茶菌人工复合菌剂构建和发酵性能分析

Construction of a Synthetic Microbial Community for Kombucha Fermentation and Analysis of Its Fermentation Characteristics

利用从茶菌中分离纯化的4个优势菌株构建人工复合菌剂。通过单独培养和不同复合方式培养的比较,确定菌株在茶菌发酵和菌膜形成中的作用;采用高效液相色谱、顶空固相微萃取和气相色谱-质谱联用等方法分析茶菌发酵过程中主要生化成分变化;经历多次传代接种后,采用人工分离和宏基因组分析相结合分析菌群组成和稳定性。结果表明:供试的4个菌株中,葡糖醋杆菌J5(Gluconacetobacter sp.J5)是产生纤维素和菌膜的核心菌株。混合菌株组合C3C5C6J5发酵后在菌体生长、糖利用、发酵液pH值、总酸度和茶多酚含量等指标与自然发酵相似。经历6代转接后菌群稳定,复配的菌株在人工菌群中均为优势菌株。表明从天然茶菌饮料中分离纯化功能菌株,通过菌株复配构建稳定的人工发酵剂可行,为茶菌的标准化工业生产打下基础。

An artificial microbial consortium was constructed by using four dominant strains isolated from tea fungus.Through comparison of single and mixed cultures,we determined the role of these strains in the fermentation of tea fungus and the formation of biofilm.High performance liquid chromatography(HPLC)and headspace solid-phase microextraction(HS-SPME)coupled to gas chromatography-mass spectrometry(GC-MS)were used to analyze the major biochemical components in the fermentation process of tea fungus.After multiple passages,the stability of the microbial consortium was analyzed using a combination of isolation and metagenomic analysis.The results showed that among the four strains tested,Gluconacetobacter sp.J5 was the core strain producing cellulose and biofilm.The fermentation characteristics of the synthetic microbial consortium was comparable to natural fermentation in terms of cell growth,sugar utilization,pH,total acidity and tea polyphenol content.The microbial consortium was stable and all four strains were dominant in the microbial consortium after six passages.These results suggest that the functional strains isolated from tea fungus can be used to construct a stable artificial starter culture,which will lay the foundation for the standardized industrial production of tea fungus.