Natural Microbial Communities within In-Field Bioreactors Targeted loci environmental

One of the most difficult aspects of studying microbial ecology is determining the fundamental ties between temporal fluctuations in environmental conditions and microbial community structure. While microorganisms are important as the foundation for ecosystem health affecting local geochemistry and contaminant fate, it is difficult to link the response of microbial species within complex communities to perturbations. Hence, it is important to develop methods to interrogate microbial communities so that linkages between biodiversity and function may be established. We have developed a novel in-field bioreactor system for manipulating the in-situ conditions and monitoring the response of the groundwater microbial community to altered geochemistry. Large, expensive systems designed for the treatment of groundwater contamination are not well suited for testing theories regarding the influence of contaminants or more common geochemical parameters on community structure and subsequent function. The bioreactors in this study are much smaller, allowing for experimental replication and can differentiate between planktonic and attached communities. The purpose of this study was to demonstrate the feasibility of manipulating the geochemical conditions within in-field bioreactors in order to capture the response of the microbial community. This work shows the viability of in-field bioreactors as an approach for understanding drivers of the microbial communities in groundwater.