol, moniliformin (MON) and beauvericin (BEA) occurred more often in the grain samples, compared with other mycotoxins, but their amounts varied significantly, depending on the weather conditions in sampling year and the plant species. The average content of DON (maximum amount was 375 µg/kg) in wheat grain was 5 times higher than its average content in barley grain, and this mycotoxin was not detected in oat grain. The contamination with T-2 and HT-toxins (maximum amounts were 2652 μg/kg and 481 μg/kg, respectively), as well as with BEA (maximum amount was 49 μg/kg) was typical for barley and oat grain samples. The content of MON (maximum amount was 50 μg/kg) in the grain of three different small grain cereals was similar.

Seasonal Diversity and Occurrence of Filamentous Fungi in Smallholder Dairy Cattle Feeds and Feedstuffs in South Africa

This study investigated 65 (35 in summer and 30 in winter) smallholder dairy cattle feeds from Free State and Limpopo provinces in South Africa from 2018 to 2019 for fungal contamination and assessed the impacts of seasonal variation on fungal contamination levels, isolation frequency, and diversity. Samples were examined for fungal contamination using macro- and microscopic approaches, and their identities were confirmed by molecular means. A total of 217 fungal isolates from 14 genera, including Aspergillus, Fusarium, and Penicillium, were recovered from feeds from both seasons. The most prevalent fungal species recovered were A. fumigatus and P. crustosum. Mycological analyses showed that 97% of samples were contaminated with one or more fungal isolates, with the summer fungal mean level (6.1 × 103 to 3.0 × 106 CFU/g) higher than that of feeds sampled during winter (mean level: 1.1 × 103 to 4.1 × 105 CFU/g). Independent sample t-test revealed that the isolation frequencies of the genera Aspergillus and Fusarium were significantly (p ≤ 0.05) higher in summer than winter, while Penicillium prevalence in both seasons was not statistically (p > 0.05) different. Furthermore, the Shannon−Weiner diversity index (H′) revealed a higher fungal diversity in summer (H′ = 2.8) than in winter (H′ = 2.1). This study on fungal contamination could be used for future fungal control and mycotoxin risk management in South Africa.

Interacting Environmental Stress Factors Affect Metabolomics Profiles in Stored Naturally Contaminated Maize

There is interest in understanding the relationship between naturally contaminated commodities and the potential for the production of different useful and toxic secondary metabolites (SMs). This study examined the impact of interacting abiotic stress parameters of water availability and temperature of stored naturally contaminated maize on the SM production profiles. Thus, the effect of steady-state storage water activity (aw; 0.80−0.95) and temperature (20−35 °C) conditions on SM production patterns in naturally contaminated maize was examined. The samples were analysed using Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) to evaluate (a) the total number of known SMs, (b) their concentrations, and (c) changes under two-way interacting environmental stress conditions. A total of 151 metabolites were quantified. These included those produced by species of the Aspergillus, Fusarium and Penicillium genera and other unspecified ones by other fungi or bacteria. There were significant differences in the numbers of SMs produced under different sets of interacting environmental conditions. The highest total number of SMs (80+) were present in maize stored at 20−25 °C and 0.95 aw. In addition, there was a gradation of SM production with the least number of SMs (20−30) produced under the driest conditions of 0.80 aw at 20−30 °C. The only exception was at 35 °C, where different production patterns occurred. There were a total of 38 Aspergillus-related SMs, with most detected at >0.85 aw, regardless of the temperature in the 50−500 ng/g range. For Fusarium-related SMs, the pattern was different, with approx. 10−12 SMs detected under all aw × temperature conditions with >50% produced at 500 ng/g. A total of 40−45 Penicillium-related SMs (50−500 ng/g) were detected in the stored maize but predominantly at 20−25 °C and 0.95 aw. Fewer numbers of SMs were found under marginal interacting abiotic stress storage conditions in naturally contaminated maize. There were approx. eight other known fungal SM present, predominantly in low concentrations (<50 ng/g), regardless of interacting abiotic conditions. Other unspecified SMs present consisted of <20 in low concentrations. The effect of interacting abiotic stress factors for the production of different suites of SMs to take account of the different ecological niches of fungal genera may be beneficial for identifying biotechnologically useful SMs.

