Fig. 1

Overview of the physicochemical and microbial features of Lake A. a General location and photograph of Lake A. b Physicochemical profiles in the lake. Photosynthetically active radiation data are derived from Charvet et al. 2012, SO₄²⁻, H₂S, total Mn and total Fe were extrapolated from Gibson et al. 2002. c NMDS of the bacterial community based on Bray-Curtis dissimilarity index calculated with 16S rRNA amplicons and metagenomic datasets. d Relative bacterial abundance (qPCR) and community composition based on 16S rRNA genes from metagenomes. The size of the circles represents the relative abundance of genes for each lineage. Only lineages with relative proportions > 1% of the reads in at least one sample are shown. Overall size of the community and associated qPCR bar is related to qPCR data. qPCR data are expressed in number of 16S rRNA genes per mL of lake water