Biodiversity of epiphytic yeasts on post-harvest table grapes in markets of Tabriz, Iran

Several reports are available on species diversity of yeasts on grape berries in different grapevine producing countries, including Iran. However, there is a paucity of knowledge on species diversity of yeasts on post-harvest table grapes worldwide. Hence, this study was performed to explore the species diversity of epiphytic yeasts on post-harvest table grapes in markets of Tabriz, northwest Iran. Towards this aim, 120 grape samples, mostly Keshmesh, Shahani, Gezeluzum and Shast-arous cultivars, were purchased from selected main markets in Tabriz and subjected to yeast isolation. Total number of 180 epiphytic yeast isolates were recovered. The isolates were preliminary grouped based on the morphological characteristics and DNA fingerprinting profiles using MSP-PCR fingerprinting technique. The D1/D2 domain of the 26S rDNA was amplified and sequenced for one or two isolates representing each fingerprinting group. Totally, 20 isolates were sequenced and the phylogeny inferred from sequence data of D1/D2 region revealed a rich diversity of yeast species on post-harvest table grape berries. Sixteen yeast species belonging to both ascomycetes and basidiomycetes were identified. The majority of identified yeast species (75%) belonged to ascomycetes. Aureobasidium pullulans, Hanseniaspora uvarum and Metschnikowia sinensis are reported as the most frequently isolated yeasts. In this study, Clavispora lusitaniae and Cyberlindnera fabianii are newly reported on grape berries worldwide and C. lusitaniae, C. fabianii, Wickerhamomyces anomalus and Yamadazyma mexicana represent new records for the mycobiota of Iran.