Fig. 4

Composition of fungal communities in different stages of FECM of three sediment samples by means of high-throughput sequencing of fungal amplicons biomarker. a Shannon index of fungal communities. D0–D21 indicate 0, 7, 14, and 21 days of FECM, respectively. The significance of difference was determined by nonparametric Wilcoxon test. b NMDS of fungal communities based on weighted UniFrac metrics from four stages of enrichment cultivation. The significance of factors on community dissimilarity was tested with nested PERMANOVA based on weighted UniFrac distances. D0–D21 indicate 0, 7, 14, and 21 days of FECM, respectively. c Venn diagram of ASVs from different periods of enrichment cultivation. D0–D21 indicate 0, 7, 14, and 21 days of FECM, respectively. d Phylogenetic distribution of 154 abundant taxa, 547 intermediate taxa, and 1024 rare taxa (ASVs with a relative abundance above 0.1% across total sequences were considered as “abundant” taxa, those with relative abundances below 0.01% were considered as “rare” taxa, and those with relative abundances between 0.01 and 0.1% were “intermediate” ASVs). e Difference of phylogenetic diversity among abundant taxa, intermediate taxa, and rare taxa. The significance of difference was determined by nonparametric Wilcoxon test. f Pie plot showing the community compositions of each period of FECM based on the criteria of abundant taxa, intermediate taxa, and rare taxa. D0–D21 indicate 0, 7, 14, and 21 days of FECM, respectively. g Bar plot showing the isolates compositions between DC and FECM based on the criteria of abundant taxa, intermediate taxa, and rare taxa