Kirsti M. Ritalahti Senior Research Scientist Environmental Engineering Georgia Institute of Technology

Kirsti Ritalahti earned a B.S. in Microbiology from Oregon State University and following her interest in the roles of bacteria play in the environment, she pursued a Ph.D. from the Center for Microbial Ecology at Michigan State University. Currently, she is the Senior Research Scientist in Dr. Löffler’s laboratory at Georgia Tech, exploring reductively dechloirnating bacteria and providing laboratory instruction and student training.  Her research projects aim to identify additional relevant biomarkers in Dehalococcoides organisms, and explore their evolution and interactions with other community members.

Presentation Description
Successful bioremediation of sites contaminated with chlorinated solvents depends on the presence and abundance of critical bacterial populations, such as Dehalococcoides (Dhc)species. Nucleic acid-based, quantitative real-time Polymerase Chain Reaction (qPCR) techniques target Dhc-specific genes, including the 16S rRNA gene and reductive dechlorinase genes (e.g., tceAB, bvcA, and vcrA) implicated in reductive dechlorination of chlorinated ethenes.  In order to draw meaningful conclusions obtained from molecular biological tools (MBTs) applied to groundwater analysis, the quantitative results obtained must accurately reflect the in-situ abundance of the microbial targets. Consequently, the methods used to collect and transport groundwater samples, as well as the variability surrounding DNA collection and storage must be understood and evaluated. We used artificially constructed groundwater and groundwater collected from contaminated sites to develop optimized procedures for sample collection, shipping and nucleic acid biomarker quantification.  A major improvement of the new procedure is the ability to collect biomass on-site, thus avoiding the complications and biases associated with groundwater shipping.