Environmental Genomics of Bacterial Communities Regulating Acid Mine Drainage Neutralization in Wetland Bioreactors
Team: Jeffrey White, Ursel Schütte, Tracy Branam, Greg Olyphant, Indiana University
Wetland bioreactors are a popular method for in-situ treatment of acid mine drainage (AMD). The processes that generate biogenic alkalinity and sequester metals are microbially-catalyzed by a consortium of bacteria colonizing the fill material. The microbial consortium operates under anoxic conditions and drives a suite of oxidation/reduction reactions that derive reducing power from the organic matrix. Biodegradation of the organic matter yields carbon substrates/electron donors for iron- and sulfate-reducing bacteria. Although the general biogeochemistry of these systems is understood, microbial dynamics are often completely ignored. And yet the microbes are the engine of the technology. Making design and operational decisions in the absence of information about the microbial components is akin to flying partially blind.
We are using high through-put sequencing technology provided by the Center for Genomics and Bioinformatics at Indiana University to characterize the temporal and spatial dynamics of bacterial communities in a wetland bioreactor treating AMD, beginning at its inception. We couple environmental genomics with biogeochemical analyses to understand how the microbial community is linked to differences in biogenic alkalinity production within the bioreactor. This study will provide critical information about the functioning of the bioreactor with time that will be useful in the development of strategies for rejuvenation of the reactor in order to extend the functional lifetime of the system.