TCE cometabolism by ammonia-oxidizing biofilms grown under near-oligotrophic conditions

Ammonia-oxidizing biofilms are grown on basalt pebbles in stainless steel wire baskets rigidly suspended in Continuous Stirred Tank Catalytic Reactors (CSTCRs). Conditions are kept near oligotrophic to simulate a natural groundwater condition. Characterization of the biofilms using scanning confocal laser microscopy (SCLM), fluorescent in situ hybridization (FISH), activity stains, and total biomass measurements is ongoing. After sufficient biomass is developed, biofilms are transferred to fresh, sealed CSTCRs for kinetics experiments. Biofilm activity during trichloroethylene (TCE) degradation is evaluated by measuring nitrite/nitrate production and ammonia disappearance while TCE degradation is quantified by GC analysis of reactor headspace gas. After TCE exposure, the biofilms are characterized again to ascertain the effects of TCE exposure.