Supporting Information S1 - Unraveling the Stratification of an Iron-Oxidizing Microbial Mat by Metatranscriptomics

File contains Figures S1–S5 and Tables S1–S3. Figure S1: Methane concentrations measured at the sampling sites. Methane concentrations were measured at the two sampling sites (U, upstream; D, downstream) in triplicates distinguishing between depth and surface. For two samples (Surface Jan 2013, D; Surface May 2013, D) only a single measurement was available. Higher methane concentrations were measured in corresponding deep samples with one exception in the samples July 2013, U. Surrounding waters without microbial mat observation are shown in grey: Source, water flow directly upstream of the microbial mats; Lake, lake above the stream without microbial mat; River, main stream with stronger water current. Figure S2: Relative abundance of the active eukaryotic members of the microbial community based on the taxonomic affiliation of SSU rRNA transcript matches at the phylum and class levels. The rRNA transcripts from each triplicate were combined and normalized average values are shown. The total numbers of eukaryotic matches included in the analysis are indicated. The large majority of eukaryotic matches are affiliated to Tetrahymenina/Oligohymenophorea that contains essentially freshwater grazers such as Tetrahymena species (ranging from 62.3% to 91.0% of the eukaryotic matches). Figure S3: Scanning electron microscopy of the microbial mat showing typical extracellular sheets (Leptothrix) and stalks (Gallionella). Figure S4: Relative abundance and taxonomic affiliations of OTUs. For illustration purposes standard deviations are indicated as negative or positive bars. Figure S5: Relative abundance of reads matching transcripts coding for the three proteins involved in iron oxidation from Sideroxidans lithotrophicus ES-1. MtrA, mtrB, cymA transcripts from each triplicate were combined and normalized average values are shown (in total 157 matches). Table S1: General characteristics of the microbial mat samples. Table S2: Diversity and richness estimates for the rRNA region analysis. Table S3: Detailed match counts of non-rRNA transcripts to microbial genome sequences. (PDF)