Effect of Acclimatization in Elevated CO2 on Growth and Aflatoxin B1 Production by Aspergillus flavus Strains on Pistachio Nuts

There is little knowledge of the effect of acclimatization of Aspergillus flavus strains to climate-related abiotic factors and the subsequent effects on growth and aflatoxin B₁ (AFB₁) production. In this study, two strains of A. flavus (AB3, AB10) were acclimatized for five generations in elevated CO₂ (1000 ppm × 37 °C) on a milled pistachio-based medium. A comparison was made of the effects of non-acclimatized strains and those that were acclimatized when colonizing layers of pistachio nuts exposed to 35 or 37 °C, 400 or 1000 ppm CO₂, and 0.93 or 0.98 water activity (a_w), respectively. Acclimatization influenced the fitness in terms of the growth of one strain, while there was no significant effect on the other strain when colonizing pistachio nuts. AFB₁, production was significantly stimulated after ten days colonization when comparing the non-acclimatized and the acclimatized AB3 strain. However, there was no significant increase when comparing these for strain AB10. This suggests that there may be inter-strain differences in the effects of acclimatization and this could have a differential influence on the mycotoxin contamination of such commodities.

Survey of mycotoxins in milling oats dedicated for food purposes between 2013 and 2019 by LC-MS/MS

Although the common oat (Avena sativa L.) is well known for its nutritional benefits, it carries the risk of contamination with mycotoxins due to its susceptibility to the growth of various fungi. The procurement of milling oats for food could become more difficult in the coming harvest years due to limited availability, specific quality requirements and the avoidance of mycotoxin contamination. In light of ongoing discussions in the European Commission on regulatory limits for certain mycotoxins including their modified forms, the purpose of this study was to improve the database on their occurrence in milling oats. In particular, we provide data on the predominantly occurring trichothecenes such as deoxynivalenol and its acetylated and modified derivatives (e.g. 3-acetyl-deoxynivalenol, 15-acetyl-deoxynivalenol and deoxynivalenol-3-glucoside) as well as on T-2 and HT-2 toxins. Additionally, the following mycotoxins were analysed: zearalenone, nivalenol, diacetoxyscirpenol, fusarenon-X, ochratoxin A, sterigmatocystin and aflatoxins B₁, B₂, G₁ and G₂. Oat samples, (n = 281) pre-selected for their physical properties and DON-content to be less than 1750 µg/kg from 11 European provenances, were analysed for 16 different mycotoxins by LC-MS/MS. Samples were collected from the years of harvest 2013 to 2019. High incidence rates above the limit of quantification of either 5 µg/kg for T-2 and HT-2 toxins or 10 µg/kg for deoxynivalenol were found (98.1, 94.7 and 91.4%, respectively). The mean concentration of the sum of T-2 and HT-2 toxins was 149 µg/kg. The highest level was found in an Irish sample containing 1290 µg/kg for the sum of T-2 and HT-2 toxins. The mean deoxynivalenol concentration was 289 µg/kg, while the highest level was 1414 µg/kg in a Swedish sample. Besides nivalenol other mycotoxins were only present in trace concentrations or not detected.

Intra-species variability in Fusarium langsethiae strains in growth and T-2/HT-2 mycotoxin production in response to climate change abiotic factors

The objective of this study was to evaluate the potential intra-species variability of 3 Fusarium langsethiae strains in response to extreme climate change (CC) conditions on an oat-based matrix. The impact of elevated temperature (25 vs 30-34 °C) coupled with increasing drought stress (0.98 vs 0.95 aw) and elevated CO2 (400 vs 1000 ppm) were examined on lag phases prior to growth, growth rate, and production of the mycotoxins T-2 and HT-2 and their ratio. In comparison to the control conditions (25 °C; 0.98; 400 ppm), exposure to increased temperature (30-34 °C), showed similar reductions in the lag phase and fungal growth rates of all 3 strains. However, with elevated CO2 a reduction in both lag phases prior to growth and growth rate occurred regardless of the aw examined. For T-2 and HT-2 mycotoxin production, T-2 showed the most intra-species variability in response to the interacting abiotic stress factors, with the 3 strains having different environmental conditions for triggering increases in T-2 production: Strain 1 produced higher T-2 toxin at 25 °C, while Strain 2 and the type strain (Fl201059) produced most at 0.98 aw/30 °C. Only Strain 2 showed a reduction in toxin production when exposed to elevated CO2. HT-2 production was higher at 25 °C for the type strain and higher at 30-34 °C for the other two strains, regardless of the aw or CO2 level examined. The HT-2/T-2 ratio showed no significant differences due to the imposed interacting CC abiotic conditions.

