Relating microbial community and physicochemical parameters of a hot spring: Champagne pool, wai-o-tapu, New Zealand

Champagne Pool, located in the Wai-o-tapu geothermal area of New Zealand, is a moderately acidic, chloride hot spring. Samples were collected from four geochemically distinct zones along the margin of the pool that include: sub-aqueous precipitates (75 °C, pH 5.5); elemental sulfur at the air/water interface; sub-aerial sinter and an acid-organic deposit (pH 2.5) that coats the older sinter. A 16S rRNA gene analysis of these samples was used to distinguish the microbial communities present, of which two distinct communities were identified. The sub-aqueous precipitate, sulfur and microstromatolites showed a predominance of phylotypes related to hydrogen and sulfur-respiring thermophilic microorganisms. The acid-organic material supports an acidophilic mesophilic microbial community with phylotypes related to heterotrophic and phototrophic microorganisms. The microbial community composition reflected the physicochemical conditions active in each sample zone.