Water Resources Research Act Program

Details for Project ID 2016NJ377B

A molecular tool to measure dechlorinator activity in situ

Institute: New Jersey
Year Established: 2016 Start Date: 2016-03-01 End Date: 2017-02-28
Total Federal Funds: $19,724 Total Non-Federal Funds: $39,640

Principal Investigators: Valdis Krumins, Donna E. Fennell

Abstract: This research addresses a critical water resource issue in New Jersey: contamination by chlorinated organic (organohalide) pollutants. One of the few removal mechanisms for these pollutants in the environment is reductive dehalogenation by Dehalococcoides mccartyi and similar anaerobic, organohalide respiring bacteria, yet molecular tools to assess activity of these beneficial microbes are limited. The published genomes of Dehalococcoides species have numerous putative reductive dehalogenase genes, though the function has been established only for those responsible for dechlorination of chlorinated ethenes, chlorinated benzenes, 1,2-dichloropropane, and polychlorinated biphenyls (PCBs). Dehalococcoides is known to dechlorinate a wide range of compounds,including Clean Water Act toxic and priority pollutants and others for which the functional genes have not yet been identified. We will determine the relationship between the ribosomal RNA (rRNA) content of D. mccartyi 195 and its growth rate to develop a tool to indicate dehalogenating activity in situ. 16S rRNA content has been shown to be linearly related to growth for a variety of bacteria. We will grow mixed cultures of D. mccartyi 195 in semi-continuous ‘chemostat’ reactors fed trichloroethene at dilution (growth) rates of 0.01 d-1 to 0.1 d-1 to establish the species-specific rRNAgrowth rate curve for this bacterium. The relationship will be tested in reactors fed tetrachlorobenzene, pentachloronitrobenzene, and PCB 114 at a dilution rate of 0.02 d-1. This research will result in a general tool to assess Dehalococcoides found in situ for activity toward diverse contaminants.