Determination of Mycobiota and Microbial Loads of Grapes Grown in Bozcaada, Turkey

Abstract

Bozcaada which is a province of Çanakkale, Turkey, is located between the 390 48 north parallel and 260 east meridians. The largest livelihood of Bozcaada is viticulture. Therefore, in our study, microbial load, and mould diversity of the Çavuş (table) and Karalahna (wine) grapes which are endemic to the island were evaluated, and ochratoxin production potentials of Aspergillus isolates were investigated by HPLC. A total of 6 vineyards with Çavuş and Karalahna grapes were sampled in 2015 and 2016. Total aerobic mesophilic bacteria count of grapes ranged between 0.00 and 4.21 log CFU/g, yeast load between 0.00 and 2.66 log CFU/g and mould load between 1.67 and 3.20 log CFU/g. A total of 2264 mould isolates were taken from samples. All isolates were identified at the genus level. Aspergillus spp. and Penicillium spp. were the most isolated species in 2015, while Alternaria spp. and Cladosporium spp. were the most isolated species in 2016. It was determined that 13.78% (312) of the isolates were Aspergillus spp., 54 of these isolates, have been selected and identified at the species level. Twenty-one of the black Aspergillus isolates were identified as A. niger / A. acidus, twenty-four of them were A. carbonarius and one of them is A. ibericus. The two white isolates were found to be A. candidus, the creamy brownish-spore forming isolate was A. terreus, and three green isolates were identified as A. flavus, A. calidoustus and A. sydowii. Six isolates (4 A. niger, 1 A. calidoustus, and 1 A. sydowii) were producing OTA. The amounts of ochratoxins varied from 0.80 to 74.01 ng/g.

In vitro Antifungal Activity of Mentha piperita and Thymus vulgaris Essential Oils against Ochratoxigenic Aspergillus carbonarius Isolated from Bozcaada Çavuş Grape

“…A. carbonarius PP264185 (NCBI gen bank number) (closely related species accession number MK778845.1), isolated from grape samples taken from the Çavuş vineyard in Bozcaada Çayır location in 2015, was used in the study (Özcan Ateş and Zorba, 2020;Özcan Ateş et al, 2024). It was determined through HPLC analysis that the isolate produced 49.448 ± 0.354 ppm of OTA in the medium (Özcan Ateş et al, 2024).…”

“…On the other hand, A. niger and A. carbonarius also produce OTA in grapes, raisins, and wine (Chiotta et al, 2013;Hua et al, 2014;Pantelides et al, 2017). A. carbonarius is the primary ochratoxigenic fungus found on grapes, especially in Mediterranean countries, and contaminates grapes during ripening (Pantelides et al, 2017;Dammak et al, 2018;Özcan Ateş and Zorba, 2020).…”