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Mycotoxins are toxins produced by fungi that contaminate many key food crops as they grow in the field and during storage. Specific mycotoxins are produced by different fungi. Each type of fungus and mycotoxin have their own optimal temperatures and water activities for growth and production. The legislative limits for various mycotoxins in foodstuffs to protect human health vary between countries but all commodities have their levels evaluated based on the concentrations from one aggregated grain sample. This approach assumes that the variation in toxin levels is uniform and random without spatial trends. This study investigates the spatial distribution of four mycotoxins (aflatoxin, deoxynivalenol, fumonisin and zearalenone) in bins of clean and dirty corn when stored in an environmental cabinet for two months under different temperature and humidity conditions. The bins of clean and dirty corn each had 12 CO2/humidity/temperature sensors installed in three layers, and samples were extracted for mycotoxin analysis from locations close to each sensor following storage. Using Mann–Whitney U and Kruskal–Wallis H statistical tests, significant differences were found between mycotoxin levels attributable to the different environmental conditions and spatial locations of samples. Variations in aflatoxin and zearalenone concentrations were most pronounced for the range of temperature and humidity conditions chosen. By understanding the patterns of spatial variability in mycotoxin concentrations and identifying zones at high risk of contamination, as well as what conditions are favorable, targeted interventions could be implemented to reduce food waste. This work also has implications for how levels of mycotoxins in foodstuffs are sampled and measured. [ABSTRACT FROM AUTHOR]

Mycotoxins that contaminate grain can cause the devaluation of agricultural products and create health risks for the consumer. Fumonisins are one such mycotoxin. Produced primarily by Fusarium verticillioides (Hypocreales: Nectriaceae) (Nirenberg, 1976) on corn, fumonisins' economic impact can be significant by causing various diseases in livestock if contaminated corn is not monitored and removed from animal feed. Finding safe alternatives to the destruction and waste of contaminated grain and restoring its economic value is needed for a sustainable future. Safe reintroduction into the farm food web may be possible through a consumable intermediary such as insects. This study demonstrates the suitability of the house cricket, Acheta domesticus L. as an alternative protein source in domestic animal feed by quantifying fumonisin B1 (FB1) levels in their subsequent insect meal and frass. Small colonies of 2nd instar A. domesticus were reared to 5th instar adults on nutrient-optimized corn-based diets treated with 4 levels of FB1 from 0 to 20 ppm. Increasing levels of FB1 had no adverse effects on the survivorship or growth of A. domesticus. Insect meals prepared from A. domesticus had significantly lower levels of FB1, at 3%–5% of their respective diets, while frass did not differ significantly from their diet. The successful rearing to adulthood of A. domesticus on fumonisin-contaminated diet paired with lower levels of FB1 in their processed insect meal supports the idea that more sustainable agricultural practices can be developed through remediation of low-value mycotoxin-contaminated grain with safer, higher-value insects as livestock feed components. [ABSTRACT FROM AUTHOR]

The yellow mealworm, Tenebrio molitor, L., can be an important component of the circular economy because of its ability to transform a variety of agricultural wastes and byproducts into valuable livestock feed. Analysis of their ability to endure toxins coupled with their potential to transfer contaminants to higher trophic levels is not complete. Fumonisins, produced primarily by Fusarium verticillioides (Hypocreales: Netriaceae) (Sacc.) Nirenberg (1976), are mycotoxins likely to be encountered by T. molitor in corn and other grain byproducts. Tenebrio molitor larvae were reared on a simulated diet of corn and other grain byproducts treated with a range of maximum recommended fumonisin B1 levels for different livestock feeds. We observed that T. molitor were able to survive, grow, and reduce by excretion and metabolism their retained fumonisin B1 levels by up to 99.7% compared to the diet they consumed. Unknown metabolic processes were inferred from the significantly reduced content of fumonisin B1 in the frass (63.1% to 73.2%) as compared to the diet and by the first report of long-chain acylated fumonisin B1 derivatives in insect frass., (Published by Oxford University Press on behalf of Entomological Society of America 2024.)

Mycotoxins that contaminate grain can cause the devaluation of agricultural products and create health risks for the consumer. Fumonisins are one such mycotoxin. Produced primarily by Fusarium verticillioides (Hypocreales: Nectriaceae) (Nirenberg, 1976) on corn, fumonisins' economic impact can be significant by causing various diseases in livestock if contaminated corn is not monitored and removed from animal feed. Finding safe alternatives to the destruction and waste of contaminated grain and restoring its economic value is needed for a sustainable future. Safe reintroduction into the farm food web may be possible through a consumable intermediary such as insects. This study demonstrates the suitability of the house cricket, Acheta domesticus L., as an alternative protein source in domestic animal feed by quantifying fumonisin B1 (FB1) levels in their subsequent insect meal and frass. Small colonies of 2nd instar A. domesticus were reared to 5th instar adults on nutrient-optimized corn-based diets treated with 4 levels of FB1 from 0 to 20 ppm. Increasing levels of FB1 had no adverse effects on the survivorship or growth of A. domesticus. Insect meals prepared from A. domesticus had significantly lower levels of FB1, at 3%-5% of their respective diets, while frass did not differ significantly from their diet. The successful rearing to adulthood of A. domesticus on fumonisin-contaminated diet paired with lower levels of FB1 in their processed insect meal supports the idea that more sustainable agricultural practices can be developed through remediation of low-value mycotoxin-contaminated grain with safer, higher-value insects as livestock feed components., (Published by Oxford University Press on behalf of Entomological Society of America 2024.)

An isolate of Macrophomina phaseolina from muskmelons ( Cucumis melo )was reported by Dunlap and Bruton to produce red pigment(s) in melons and in culture in the presence of added glycine, alanine, leucine, or asparagine in the medium, but not with some other amino acids and nitrogen-containing compounds. We explored the generality and mechanism of this pigment production response using pathogenic M. phaseolina isolates from soybean plants expressing symptoms of charcoal rot disease. A survey of 42 M. phaseolina isolates growing on Czapek-Dox agar medium supplemented with glycine confirmed pigment production by 71% of isolates at the optimal glycine concentration (10 g/L). Studies in this laboratory have demonstrated that some pathogenic isolates of M. phaseolina produce the mycotoxin (-)-botryodiplodin, which has been reported to react with amino acids, proteins, and other amines to produce red pigments. Time course studies showed a significant positive correlation between pigment and (-)-botryodiplodin production by selected M. phaseolina isolates with maximum production at seven to eight days. Pigments produced in agar culture medium supplemented with glycine, beta-alanine, or other amines exhibited similar UV-vis adsorption spectra as did pigments produced by (±)-botryodiplodin reacting in the same agar medium. In a separate study of 39 M. phaseolina isolates, red pigment production (OD 520 ) on 10 g/L glycine-supplemented Czapek-Dox agar medium correlated significantly with (-)-botryodiplodin production (LC/MS analysis of culture filtrates) in parallel cultures on un-supplemented medium. These results support pigment production on glycine-supplemented agar medium as a simple and inexpensive in-culture method for detecting (-)-botryodiplodin production by M. phaseolina isolates., Competing Interests: The authors declare no conflict of interest.