Isolation and Identification of Fusarium Species from Maize and Wheat and Assessment of Their Ability to Produce Fumonisin B۱

Objective: Fusarium species are prevalent contaminants of foodstuffs and agricultural crops.  They produce fumonisins, which are carcinogenic mycotoxins. The present study has evaluated maize and wheat samples from ten provinces in Iran that were contaminated with Fusarium species. Special attention was paid to the ability of the isolates to produce fumonisin B۱ (FB۱) as a public health hazard. Methods: We collected ۳۲ maize and ۱۵ wheat samples from ten provinces that were major cultivation areas. Samples surface disinfected with a ۱% sodium hypochlorite solution for ۲ minutes. Fusarium species were isolated by the flotation method on malachite green agar. Pure cultures on potato dextrose agar (PDA) were identified using a combination of macroscopic and microscopic morphological criteria. The ability of the isolates to produce FB۱ was evaluated by thin layer chromatography (TLC) and the amounts of fumonisin B۱ produced were assessed by high performance liquid chromatography (HPLC). Results: A total of ۵۵ Fusarium isolates that belonged to five species were isolated. There were ۲۷ of the ۳۲ maize samples (۸۴.۴%) and ۱۱ of ۱۵ wheat samples (۷۳.۳%) that were contaminated with Fusarium species. Species consisted of F. verticillioides (۲۳ isolates), F. proliferatum (۲۲ isolates), F. subglutinans (۵ isolates), F. nygamai (۴ isolates) and F. redolens (۱ isolate) based on morphological criteria. Twenty-two of the ۵۵ (۴۰%) Fusarium isolates produced FB۱ in a total range from ۲۳۰.۴ to ۹۵۶۵ µg/ml. The highest amounts of FB۱ production were related to toxigenic isolates of F. verticillioides and F. proliferatum. Conclusion: Results of the present work indicates a high degree of contamination of maize and wheat with Fusarium strains that belong to the Gibberella fujikuroi species complex وparticularly F. verticillioides and F. proliferatum. This contamination is a potential public health threat due to food spoilage and subsequent production of high levels of carcinogenic FB۱.

کلیدواژه ها:

Wheat ، maize ، Fusarium species ، Fumonisin B۱ ، Food contamination ، گونههای فوزاریوم ، فومونیسین B۱ ، آلودگی مواد غذایی ، ذرت ، گندم