Genomic diversity in ochratoxigenic and non ochratoxigenic strains of Aspergillus carbonarius

Abstract

Ochratoxin A (OTA) is a mycotoxin with nephrotoxic effects on animals and humans. Aspergillus carbonarius is the main responsible for OTA contamination of grapes and derived products. We present the genome resequencing of four A. carbonarius strains, one OTA producer and three atypical and unique non-OTA producing strains. These strains were sequenced using Illumina technology and compared with a reference genome of this species. We performed some specific bioinformatics analyses in genes involved in OTA biosynthesis. Data obtained in this study revealed the high genomic diversity within A. carbonarius strains. Although some gaps of more than 1,000 bp were identified in non-ochratoxigenic strains, no large deletions in functional genes related with OTA production were found. Moreover, the expression of five genes of the putative OTA biosynthetic cluster was down regulated under OTA-inducing conditions in the non-ochratoxigenic strains. Knowledge of the regulatory mechanisms involved in OTA biosynthesis will provide a deeper understanding of these non-ochratoxigenic strains.