Biodiversity of ochratoxigenic Aspergillus species isolated from çavuş and karalahna grapes in Bozcaada, Türkiye

Abstract

This study reported the presence and OTA production of ochratoxigenic Aspergillus species isolated from Bozcaada Çavuş and Karalahna grapes. The study was conducted with Aspergillus isolates isolated from grape samples collected during ripening in 2015 and 2016. Thin-layer chromatography was used to determine the secondary metabolite profiles of 290 Aspergillus isolates. Out of these, 122 isolates were found to be possible OTA producers. 43 isolates, selected based on their colony morphology of 122 isolates in different culture media, were identified using calmodulin gene sequencing analysis. The identified isolates were determined to be A. tubingensis, A. carbonarius, A. niger/welwitschia/awamori, A. welwitschia, A. spelaeus, and A. fructus. OTA production was investigated in six isolates. Using HPLC-FLD, these isolates were found to produce OTA in quantities ranging from 3.550 ± 0.240 to 92.346 ± 0.818 ppb. Consequently, OTA-producing Aspergillus species were isolated from grapes. The presence of A. spelaeus and A. fructus was reported for the first time in grapes. A. fructus has been found to be a new record for Türkiye.