Analysis of the Impact of Acid Mine Drainage on Bacterial Populations in the Upper Tioga Watershed

The Upper Tioga Watershed (UTW) in northern Pennsylvania is exposed to acid mine drainage (AMD), resulting in decreased population sizes and diversity of macrobiota. Few studies thus far, however, have assessed the impact of AMD on the microbial communities in streams receiving AMD. Using taxonomic (terminal restriction fragment length polymorphisms (T-RFLP)) and metabolic (Biolog EcoPlates) analyses, bacterial biodiversity and community structure in AMD-impacted and non-impacted sites of the UTW were compared. The results indicate that bacterial communities in sediments of streams receiving AMD differ from those at a non-impacted site and are less diverse. Analysis of T-RFLP patterns and metabolic patterns from Biolog EcoPlates revealed two main clusters of community similarity among the sites. The pattern suggests that the bacterial communities may be more resistant to negative effects of AMD than macroscopic organisms. One AMD-impacted site is dominated by one taxonomic group, putatively identified as Beijerinckiaceae.