Impacts of Climate Change Interacting Abiotic Factors on Growth, aflD and aflR Gene Expression and Aflatoxin B1 Production by Aspergillus flavus Strains In Vitro and on Pistachio Nuts

Pistachio nuts are an important economic tree nut crop which is used directly or processed for many food-related activities. They can become colonized by mycotoxigenic spoilage fungi, especially Aspergillus flavus, mainly resulting in contamination with aflatoxins (AFs), especially aflatoxin B₁ (AFB₁). The prevailing climate in which these crops are grown changes as temperature and atmospheric CO₂ levels increase, and episodes of extreme wet/dry cycles occur due to human industrial activity. The objectives of this study were to evaluate the effect of interacting Climate Change (CC)-related abiotic factors of temperature (35 vs. 37 °C), CO₂ (400 vs. 1000 ppm), and water stress (0.98-0.93 water activity, a_w) on (a) growth (b) aflD and aflR biosynthetic gene expression and (c) AFB₁ production by two strains A. flavus (AB3, AB10) in vitro on milled pistachio-based media and when colonizing layers of shelled raw pistachio nuts. The A. flavus strains were resilient in terms of growth on pistachio-based media and the colonisation of pistachio nuts with no significant difference when exposed to the interacting three-way climate-related abiotic factors. However, in vitro studies showed that AFB₁ production was significantly stimulated (p < 0.05), especially when exposed to 1000 ppm CO₂ at 0.98-0.95 a_w and 35 °C, and sometimes in the 37 °C treatment group at 0.98 a_w. The relative expression of the structural aflD gene involved in AFB₁ biosynthesis was decreased or only slightly increased, relative to the control conditions at elevated CO, regardless of the a_w level examined. For the regulatory aflR gene expression, there was a significant (p < 0.05) increase in 1000 ppm CO₂ and 37 °C for both strains, especially at 0.95 a_w. The in situ colonization of pistachio nuts resulted in a significant (p < 0.05) stimulation of AFB₁ production at 35 °C and 1000 ppm CO₂ for both strains, especially at 0.98 a_w. At 37 °C, AFB₁ production was either decreased, in strain AB3, or remained similar, as in strain AB10, when exposed to 1000 ppm CO₂. This suggests that CC factors may have a differential effect, depending on the interacting conditions of temperature, exposure to CO₂ and the level of water stress on AFB₁ production.

Water and temperature relations of Fusarium langsethiae strains and modelling of growth and T-2 and HT-2 mycotoxin production on oat-based matrices

In the UK and Northern Europe, ripening oats can become contaminated with T-2 and HT-2 mycotoxins, produced mainly by Fusarium langsethiae. There are indicative levels related to the maximum limits for oat grain for these toxins. The objectives of this study were to examine the effect of interacting conditions of temperature (10-30 °C) and water activity (a_w, 0.995-0.90) on (a) lag times prior to growth, (b) growth and (c) T-2 and HT-2 toxins by two strains of F. langsethiae isolated from oats in the UK and compare this with the type strain (Fl201059) which has been genomically sequenced, and (d) develop (and validated with published data) a probabilistic models for impacts of temperature × a_w on growth and toxin production. All three strains had an optimum a_w range and temperature of 0.995-0.98 and 25 °C for growth. For T-2 + HT-2 production these were 0.995 a_w and 20 °C. Overall, the type strain produced higher amounts of T-2 + HT-2 with a HT-2/T-2 ratio of up to 76. Using this study data sets and those from the literature, probabilistic models were developed and validated for growth and T-2 + HT-2 toxin production in relation to temperature × a_w conditions. These models, when applied in stored oats, will be beneficial in determining the conditions on the relative level of risk of contamination with these two toxins in the context of the EU indicative maximum levels.

Natural Co-Occurrence of Multiple Mycotoxins in Unprocessed Oats Grown in Ireland with Various Production Systems

The natural co-occurrence of 42 mycotoxins was investigated in unprocessed oat grains grown in Ireland. The sample set included a total of 208 oat crops harvested during 2015–2016 and produced using conventional, organic, or gluten free farming systems. A range of different toxins was identified, including the major type A (neosolaniol, HT-2 and T-2 toxins, T-2 triol, and T-2-glucoside, co-occurring in 21 samples) and B trichothecenes (deoxynivalenol, nivalenol, and deoxynivalenol-3-glucoside), enniatins (B1, B, and A1, co-occurring in 12 samples), as well as beauvericin, alternariol, mycophenolic acid, and sterigmatocystin. The influences of sowing season, year, and production system were investigated, eventually indicating that the latter factor may have a higher impact than others on the production of certain mycotoxins in oats. The most frequently quantified compounds were HT-2 (51%) and T-2 (41%) toxins, with gluten free oats containing significantly lower concentrations of HT-2 compared to conventionally produced oats. Although the prevalence and concentrations of mycotoxin found in oat samples in this study should be substantially reduced by processing. However, as mycotoxin occurrence is clearly influenced by multiple factors, controlled field trials should be carried out to define optimal agronomic practices and mitigate mycotoxin production. Furthermore, this work highlights the need for regularly testing cereal-based foods with multi-residue analytical methods with wider specificities than the traditionally screened and regulated toxins, to generate knowledge on the occurrence of several mycotoxins that are, to date, rarely investigated.

