Mycotoxins are secondary metabolites of some fungal species and represent important contaminants of food and feed. This study aimed to explore the biological control activity of Bacillus megaterium BM344-1 volatile organic compounds (VOCs) on the growth and mycotoxin production of single representatives of the toxigenic species Aspergillus flavus , Aspergillus carbonarius , Penicillium verrucosum , and Fusarium verticillioides . In vitro co-incubation experiments indicated the P. verrucosum isolate as the most sensitive one, with a growth inhibition ratio of 66.7%, followed by A. flavus (29.4%) and F. verticillioides (18.2%). Exposure of A. flavus , P. verrucosum, and F. verticillioides to BM344-1 VOCs resulted in complete inhibition of aflatoxins (AFB 1 , AFG 1 , and AFG 2 ), ochratoxin A, and fumonisin B 1 (FB 1 ) synthesis on artificial media, respectively. In vivo experiments on maize kernels showed 51% inhibition of fungal growth on ears simultaneously infected with A. flavus spores and exposed to BM344-1 volatiles. Likewise, AF synthesis by A. flavus was significantly ( p < 0.05) inhibited (25.34 ± 6.72 μg/kg) by bacterial volatiles as compared to that in control maize ears (91.81 ± 29.10 μg/kg). Gas chromatography–tandem mass spectrometry-based analysis of headspace volatiles revealed hexadecanoic acid methyl ester (palmitic acid) and tetracosane as bioactive compounds in the BM344-1 volatilome. Bacterial volatiles have promising potential to control the growth and mycotoxin synthesis of toxigenic fungi and may present valuable aid in the efforts to warrant food and feed safety.

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Cassava (Manihot esculenta ) is a major staple food crop across tropical sub-Saharan Africa. Poor drying during processing or storage, especially during the rainy season, often results in contamination by fungi such as Aspergillus, Fusarium and Penicillium. Aflatoxins are among the mycotoxins which are secondary metabolites produced by some strains of Aspergillus flavus and Aspergillus parasiticus which are a major health concern to man and livestock because of their acute and chronic health effects. The aim of this study was to determine aflatoxin contamination and to quantify the aflatoxin levels in cassava flour. A total of 36 samples of Cassava flour were collected in three (3) major markets in Zaria, these are: Samaru, Sabon Gari and Zaria City Markets to determine and quantify aflatoxins using enzyme linked immunosorbent Assay (ELISA). The results obtained showed that 22 out of 36 were contaminated with total aflatoxins at the range of 2.0µg/kg to 7.5µg/kg. This study indicated that there is low aflatoxin concentration in the Cassava and suggested that the cassava flour is safe and good for human consumption.