Yeast diversity in traditional fermented foods of ethnic minorities in China, with the descriptions of four new yeast species

Fermented foods have been produced by humans since prehistoric times and are consumed worldwide today due to their enhanced nutritional value, taste and flavor, and benefits for human health. Various microorganisms are essential agents responsible for food fermentation and have been extensively studied using both culture-dependent and - independent methods. However, previous research has mainly focused on fermented foods produced on a large scale in urbanized areas.

In this study, we collected 255 samples of diverse traditional fermented foods — including alcoholic beverages, amylolytic starters, fruit vinegar, and fermented products of milk, vegetables, cereals, legumes, fish, meat, and other materials — from ethnic minority areas of China through a citizen science initiative for the study of yeast diversity. A total of 516 yeast strains were isolated, and 81 yeast species, including four new species, were identified based on sequence analyses of the D 1 / D 2 domain of the large subunit rRNA gene and the internal transcribed spacer region.

The proposals of the new species were further supported by whole-genome average nucleotide identity (ANI) analysis. The dominant species isolated were Saccharomyces cerevisiae, Pichia kudriavzevii, Wickerhamomyces anomalus, Saccharomycopsis fibuligera, and Clavispora lusitaniae. The new species are described as Blastobotrys guizhouensis sp. nov., Wickerhamiella shiruii sp. nov., Trichosporon jiuqu sp. nov., and Parajaminaea alba sp. nov.

This study demonstrates the high yeast diversity in traditional fermented foods of ethnic minorities in China. These yeast resources are of special value for both basic and applied research in the future.