The microbial community profile of a snottite-like biofilm in an abandoned mine drainage tunnel in the Derbyshire Peak District, UK

The formation of biofilms on subterranean surfaces is a topic of significant interest because the characterization of the constituent microorganisms can provide key insights as to the surface biogeochemistry across the micro to nano scale. Stringy biofilms (commonly referred to as snottites) have been described mainly from low pH (0.0 – 1.5) environments. However, stringy biofilms have also been observed in several soughs (lead mine drainage levels) in the Derbyshire Peak District where the surface water is typically near neutral. A snottite-like biofilm that was collected from Yatestoop Sough was visualized microscopically and the microbial community structure determined through DNA extraction and sequencing of the 16S ribosomal RNA genes present. The community contained sulphur-cycling organisms of the genera Thiothrix (16.2%) and Thiobacillus sp (8.7%). The presence of Thiothrix and Thiobacillus might suggest that reduced sulphur within percolating waters could be more influential than is the acidity of these leachates in the formation of snottite-like biofilms.