Yeast species associated with spontaneous fermentation of taberna, a traditional palm wine from the southeast of Mexico

The aim of this study was to isolate and identify the yeasts present in taberna, a traditional palm wine from Mexico, which is produced by natural fermentation of the palm sap obtained from Acrocomia aculeata. A total of 450 yeast isolates were obtained from 45 taberna samples collected over 15 days of tapping at the end of fed-batch fermentation (12 hours of feeding and fermentation of the sap in the canoe) from three coyol palm trees. The yeast isolates were identified using restriction pattern analysis of the internal transcribed spacer region 5.8S-ITS and by sequence analysis of the D1/D2 divergent domain of the 26S rRNA gene. Nine different yeast species were identified in the taberna samples tested, namely, Saccharomyces cerevisiae, Hanseniaspora guilliermondii, Candida tropicalis, Candida intermedia, Kazachstania unispora, Kazachstania exigua, Meyerozyma guilliermondii, Pichia kudriavzevii (Issatchenkia orientalis) and Pichia kluyveri. The non-Saccharomyces yeasts H. guilliermondii and C. tropicalis were detected in samples from all three palm trees, while S. cerevisiae was detected in samples from only two of the palm trees. The frequency and distribution of the yeast species were different in the samples of each palm tree, which indicated that the inoculum in the palm sap may be deposited randomly by different vectors. This study is the first to characterize the yeast population associated with the palm wine named taberna.