Toxigenic Fungi and Mycotoxins in a Climate Change Scenario: Ecology, Genomics, Distribution, Prediction and Prevention of the Risk

Toxigenic fungi and mycotoxins are very common in food crops, with noticeable differences in their host specificity in terms of pathogenicity and toxin contamination. In addition, such crops may be infected with mixtures of mycotoxigenic fungi, resulting in multi-mycotoxin contamination. Climate represents the key factor in driving the fungal community structure and mycotoxin contamination levels pre- and post-harvest. Thus, there is significant interest in understanding the impact of interacting climate change-related abiotic factors (especially increased temperature, elevated CO2 and extremes in water availability) on the relative risks of mycotoxin contamination and impacts on food safety and security. We have thus examined the available information from the last decade on relative risks of mycotoxin contamination under future climate change scenarios and identified the gaps in knowledge. This has included the available scientific information on the ecology, genomics, distribution of toxigenic fungi and intervention strategies for mycotoxin control worldwide. In addition, some suggestions for prediction and prevention of mycotoxin risks are summarized together with future perspectives and research needs for a better understanding of the impacts of climate change scenarios.

Resilience of Aspergillus westerdijkiae Strains to Interacting Climate-Related Abiotic Factors: Effects on Growth and Ochratoxin A Production on Coffee-Based Medium and in Stored Coffee

We examined the resilience of strains of Aspergillus westerdijkiae in terms of growth and ochratoxin A (OTA) production in relation to: (a) two-way interacting climate-related abiotic factors of water activity (aw, 0.99-0.90) × temperature (25-37 °C) on green coffee and roasted coffee-based media; (b) three-way climate-related abiotic factors (temperature, 30 vs. 35 °C; water stress, 0.98-0.90 aw; CO2, 400 vs. 1000 ppm) on growth and OTA production on a 6% green coffee extract-based matrix; and (c) the effect of three-way climate-related abiotic factors on OTA production in stored green coffee beans. Four strains of A. westerdijkiae grew equally well on green or roasted coffee-based media with optimum 0.98 aw and 25-30 °C. Growth was significantly slower on roasted than green coffee-based media at 35 °C, regardless of aw level. Interestingly, on green coffee-based media OTA production was optimum at 0.98-0.95 aw and 30 °C. However, on roasted coffee-based media very little OTA was produced. Three-way climate-related abiotic factors were examined on two of these strains. These interacting factors significantly reduced growth of the A. westerdijkiae strains, especially at 35 °C × 1000 ppm CO2 and all aw levels when compared to 30 °C. At 35 °C × 1000 ppm CO2 there was some stimulation of OTA production by the two A. westerdijkiae strains, especially under water stress. In stored green coffee beans optimum OTA was produced at 0.95-0.97 aw/30 °C. In elevated CO2 and 35 °C, OTA production was stimulated at 0.95-0.90 aw.

Unveiling the effect of interacting forecasted abiotic factors on growth and aflatoxin B1 production kinetics by Aspergillus flavus

The aim was to decipher the temporal impact of key interacting climate change (CC) abiotic factors of temperature (30 vs 37 °C), water activity (a_w; 0.985 vs 0.930) and CO₂ exposure (400 vs 1000 ppm) on (a) growth of Aspergillus flavus and effects on (b) gene expression of a structural (aflD) and key regulatory gene (aflR) involved in aflatoxin B₁ (AFB₁) biosynthesis and (c) AFB₁ production on a yeast extract sucrose medium over a period of 10 days. A. flavus grew and produced AFB₁ very early with toxin detected after only 48 h. Both growth and toxin production were significantly impacted by the interacting abiotic factors. The relative expression of the aflD gene was significantly influenced by temperature; aflR gene expression was mainly modulated by time. However, no clear relationship was observed for both genes with AFB₁ production over the experimental time frame. The optimum temperature for AFB₁ production was 30 °C. Maximum AFB₁ production occurred between days 4-8. Exposure to higher CO₂ conditions simulating forecasted CC conditions resulted in the amount of AFB₁ produced in elevated temperature (37 °C) being higher than with the optimum temperature (30 °C) showing a potential for increased risk for human/animal health due to higher accumulation of this toxin.

