Fig. 2. Community composition and key pathways of Sulfurihydrogenibium-dominated hydrothermal streamers.

Relative abundance is shown for biofilm metagenome from vent sample 2016_B01, which was the cleanest unmanipulated sample retrieved (the relative abundance of other samples is provided in Supplementary Table 1). Concentrations of H₂, H₂S, and CO₂ were previously determined for YLake vents in the Deep Hole [33, 35, 39]. Arrows either represent (i) autotrophic pathways, (ii) enzymatic conversions between sulfur species, or (iii) hydrogenases. Arrow color corresponds to the microbial lineage encoding that particular enzyme; arrow thickness is weighted by mean coverage for the contig containing the relevant gene/s. [apr = adenylylsulfate reductase; sat = sulfate adenylyltransferase; cys = adenylylsulfate kinase; phs = polysulfide reductase; dsr = dissimilatory sulfite reductase; sdo = sulfur dioxygenase; sre = sulfur reductase; sqr = sulfide:quinone oxidoreductase].