Quantification of fungal colonization, sporogenesis, and production of mycotoxins using kernel bioassays.

Malt bagasse is the primary solid waste product from the brewing process, with notable environmental implications. Due to its nutritional value, it has potential as animal feed, primarily through ensilage. Alfalfa pellets can enhance this silage by adding digestible nitrogen and fibre. However, the high moisture content favours microbial contamination, particularly by fungi like Fusarium, which produces harmful mycotoxins. This study evaluated the impact of winter silage on fungal diversity, Fusarium presence, and mycotoxin contamination in malt bagasse, comparing the pre- and post-silage stages with the addition of alfalfa pellets. Results showed a diverse range of fungi, including Mucor, Cladosporium, Fusarium, and Penicillium, as well as yeasts. Fungal contamination was higher before silage, although the addition of alfalfa increased it after silage was produced. Fusarium verticillioides was the most common Fusarium species. Mycotoxin analysis detected DON (1.4 ppb) in only one sample. A two-month winter silage process under cold-temperate conditions appears to reduce fungal contamination and preserve feed quality. These findings support silage as a circular strategy to manage brewery waste safely, but further research and policy measures are needed to minimise biological risks in the brewing and livestock sectors amid climate change.

Determination of Mycotoxins and Characterization of Aflatoxin-Producing Aspergillus Section Flavi in Maize from North-West Nigeria

The growth of filamentous fungi on fodder is recognized as responsible for fungal deterioration and mycotoxin contamination of the plant mass leads to economic losses in the dairy cow production system. Mycotoxin contamination has significant implications for human and animal health and is one of the major concerns in the food and feed chain. This research provides an insight into the variety of viable molds (i.e., filamentous microfungi) that can be isolated from hay produced in South Italy and destined to dairy cows. On different lots of hay (n = 55) collected from 20 dairy farms, a total of 33 different fungal species were identified. The most representative was Cladosporium cladosporioides (n = 46, 84%) followed by Alternaria alternata (n = 25, 45%), and Rhizopus stolonifer (n = 24, 44%). The species most closely related to aflatoxin (AF) contamination, Aspergillus flavus, was often isolated (n = 11, 20%). Regarding AF detection, all the hay samples were found to be scarcely contaminated by AFB1 and showed values from 0.0020 to 0.0077 mg/kg, below the limits established by European Union (EU legislation) (0.02 mg/kg). None of the samples were positive for Aspergillia and tested for AFB1 showed results exceeding established limits. Additionally, hay with moisture between 15.0 and 19.2% or crude ash on dry matter content ranging from 14.0 to 15.5% reported an increased presence of AFB1 (p < 0.05) compared to the other samples. All the analyzed hay samples, besides the presence of molds, can be considered safe for the presence of AFB1. Prevention of mold spoilage is mandatory to reduce the exposure of humans and animals to mycotoxins.

Maize is a possible host of many fungi, some of them able to produce different mycotoxins. Few studies exist on co-occurring fungi and resulting multi-mycotoxin contamination in field; for this reason, in field trials were conducted in two consecutive years to verify fungal incidence and mycotoxin production in the case of the co-occurrence of the three main mycotoxigenic fungi of maize in Italy: Aspergillus flavus, Fusarium verticillioides, and Fusarium graminearum able to produce, respectively, aflatoxin B1 (AFB1), fumonisins (FBs), and deoxynivalenol (DON). Artificial inoculation was done after silk emergence of maize and samples were collected with a 2 week schedule up to harvest time (four samplings). Fungal interaction resulted as playing a role for both fungal incidence and mycotoxins production, as did weather conditions too. Main interactions were noted between A. flavus and F. verticillioides, and between F. verticillioides and F. graminearum. In particular, as a result of fungal co-occurrence, AFB1 resulted stimulated by F. graminearum presence while no effects were noted in FBs and DON in case of F. verticillioides–F. graminearum co-occurrence. Interestingly, the co-presence of A. flavus significantly reduced both FB and DON production.

A total of 89 freshly harvested soybean seed samples (Roundup Ready [transgenic] soybean cultivars) from the 2010/2011 crop season were collected from five locations in the Northern Pampean Region II, Argentina. These samples were analyzed for internal mycoflora, toxin production of isolated fungi, and for a range of mycotoxins. Mycotoxin analysis of aflatoxins (AFs), zearalenone (ZEA), fumonisins (FBs) and ochratoxin A (OTA) was done by HPLC-FLD (high performance liquid chromatography with postcolumn fluorescence derivatization), alternariol and alternariol monomethyl ether with HPLC-UV (HPLC with UV detection), trichothecenes (deoxynivalenol, nivalenol, T-2 toxin, HT-2 toxin, fusarenon X, 3-acetyldeoxynivalenol and 15-acetyldeoxynivalenol were analyzed by GC-ECD (gas chromatography with electron capture detector). Fungal colonization was more frequently found for samples from América, Saladillo and Trenque Lauquen than for samples from General Villegas and Trenel; a total of 1,401 fungal isolates were obtained from the soybean seeds. The most commonly identified fungal genera were Alternaria, Sclerotinia, Chaetomium, Cladosporium, Aspergillus, Penicillium, Phomopsis and Fusarium. Alternaria alternata, A.tenuissima, Aspergillus flavus, Penicillium citrinum, Fusarium verticillioides and F.semitectum were the predominant toxigenic fungal species. Mycotoxin production was confirmed for several isolates of toxigenic species, including Aspergillus flavus, A. parasiticus, Alternaria alternata, A.tenuissima, Fusarium graminearum, F semitectum and F. verticillioides. In particular, the percentage of mycotoxigenic Alternaria alternata (100%), A.tenuissima (95%) and aflatoxigenic strains of A. flavus (57%) were remarkably high. Although none of the mycotoxins, AFs, ZEA, FBs, trichothecenes and OTA, were directly detected in samples of soybean seeds, the frequent presence of toxigenic fungal species indicates the risk of multiple mycotoxin contamination.

