双孢蘑菇栽培基质二次发酵过程真菌群落结构变化分析

Change Analysis of Fungal Community Structure During the Secondary Fermentation Process of Agaricus bisporus Cultivation Substrate

为明确双孢蘑菇栽培基质二次发酵过程中微生物动态和多样性,采用高通量测序技术,测定了双孢蘑菇栽培基质的二次发酵过程中真菌群落结构变化,并探究群落组成与环境因子的关系。结果表明:双孢蘑菇栽培基质二次发酵过程4个发酵阶段真菌分类单元(OTU)总数999个,包含10个门、26个纲、56个目、126个科、240个属和403个种,其中嗜热链球菌属(12.72%~42.63%)、unclassified_f__Sordariaceae(0.12%~31.63%)、念球菌属(1.30%~17.32%)、曲霉属(2.57%~8.98%)、青霉属(2.88%~9.76%)和丝壳属(0.89%~4.18%)等属真菌占主导地位。发酵过程中,嗜热链球菌属、念球菌属、曲霉属、青霉属等属丰度在发酵的早、中期呈上升趋势,后期下降;嗜热链球菌属和青霉属真菌相对丰度于发酵中期达到高峰。氨气排放与堆体温度为发酵终点关键指标,冗余分析真菌群落与氨气排放和堆体温度的相关性表明,嗜热链球菌属、青霉属和念球菌属丰度与发酵温度和氨气排放呈正相关,其丰度越高,二次发酵周期短且发酵质量优。

In order to clarify the microbial dynamics and diversity during the secondary fermentation of Agaricus bisporus cultivation substrate,the high-throughput sequencing technology was used to determine the changes of fungal community structure during the secondary fermentation of Agaricus bisporus cultivation substrate,and to explore the relationship between community composition and environmental factors.The results showed that the total number of fungal taxonomic units(OTUs)in the four fermentation stages of the secondary fermentation process of Agaricus bisporus cultivation substrate was 999,including 10 phyla,26 classes,56 orders,126 families,240 genera,and 403 species.Among them,the species of Streptococcus thermophilus(12.72%−42.63%),unclassified_f_Sortariaceae(0.12%−31.63%),Candida(1.30%−17.32%),Aspergillus(2.57%−8.98%),Penicillium(2.88%−9.76%),and Kernia(0.89%−4.18%)occupied the dominant position.During the fermentation process,the abundance of fungi belonging to genera such as Streptococcus thermophilus,Candida,Aspergillus,and Penicillium increased at the early and middle stages of fermentation,and then decreased at the later stage.The relative abundance of Streptococcus thermophilus and Penicillium reached the peak in the middle stage of fermentation.Ammonia emission and pile temperature were the key indicators of fermentation end point.The correlation between fungal community and ammonia emission and pile temperature was analyzed by using the redundancy analysis.The results showed that the abundance of Streptococcus thermophilus,Penicillium and Candida was positively correlated with the fermentation temperature and ammonia emission.The higher the abundance was,the shorter the secondary fermentation cycle was and the better the fermentation quality was.