Aflatoxins (AFs) are toxic secondary metabolites produced mostly by Aspergillus species. AF contamination entering the feed and food chain has been a crucial long-term issue for veterinarians, medicals, agroindustry experts, and researchers working in this field. Although different (physical, chemical, and biological) technologies have been developed, tested, and employed to mitigate the detrimental effects of mycotoxins, including AFs, universal methods are still not available to reduce AF levels in feed and food in the last decades. Possible biological control by bacteria, yeasts, and fungi, their excretes, the role of the ruminal degradation, pre-harvest biocontrol by competitive exclusion or biofungicides, and post-harvest technologies and practices based on biological agents currently used to alleviate the toxic effects of AFs are collected in this review. Pre-harvest biocontrol technologies can give us the greatest opportunity to reduce AF production on the spot. Together with post-harvest applications of bacteria or fungal cultures, these technologies can help us strictly reduce AF contamination without synthetic chemicals.

The toxins produced by Aspergillus flavus can significantly inhibit the use of maize. As a result of climate change, toxin production is a problem not only in tropical and subtropical areas but in an increasing number of European countries, including Hungary. The effect of meteorological factors and irrigation on mould colonization and aflatoxin B1 (AFB1) mycotoxin production by A. flavus were investigated in natural conditions, as well as the inoculation with a toxigenic isolate in a complex field experiment for three years. As a result of irrigation, the occurrence of fungi increased, and toxin production decreased. The mould count of fungi and toxin accumulation showed differences during the examined growing seasons. The highest AFB1 content was found in 2021. The main environmental factors in predicting mould count were temperature (T_avg, T_max ≥ 30 °C, T_max ≥ 32 °C, T_max ≥ 35 °C) and atmospheric drought (RH_min ≤ 40%). Toxin production was determined by extremely high daily maximum temperatures (T_max ≥ 35 °C). At natural contamination, the effect of T_max ≥ 35 °C on AFB1 was maximal (r = 0.560–0.569) in the R4 stage. In the case of artificial inoculation, correlations with environmental factors were stronger (r = 0.665–0.834) during the R2–R6 stages.

As significant fungal pathogens of crops, Fusaria species contaminate various food and feed commodities. Some of the Fusarium spp. secondary metabolites (e.g., trichothecenes, zearalenone, and fumonisins) are widely known toxic molecules (mycotoxins) with chronic and acute effects on humans and animals. The growing demand for safer, pesticide-free food drives us to increase biological control during crop growing. Recent research suggests that lactic acid bacteria (LABs) as biocontrol are the best choice for extenuating Fusarium mycotoxins. Newly isolated LABs were tested as antifungal agents against Fusarium verticillioides, F. graminearum, and F. oxysporum. The characterized and genetically identified LABs belonged to Limosilactobacillus fermentum (SD4) and Lactiplantibacillus plantarum (FCW4 and CB2) species. All tested LABs and their cell-free culture supernatants showed antagonism on the MRS solid medium. The antifungal activity was also demonstrated on surface-sterilized wheat and peanuts. The germination test of corn kernels proved that the LAB strains SD4 and FCW4 significantly (p < 0.05) enhanced root and shoot development in plantlets while simultaneously suppressing the outgrowth of F. verticillioides. Small-scale corn silage fermentation revealed the significant effects of SD4 supplementation (decreased zearalenone, lower mold count, and total reduction of deoxynivalenol) within the mixed populations.

Mycotoxin contaminations in the feed and food chain are common. Either directly or indirectly, mycotoxins enter the human body through the consumption of food of plant and animal origin. Bacteria with a high mycotoxin elimination capability can reduce mycotoxin contamination in feed and food. Four Gram-positive endospore-forming bacteria (Bacillus thuringiensis AMK10/1, Lysinibacillus boronitolerans AMK9/1, Lysinibacillus fusiformis AMK10/2, and Rummeliibacillus suwonensis AMK9/2) were isolated from fermented forages and tested for their deoxynivalenol (DON), aflatoxin B1 (AFB1), and zearalenone (ZEA) elimination potentials. Notably, the contribution of bacterial cell wall fractions to the observed outstanding ZEA elimination rates was demonstrated; however, the ZEA elimination differed considerably within the tested group of Gram-positive bacteria. It is worth noting that the purified cell wall of L. boronitolerans AMK9/1, L. fusiformis AMK10/2 and B. thuringiensis AMK10/1 were highly efficient in eliminating ZEA and the teichoic acid fractions of B. thuringiensis AMK10/1, and L. fusiformis AMK10/2 could also be successfully used in ZEA binding. The ZEA elimination capacity of viable R. suwonensis AMK9/2 cells was outstanding (40%). Meanwhile, R. suwonensis AMK9/2 and L. boronitolerans AMK9/1 cells produced significant esterase activities, and ZEA elimination of the cell wall fractions of that species did not correlate with esterase activity. DON and AFB1 binding capabilities of the tested bacterial cells and their cell wall fractions were low, except for B. thuringiensis AMK10/1, where the observed high 64% AFB1 elimination could be linked to the surface layer (S-layer) fraction of the cell wall.

Several feed preservation methods can ensure lower mycotoxin contamination levels enter the food life cycle, and a relatively common wet preservation method of forage plant materials is fermentation. This study aimed to characterize the microbiological state and mycotoxin contamination of fermented silages and haylages (corn, alfalfa, rye, and triticale), their main microbiota, and isolation of bacteria with mycotoxin resistance. Bacteria that remain viable throughout the fermentation process and possess high mycotoxin resistance can have a biotechnological benefit. Lactic acid bacteria, primarily found in corn silage, were Lactiplantibacillus plantarum isolates. Meanwhile, a high percentage of alfalfa silage and haylage was characterized by Lactiplantibacillus pentosus. In rye silage and haylage samples, Pediococci were the typical bacteria. Bacterial isolates were characterized by deoxynivalenol and zearalenon resistance. Some of them were sensitive to aflatoxin B1, while ochratoxin A caused 33–86% growth inhibition of the cultures. The mycotoxin resistant organisms are under further research, aiming for mycotoxin elimination in feed.

Maize production is increasingly challenged by climate change, which affects plant physiology, fungal colonization, and mycotoxin contamination. Aspergillus flavus, a saprophytic fungus, thrives in warm, dry conditions, leading to aflatoxin B1 (AFB1) accumulation, and posing significant food safety risks. Macro- and micro-climatic factors, including temperature, humidity, and precipitation, influence kernel development, leaf wetness duration, and mycotoxin biosynthesis. Nitrogen availability and irrigation play crucial roles in modulating plant responses to these stressors, affecting chlorophyll content, yield parameters, and fungal interactions. To investigate these interactions, a Completely Randomized Design (CRD) was employed from 2020 to 2022 to assess physiological changes in SY Orpheus maize hybrid under varying climatic conditions. Rising temperatures and declining relative humidity (RH) significantly reduced kernel number per ear length from 25.60 ± 0.34 in 2020 to 17.89 ± 0.39 in 2022 (p < 0.05), impacting yield. The AFB1 levels peaked in 2021 (156.88 ± 59.02 µg/kg), coinciding with lower humidity and increased fungal stress. Water availability improved kernel numbers and reduced AFB1 accumulation (p < 0.05) but did not significantly affect the total fungal load (p > 0.05). Nitrogen supplementation enhanced plant vigor, suppressed AFB1 biosynthesis, and influenced spectral indices. Potential confounding factors such as soil variability and microbial interactions may require further investigations.