Interacting climate change factors (CO2 and temperature cycles) effects on growth, secondary metabolite gene expression and phenotypic ochratoxin A production by Aspergillus carbonarius strains on a grape-based matrix

Little is known on the impact that climate change (CC) may have on Aspergillus carbonarius and Ochratoxin A (OTA) contamination of grapes, especially in the Mediterranean region where in CC scenarios temperature are expected to increase by +2-5 °C and CO₂ from 400 to 800/1200 ppm. This study examined the effect of (i) current and increased temperature in the alternating 11.5 h dark/12.5 h light cycle (15-28 °C vs 18-34 °C), representative of the North Apulia area, South Italy and (ii) existing and predicted CO₂ concentrations (400 vs 1000 ppm), on growth, expression of biosynthetic genes (AcOTApks, AcOTAnrps, AcOTAhal, AcOTAp450, AcOTAbZIP) and regulatory genes of Velvet complex (laeA/veA/velB, "velvet complex") involved in OTA biosynthesis and OTA phenotypic production by three strains of A. carbonarius. The experiments made on a grape-based matrix showed that elevated CO₂ resulted in a general stimulation of growth and OTA production. These results were also supported by the up-regulation of both structural and regulatory genes involved in the OTA biosynthesis. Our work has shown for the first time that elevated CO₂ concentration in the Mediterranean region may result in an increased risk of OTA contamination in the wine production chain.

Resilience of Biocontrol for Aflatoxin Minimization Strategies: Climate Change Abiotic Factors May Affect Control in Non-GM and GM-Maize Cultivars

There has been significant interest in the development of formulations of non-toxigenic strains of Aspergillus flavus for control of toxigenic strains to reduce the aflatoxin B₁ (AFB₁) contamination of maize. In the future, climate change (CC) abiotic conditions of temperature (+2–4°C), CO₂ (existing levels of 400 vs. 800–1,200 ppb), and drought stress will impact on the agronomy and control of pests and diseases. This study has examined (1) the effect of two-way interacting factors of water activity × temperature on colonization and AFB₁ contamination of maize cobs of different ripening ages; (2) the effect of non-toxigenic strains of A. flavus (50:50 inoculum ratio) on relative control of toxigenic A. flavus and AFB₁ contamination of ripening cobs; (3) post-harvest control of AFB₁ by non-toxigenic strains of A. flavus in non-GM and isogenic GM maize cultivars using the same inoculum ratio; and (4) the impact of three-way interacting CC factors on relative control of AFB₁ in maize cobs pre-harvest and in stored non-GM/GM cultivars. Pre-harvest colonization and AFB₁ production by a toxigenic A. flavus strain was conserved at 37°C when compared with 30°C, at the three ripening stages of cob development examined: milk ripe (R3), dough (R4), and dent (R5). However, pre-harvest biocontrol with a non-toxigenic strain was only effective at the R3 and R4 stages and not at the R5 stage. This was supported by relative expression of the aflR regulatory biosynthetic gene in the different treatments. When exposed to three-way interacting CC factors for control of AFB₁ pre-harvest, the non-toxigenic A. flavus strain was effective at R3 and £4 stages but not at the R5 stage. Post-harvest storage of non-GM and GM cultivars showed that control was achievable at 30°C, with slightly better control in GM-cultivars in terms of the overall inhibition of AFB₁ production. However, in stored maize, the non-toxigenic strains of A. flavus had conserved biocontrol of AFB₁ contamination, especially in the GM-maize cultivars under three-way interacting CC conditions (37°C × 1,000 ppm CO₂ and drought stress). This was supported by the relative expression of the aflR gene in these treatments. This study suggests that the choice of the biocontrol strains, for pre- or post-harvest control, needs to take into account their resilience in CC-related abiotic conditions to ensure that control of AFB₁ contamination can be conserved.

The fungal threat to global food security

Fungi threaten the security of food supply to human populations on several fronts. They destroy up to 30 % of crop products through disease and spoilage processes, while mycotoxin-producing fungi and opportunistic pathogens endanger food safety. Control of these fungi is vital for improving food security, but current measures are inadequate and further challenges due to human-population growth and climate change are escalating. Investment and innovation in research on strategies to control fungal growth, harnessed through international, inter-disciplinary collaboration across socio-economic boundaries, provides one key to rising to this challenge.