Diversity and molecular determination of wild yeasts in a central Washington State vineyard

Abstract

Yeasts were isolated from grapes collected from a research vineyard at the WSU-IAREC, located at Prosser, WA. Species determination was based on cultural features, microscopic morphology, physiological tests and analysis of ITS and D1/D2 rDNA sequence data. Fifty-three species were found distributed among five fungal subphyla, a greater number than expected based on similar published studies. Within Saccharomycotina, 13 species in the genera Candida, Hanseniaspora, Metschnikowia, Meyerozyma, Pichia, Wickerhamomyces and Yamadazyma were determined. Isolates within the Metschnikowia pulcherrima clade appeared to possess considerable diversity. Pucciniomycotina was represented by 12 species, in Curvibasidium, Rhodosporidium, Rhodotorula, Sporidiobolus and Sporobolomyces. Five phylogenetically distinct species in the subphylum could not be assigned to any described species. Isolates in Ustilaginomycotina were placed in Pseudozyma except for a single strain determined to be Rhodotorula bacarum. Within Agaricomycotina, 17 species in the genera Cryptococcus, Cystofilobasidium, Hannaella, Holtermanniella and Mrakiella were determined. Seven species of yeastlike Pezizomycotina were found, representing classes Leotiomycetes, Dothideomycetes and Sordariomycetes. Isolates of Aureobasidium pullulans represented three phylogenetically distinct subspecific lineages. Seventeen species identified in this study were previously unreported from wine grapes and 18 species were unreported from North America. Several strains appear to represent undescribed species, including the recently described Curvibasidium rogersii.

Efficacy of Dimethyl Dicarbonate Against Yeasts Associated with Washington State Grapes and Wines

“…Of the total 55 species of yeasts characterized, however, 16 were not previously reported to be found on wine grapes and 17 were not previously isolated within North America (Bourret et al . , ).…”

“…Recently, Bourret et al . () isolated a number of yeasts from Chardonnay and Riesling vineyards located in central Washington State including Hanseniaspora uvarum , Metschnikowia pulcherrima and Pichia membranifaciens , all species known to occur on grapes and/or to be present in wines (Barata et al . ).…”

“…Given the diversity of yeasts isolated by Bourret et al . (), it seems likely that at least some could have a wide range effects on wine quality.…”

Yeast diversity on grapes in two German wine growing regions

“…The species was found on grapes in North America before (Bourret et al, 2013). To our knowledge ours is the first description of Cu.…”

Pattersoniomyces tillandsiae gen. et comb. nov.: linking sexual and asexual morphs of the only known smut fungus associated with Bromeliaceae

“…Ustilaginomycotinous yeasts are commonly detected from very diverse habitats, using both culture dependent and culture-independent methods (e.g., Boekhout et al 2003;Inácio et al 2008;Sipiczki and Kajdacsi 2009;Bourret et al 2013;Nasr et al 2014;Nasanit et al 2015Nasanit et al , 2016Tantirungkij et al 2015;Wang et al 2015;Kijpornyongpan and Aime 2017;Kruse et al 2017). The links between asexual and sexual morphs were demonstrated only for a few species, for example between Pseudozyma prolifica Bandoni and Mycosarcoma maydis (DC.)…”