茶窖中微生物群落分布多样性及普洱茶内生菌和茶品质的研究

Microbial Community Diversity,and Endophytes and Quality of Pu'er Tea in Tea Cellar

为了探究茶窖中微生物群落结构的多样性,建立普洱茶茶窖微生物库,明确普洱生茶由于不同的存放环境而造成的茶品质差异的原因,采用平板涂布分离技术和测序技术,对从茶窖环境中分离的微生物和茶叶内生菌进行了培养和分子鉴定,并通过感官测评和成分检测对茶品质进行了判定。结果显示,在茶窖环境中经分离纯化共得到157株细菌、119株真菌和163株茶叶内生菌。茶窖中长期累积的菌斑鉴定结果显示,大部分为曲霉属,数量最多的是黑曲霉。普洱茶的重金属、农残、致病菌、水分、总灰分和水浸出物均符合国家标准,存放两年后,相比于自然环境存放的普洱茶,窖藏的普洱茶的茶多糖、茶褐素和咖啡碱含量增高,而游离氨基酸、茶氨酸、茶多酚、儿茶素和茶红素的含量降低。研究表明曲霉属,尤其是黑曲霉,可能对普洱茶品质的转化影响很大。本研究可以为普洱茶窖藏技术的推广提供一定的理论基础。

An exploration is made into the microbial community structure and diversity in Pu'er tea cellar in a view to establishing a microbial bank of Pu'er tea in the tea cellars and clarifying the difference in tea quality caused by different storage environments for Pu'er raw tea.The microorganisms isolated from the tea cellar and endophytes isolated from Pu'er teas were cultured and identified by plate coating and sequencing,respectively.A sensory evaluation and composition detection of Pu'er teas was carried out.The results showed that there were a total of 157 strains of bacteria and 119 strains of fungi isolated and purified from the tea cellar,and 163 strains of endophytes isolated and purified from the Pu'er teas.Identification of the plaques accumulated for a long term in the tea cellar showed that most of the microorganisms in the microbial plaques in the tea cellar were fungi of Aspergillus species with Aspergillus niger being the highest in number.The heavy metals,agricultural residues,pathogens,moisture content,total ash content and water extract of Pu'er teas all met the national standards.After two years of storage,Pu'er teas stored in the tea cellar were higher in the contents of tea polysaccharide,theabrownin and theobromine and lower in the contents of free amino acid,theanine,tea polyphenol,catechin and thearubigins than the naturally stored Pu'er tea.This indicates that Aspergillus,especially Aspergillus niger,maybe has a great influence on the quality of Pu'er tea.This study provides reference for the popularization of Pu'er tea cellar technology.