高通量测序研究霉变黑毛茶的真菌多样性

摘要

为了解高湿条件下霉变黑毛茶的微生物情况,通过人工促霉培养和Illumina Miseq高通量测序技术研究了黑毛茶霉变过程的真菌多样性,并探讨了不同OTU(Operational Taxonomic Unit)阈值划分对真菌多样性生物信息学分析的影响.结果表明,高湿条件下霉变黑毛茶的真菌分类学地位集中于2门(Ascomycot,Basidiomycota)6属(Aspergillus,Galactomyces,Ogataea,Debaryomyces,Pichia和Cryptococcus),其中曲霉属(Aspergillus)真菌相对丰度值最大,达98%以上.不同OTU阈值划分水平导致了同一样本的分类学地位、多样性指数及群落结构组成的分析结果存在差异.相似性0.97水平下的OTU聚类真菌群落Shannon多样性指数为0.15~0.43,0.99水平下Shannon多样性指数为0.28~0.58.曲霉属(Aspergillus)真菌为高湿条件下导致仓储黑毛茶霉变的优势真菌种群.%In order to understand the feature of microbe in the mildew dark tea under high humidity conditions, Illumina Miseq high-throughput sequencing was performed to study fungi diversity by artificial culture of certain fungi. The influence of the OTU (Operational Taxonomic Unit) threshold on the bioinformatic analysis results of fungal diversity was also discussed. The results showed that the mildew dark tea fungus under high humidity conditions were mainly classified into 2 phylum (Ascomycota, Basidiomycota) and 6 genera (Aspergillus, Galactomyces, Ogataea, Debaryomyces, Pichia and Cryptococcus), with the highest abundance value of Aspergillus (>98%). The different OTU thresholds resulted in the difference in the taxonomic status, diversity index and community structure in the same sample. The Shannon diversity index of OTU under the 0.97 was 0.15-0.43, and the Shannon diversity index under 0.99 was 0.28-0.58. Under high moisture conditions aspergillus was the major fungi causing dark tea mildew in storage.