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ORIGINAL RESEARCH article

Front. Microbiol.
Sec. Food Microbiology
Volume 15 - 2024 | doi: 10.3389/fmicb.2024.1408645
This article is part of the Research Topic Microorganisms in Tea and Tea Beverages View all articles

The carbohydrate metabolism and expression of carbohydrate-active enzyme genes in Aspergillus luchuensis fermentation of tea leaves

Provisionally accepted
Ruoyu Li Ruoyu Li *Teng Wang Teng Wang Nianguo Bo Nianguo Bo Qi Wang Qi Wang Qiuyue Chen Qiuyue Chen Liang Zhengwei Liang Zhengwei Yanhui Guan Yanhui Guan Bin Jiang Bin Jiang Yan Ma Yan Ma Ming Zhao Ming Zhao
  • Yunnan Agricultural University, Kunming, China

The final, formatted version of the article will be published soon.

    Carbohydrates that make up 20% to 25% of tea beverages are responsible for their flavor and bioactivity. Pu-erh tea's carbohydrates change during microbial fermentation and require further research. In this study, we examined the carbohydrate metabolism and expression of carbohydrate-active enzyme genes during the fermentation of tea leaves with Aspergillus luchuensis. Widely targeted metabolomics analysis, high performance anion exchange chromatography measurements and transcriptomics were used in this study. After fermentation, the levels of soluble sugar, hemicellulose, lignin, eight monosaccharides, and seven sugar alcohols increased. Meanwhile, the relative contents of polysaccharides, D-sorbitol, D-glucose, and cellulose decreased. High expression of 40 genes encoding 16 carbohydrate enzymes was observed during fermentation (FPKM>10). These genes encode L-iditol 2-dehydrogenase, pectinesterase, polygalacturonase, α-amylase, glucoamylase, endoglucanase, β-glucosidase, β-galactosidase, α-galactosidase, α-glucosidase, and glucose-6-phosphate isomerase, among others. These enzymes are known to break down polysaccharides and cell wall cellulose, increasing the content of monosaccharides and soluble sugar.

    Keywords: Aspergillus luchuensis, fermentation tea, carbohydrate, Glycosides, CAZymes

    Received: 28 Mar 2024; Accepted: 09 May 2024.

    Copyright: © 2024 Li, Wang, Bo, Wang, Chen, Zhengwei, Guan, Jiang, Ma and Zhao. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Ruoyu Li, Yunnan Agricultural University, Kunming, China

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.