文献类型： 外文期刊

作者： Zou, Yao ¹ ; Zhang, Ying ¹ ; Tian, Yun ¹ ; Liu, Minqiang ¹ ; Yuan, Yue ¹ ; Lai, Yuqing ¹ ; Liu, Xuyi ¹ ; Xu, Wei ¹ ; Tan, Liqiang ¹ ; Tang, Qian ¹ ; Li, Pinwu ¹ ; Xu, Jingyi ¹ ;

作者机构： 1.Sichuan Agr Univ, Coll Hort, Dept Tea Sci, Chengdu, Peoples R China

2.Tea Refining & Innovat Key Lab Sichuan Prov, Chengdu, Peoples R China

3.Chongqing Acad Agr Sci, Tea Res Inst, Chongqing, Peoples R China

关键词： microbial community; Sichuan South-road Dark Tea; organoleptic quality; Aspergillus niger; pile-fermentation

期刊名称：FRONTIERS IN MICROBIOLOGY （ 影响因子：6.064； 五年影响因子：6.843 ）

ISSN：

年卷期： 2022 年 13 卷

页码：

收录情况： SCI

摘要： Microbes are critical in the Sichuan South-road Dark Tea (SSDT) organoleptic quality development during pile-fermentation. Piled tea center at fermenting metaphase is crucial for the conversion of its quality components. In this study, we investigated the microbial community of piled SSDT center below the stacked tea surface of 15 cm (SSDTB), 50 cm (SSDTX), and 85 cm (SSDTH) on the second turning time of pile-fermentation, respectively. Results showed that SSDTH and SSDTB had a higher similarity in the microbial community. Pantoea (36.8%), Klebsiella (67.7%), and Aspergillus (35.3%) were the most abundant in SSDTH, SSDTB, and SSDTX, respectively. We found 895 species were common among all samples, but 86, 293, and 36 species were unique to SSDTB, SSDTX, and SSDTH, respectively. Aspergillus niger showed high co-occurrence and was positively correlated with numerous microbes in SSDT samples, and Aspergillus niger M10 isolated from SSDTX was excellent at enhancing soluble sugar (SS), amino acids (AAs), theaflavin (TF), and thearubigins (TR) contents, while decreasing catechin (Cat), tea polyphenols (TPs)/AA, Caf/SS, Cat/SS, TPs/SS, and (TPs + Caf)/SS levels in AM10 post-fermentation, as compared with the control. Moreover, it also produced a noticeable difference in the CIELab parameters in dried, liquor, and infused tea colors between AM10 and control during fermentation. When it was further inoculated on differential mediums, we detected glycoside hydrolases, namely, beta-glucosidase, mannosidase, pectinase, cellulase, amylase, and alpha-galactosidase being secreted by Aspergillus niger M10. Taken together, SSDXT presented a more unique microbial community. Aspergillus niger M10 probably improved the sweet and mellow taste, and the yellow brightness and red color of SSDT during fermentation. It also provided new insights into the microbial profile and organoleptic quality development mechanism of SSDT during pile-fermentation.