AUTHOR=Kanpiengjai Apinun , Kodchasee Pratthana , Unban Kridsada , Kumla Jaturong , Lumyong Saisamorn , Khunnamwong Pannida , Sarkar Dipayan , Shetty Kalidas , Khanongnuch Chartchai 

TITLE=Three new yeast species from flowers of Camellia sinensis var. assamica collected in Northern Thailand and their tannin tolerance characterization

JOURNAL=Frontiers in Microbiology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1043430

DOI=10.3389/fmicb.2023.1043430

ISSN=1664-302X

ABSTRACT=<p>Our recent research study focused on Miang fermentation revealed that tannin-tolerant yeasts and bacteria play vital roles in the Miang production process. A high proportion of yeast species are associated with plants, insects, or both, and nectar is one of the unexplored sources of yeast biodiversity. Therefore, this study aimed to isolate and identify yeasts of tea flowers of <italic>Camellia sinensis</italic> var. <italic>assamica</italic> and to investigate their tannin tolerance, which is a property essential to Miang production processes. A total of 82 yeasts were recovered from a total of 53 flower samples in Northern Thailand. It was found that two and eight yeast strains were distinct from all other known species within the genera <italic>Metschnikowia</italic> and <italic>Wickerhamiella</italic>, respectively. These yeast strains were described as three new species, namely, <italic>Metschnikowia lannaensis</italic>, <italic>Wickerhamiella camelliae</italic>, and <italic>W. thailandensis</italic>. The identification of these species was based on phenotypic (morphological, biochemical, and physiological characteristics) and phylogenetic analyses of a combination of the internal transcribed spacer (ITS) regions and the D1/D2 domains of the large subunit (LSU) ribosomal RNA gene. The yeast diversity in tea flowers acquired from Chiang Mai, Lampang, and Nan provinces had a positive correlation with those acquired from Phayao, Chiang Rai, and Phrae, respectively. <italic>Wickerhamiella azyma</italic>, <italic>Candida leandrae</italic>, and <italic>W. thailandensis</italic> were the species uniquely found in tea flowers collected from Nan and Phrae, Chiang Mai, and Lampang provinces, respectively. Some of the tannin-tolerant and/or tannase-producing yeasts were associated with yeasts in the commercial Miang process and those found during Miang production, i.e., <italic>C. tropicalis</italic>, <italic>Hyphopichia burtonii</italic>, <italic>Meyerozyma caribbica</italic>, <italic>Pichia manshurica</italic>, <italic>C. orthopsilosis</italic>, <italic>Cyberlindnera fabianii</italic>, <italic>Hanseniaspora uvarum</italic>, and <italic>Wickerhamomyces anomalus</italic>. In conclusion, these studies suggest that floral nectar could support the formation of yeast communities that are beneficial for Miang production.</p>