Survey and toxigenic abilities of Aspergillus, Fusarium, and Alternaria fungi from wheat and paddy grains in Shanghai, China

Abstract

A systematic study was carried out on 638 wheat and paddy grains (including fresh and stored samples) collected in 2021 from Shanghai, China, to identify the major mycobiota and their toxigenic abilities. A total of 349 fungi, namely, 252 Fusarium, 53 Aspergillus, and 44 Alternaria, were characterized by morphological and molecular identification. Fusarium and Aspergillus were more frequently isolated in paddy with Fusarium sambucinum species complex and Aspergillus section flavi as the predominant species, respectively. The genus Alternaria was the most frequently isolated fungal species in wheat. The toxin-producing potentials of the identified fungi were further evaluated in vitro. Deoxynevalenol (DON) was produced by 34.5% of Fusarium isolates and zearalenone (ZEN) was produced by 47.6% of them, and one isolate also processed the abilities for fumonisin B1 (FB1), B2 (FB2), and B3 (FB3) productions. Aflatoxin B1 (AFB1), B2 (AFB2), and G1 (AFG1) were only generated by Aspergillus section flavi, with the production rate of 65.5%, 27.6%, and 13.8%, respectively. Alternariol (AOH) was the most prevalent Alternaria toxin, which could be produced by 95.5% of the isolates, followed by alternariol monomethyl ether (AME) (72.7%), altenuene (ALT) (52.3%), tenuazonic acid (TeA) (45.5%), tentoxin (TEN) (29.5%), and altenusin (ALS) (4.5%). A combinational analysis of mycobiota and toxigenic ability allowed us to provide comprehensive information about the production mechanisms of mycotoxins in wheat and paddy in a specific geographic area, and will be helpful for developing efficient prevention and control programs.

Potential fungicidal and antiaflatoxigenic effects of cinnamon essential oils on Aspergillus flavus inhabiting the stored wheat grains

“…The fungal genera were identified according to their microscopical and macroscopical features of the universally keys [32][33][34][35]. The potent isolates were molecularly identified based on the sequence of their internal transcribed spacers (ITS) using genomic DNA as template for PCR [36][37][38], with primers ITS4 5′-GGA AGT AAA AGT CGT AAC AAGG-3′ and ITS5 5′-TCC TCC G CTT ATT GAT ATG C-3′. The reaction of PCR contains 10 μl of 2 × PCR master mixture (Cat.…”

Research on Pathogenic Fungi and Mycotoxins in China (Volume II)

“…The presence of pathogenic fungi and contamination of mycotoxins in food and feed pose significant threats and challenging issues to food in the world. Pathogenic fungal species, such as Aspergillus , Penicillium , Fusarium , and Alternaria , are major concerns in the food and feed industry due to their synthesis of mycotoxins, which are leading to significant economic losses in China [ 1 , 2 , 3 ]. Mycotoxins, which are naturally produced by certain fungi, can contaminate various crops as well as food and feed products under the specific conditions that occur during the phases of harvesting, post-harvest, and processing [ 4 , 5 ].…”