Fumonisins in Maize: Can We Reduce Their Occurrence?

Mycotoxigenic fungi such as Fusarium graminearum, Fusarium verticillioides and Stenocarpella maydis infecting maize grain can be detrimental to both humans and animals due to the toxins they produce. Disease management strategies include tillage practices and crop rotations, however, these have not been sufficiently evaluated in South Africa. The effect of cropping systems on ear rot accumulation and mycotoxin contamination in maize grain was investigated in two localities over a four and six-year period. Cropping systems evaluated were: 1) monoculture maize conventional tillage, 2) monoculture maize no-till, 3) two, and 4) three-year rotation systems consisting of maize/cowpea and maize/cowpea/babala (all no-till), respectively. In Buffelsvallei, two additional crop rotations, maize/sunflower and maize/sunflower/babala (all no-till) were included. Naturally infected trials were visually evaluated for disease severity or incidence while fungal and mycotoxin contamination of maize grain was quantified. Disease incidence and mycotoxin contamination were inconsistent throughout the study period due to seasonal and geographical differences. In Buffelsvallei, cropping system had a significant effect (P < 0.05) on the accumulation of fumonisins and F. graminearum for 2010/11, deoxynivalenol (2011/12) and S. maydis incidence (2013/14). Fusarium graminearum and fumonisin accumulation was significantly higher in the three-year maize/cowpea/babala rotation and two-year sunflower rotation in the 2010/11 season, respectively. Deoxynivalenol levels in monoculture maize, using conventional tillage (2011/12) was significantly higher when compared to all other cropping systems and S. maydis incidence was significantly higher in maize conventionally tilled, no-till and two-year maize/cowpea and maize/sunflower cropping systems in the 2013/14 season. Cropping systems had no significant effects on fungal infection or mycotoxin accumulation in maize grain obtained from trials conducted at Erfdeel. The results of this study indicate that Conservation Agriculture systems under the environments evaluated, did not increase the risk of maize ear rots and mycotoxin production.

Maize (Zea mays L.) is one of the main cereals as a source of food, forage and processed products for industry. World production is around 790 million tonnes of maize because as a staple food it provides more than one-third of the calories and proteins in some countries. Stored maize is a man-made ecosystem in which quality and nutritive changes occur because of interactions between physical, chemical and biological factors. Fungal spoilage and mycotoxin contamination are of major concern. Aspergillus and Fusarium species can infect maize pre-harvest, and mycotoxin contamination can increase if storage conditions are poorly managed. Prevention strategies to reduce the impact of mycotoxin in maize food and feed chains are based on using a hazard analysis critical control point systems (HACCP) approach. To reduce or prevent production of mycotoxins, drying should take place soon after harvest and as rapidly as feasible. The critical water content for safe storage corresponds to a water activity (a w) of about 0.7. Problems in maintaining an adequately low a w often occur in the tropics where high ambient humidity make the control of commodity moisture difficult. Damage grain is more prone to fungal invasion and, therefore, mycotoxin contamination. It is important to avoid damage before and during drying, and during storage. Drying maize on the cob before shelling is a very good practice. In storage, many insect species attack grain and the moisture that can accumulate from their activities provides ideal conditions for fungal activity. To avoid moisture and fungal contamination, it is essential that the numbers of insects in stored maize should be kept to a minimum. It is possible to control fungal growth in stored commodities by controlled atmospheres, preservatives or natural inhibitors. Studies using antioxidants, essential oils under different conditions of a w, and temperature and controlled atmospheres have been evaluated as possible strategies for the reduction of fungal growth and mycotoxin (aflatoxins and fumonisins) in stored maize, but the cost of these treatments is likely to remain prohibitive for large-scale use.

