Molecular profile of non‑afatoxigenic phenotype in native strains of Aspergillus favus.

Raksha Rao, K. and Vipin, A. V. and Venkateswaran, G. (2020) Molecular profile of non‑afatoxigenic phenotype in native strains of Aspergillus favus. Archives of Microbiology, 202. pp. 1143-1155.

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Abstract

Afatoxins are the most common mycotoxin contaminant reported in food and feed. Afatoxin B1, the most toxic among diferent afatoxins, is known to cause hepatocellular carcinoma in animals. Aspergillus favus and A. parasiticus are the main producers of afatoxins and are widely distributed in tropical countries. Even though several robust strategies have been in use to control afatoxin contamination, the control at the pre-harvest level is primitive and incompetent. Therefore, the aim of the study was to isolate and identify the non-afatoxigenic A. favus and to delineate the molecular mechanism for the loss of afatoxin production by the non-afatoxigenic isolates. Eighteen non-afatoxigenic strains were isolated from various biological sources using cultural and analytical methods. Among the 18 isolates, 8 isolates produced sclerotia and 17 isolates had type I deletion in norB-cypA region. The isolates were confrmed as A. favus using gene-specifc PCR and sequencing of the ITS region. Later, afatoxin gene-specifc PCR revealed that the defect in one or more genes has led to nonafatoxigenic phenotype. The strain R9 had maximum defect, and genes avnA and verB had the highest frequency of defect among the non-afatoxigenic strains. Further, qRT-PCR confrmed that the non-afatoxigenic strains had high frequency of defect or downregulation in the late pathway genes compared to early pathway genes. Thus, these non-afatoxigenic strains can be the potential candidates for an efective and profcient strategy for the control of pre-harvest afatoxin contamination.

Item Type:	Article
Uncontrolled Keywords:	Afatoxin · Aspergillus favus · Non-afatoxigenic · Afatoxin biosynthesis pathway
Subjects:	500 Natural Sciences and Mathematics > 07 Life Sciences > 03 Biochemistry & Molecular Biology 500 Natural Sciences and Mathematics > 07 Life Sciences > 04 Microbiology > 04 Fungi
Divisions:	Fermentation Technology and Bioengineering
Depositing User:	Food Sci. & Technol. Information Services
Date Deposited:	30 Sep 2020 09:31
Last Modified:	21 Dec 2020 08:18
URI:	http://ir.cftri.res.in/id/eprint/14467

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