south Wales coalfield microbial communities

Pyrite oxidation drives iron (Fe) and sulphur (S) availability across Earth's biomes and is partly microbially mediated. In situ bacterial community structure can thus either enhance pyrite weathering or act as a biogeochemical bottleneck in iron and sulphur elemental cycles. However, spatio-temporal understanding of community structure and associated biogeochemical reactions in Fe- and S-rich lithologies, such as pyritic coal, is limited. Here we present the first comprehensive regional and seasonal survey of genus-level community structure in a coalfield aquifer, in the South Wales Coalfield (SWC), using 16S rRNA gene amplicon sequencing. Seasonal changes in community structure were generally limited, suggesting surface water and surface derived microbial communities had limited impact on subsurface communities. However, hydrochemically and hydrologically distinct mine water blocks largely explained bacterial community structure variation across sites.