The effects of different ecophysiological factors on ochratoxin A production

Fungal and mycotoxins contamination in corn silage: Monitoring risk before and after fermentation

Contamination of Fusarium spp. and mycotoxins at different ear physiological stages of maize in Argentina

This chapter delves into the dynamic field of mycotoxin research and the creative approaches being used to improve food safety by addressing the problems caused by mycotoxigenic fungus. Toxic secondary metabolites pose a serious danger to human health and food security. They are produced by fungi including Aspergillus, Penicillium, and Fusarium species. Because of their prevalence in crops, particularly staple grains like peanuts, wheat, and maize, much study is required to comprehend their methods of development and create practical mitigation measures. Mycotoxin production in fungus is influenced by genetic and metabolic processes that have been clarified by recent advances in mycotoxin research. Designing focused strategies to stop fungal contamination in agricultural contexts requires careful consideration of these observations. Innovative strategies include the creation of biocontrol agents, genetic engineering of crops to increase resistance, and environmentally friendly detoxifying techniques to reduce mycotoxin contamination in food and feed. Additionally, advancements in analytical methods including Mass Spectrometry (MS), biosensors, and High-Performance Liquid Chromatography (HPLC) have transformed the identification and measurement of mycotoxins in a variety of matrices. These delicate techniques are essential for adhering to regulations and guaranteeing that food safety requirements are fulfilled. This chapter also outlines new directions in mycotoxin research, including the effects of global commerce on the regional distribution of mycotoxin contamination and the dynamics of fungal growth and mycotoxin production.

Rice consumption is part of Brazilian food culture, the per capita consumption, considering different forms is approximately of 14.9 kg of rice. The storage of rice grains in inappropriate conditions favor fungal growth and mycotoxin production. A survey was carried out to determine presence of coliforms, Salmonella, Bacillus cereus, fungal and mycotoxin contamination (aflatoxins, ochratoxin A and zearalenone) in 40 rice products (rice flakes and rice dough) samples traded in Terezina. Also, the ability to produce mycotoxins by Aspergillus and Fusarium isolates was shown. Regarding the microbiological standards, the results were within the established pattern. Several fungal species, especially Aspergillus flavus and Penicillium citrinum, were isolates, but the strains were not able to produce aflatoxins and citrinin, respectively. The samples commercialized in Terezina had satisfactory hygienic and sanitary conditions, and free of mycotoxins analyzed. Key words: Rice flakes, rice dough, mycotoxins, fungi, bacteria.

Fungal infection and mycotoxin contamination are major hazards to the safe storage and distribution of foods and feeds consumed by humans and livestock. This study investigated the antifungal and antiaflatoxigenic activities of massoia essential oil (MEO) and its major constituent, C10 massoia lactone (C10), against aflatoxin B (AFB)-producing Aspergillus flavus ATCC 22546. Their antifungal activities were evaluated using a disc diffusion assay, agar dilution method, and a mycelial growth inhibition assay with the AFB analysis using liquid chromatography triple quadrupole mass spectrometry. MEO and C10 exhibited similar antifungal and antiaflatoxigenic activities against A. flavus. C10 was a primary constituent in MEO and represented up to 45.1% of total peak areas analyzed by gas chromatography-mass spectrometry, indicating that C10 is a major compound contributing to the antifungal and antiaflatoxigenic activities of MEO. Interestingly, these two materials increased AFB production in A. flavus by upregulating the expression of most genes related to AFB biosynthesis by 3- to 60-fold. Overall, MEO and C10 could be suitable candidates as natural preservatives to control fungal infection and mycotoxin contamination in foods and feeds as Generally Recognized As Safe (GRAS) in the Flavor and Extract Manufacturers Association of the United States (FEMA), and MEO is a more suitable substance than C10 because of its wider range of uses and higher allowed concentration than C10.

The study of fungal contamination in food and mycotoxicoses is a priority today, both internationally and nationally. The purpose of this study is to have a general view over the quality of the most common spices that are sold in Romanian markets, by assessing the degree of fungal, bacterial and mycotoxin contamination in pepper and chili powders. We tested four types of spices: white pepper, black pepper, sweet and hot chili powders from 12 different distributing companies, summing a total of 35 sample types. The fungal and bacterial load was assessed by Standard Plate Count, while the mycotoxin content by High-performance liquid chromatography. Environmental conditions (humidity, pH) and the selling price for each product were also followed. Fungi were observed in 72.7% of black pepper samples, 33.3% in white pepper, 30% in sweet chili and 25% in hot chili products. The most common isolated fungus was Aspergillus spp., while Rhizopus, Mucor, Fusarium, Penicillium, Absidia species were found, in smaller percentage. Four producers (44.4%) presented fungal contamination of over 10^3 CFU/g and two producers (22.2%) presented no fungal contamination in their products. Bacterial contamination was found in 85.7% of the tested products, consisting mostly in Bacillus spp. Aflatoxin B1 was present in all the tested products, mostly in black pepper (mean value 126.3 ng/g); Ochratoxin A was present in sweet chili (mean value 328 ng/g) and Zearalenone in hot chili (mean value 604 ng/g) and sweet chili (mean value 382 ng/g). All spices presented either fungal contamination, mycotoxin contamination, or both. The high humidity and the high pH of spices represent favorable conditions for fungal growth. The selling price was partly related to the physic-chemical conditions and microbiological quality of the spices.