The purpose of experimentation was to determine the inhibitory effects of the cis form of 1,2-Dichloroethene (cis-DCE), a widespread toxic chlorinated solvent contaminant, on the growth of the aerobic bacteria Rhodococcus rhodochrous ATCC® 21198, as well as to determine the rate of Rhodococcus rhodochrous cometabolic degradation of cis-DCE with and without the presence of the primary growth substrate isobutane. R. rhodochrous’ unique metabolic capabilities presented a promising alternative to current decontamination methodology. Growth Reactors were designed to determine if cis-DCE induced any inhibitory effects on the growth of Rhodococcus rhodochrous. Growth reactors were prepared with 270 mL of nanopure water and bioaugmented with 21198 before cis-DCE was added to one to assess the inhibitory effects of cis-DCE on 21198 growth. The Substrate Inhibition Test sought to determine how the rate of cis-DCE cometabolism is affected with and without the presence of the primary growth substrate isobutane. A rate test was conducted with three 27 mL vials prepared with MV media and injected with cis-DCE with 21198 in vials 1 and 2 and isobutane in vials 2 and 3. When compared to standard curves of isobutane and cis-DCE, it was found that the growth reactors performed similarly both with and without cis-DCE. It was also determined that the cometabolism of cis-DCE by 21198 was more efficient without the presence of isobutane, since the cometabolism of cis-DCE in the vials without isobutane occurred more rapidly. This study has numerous implications in the field of contaminant hydrology.
Air Force Research Laboratory on behalf of the United States Air Force: First Award of $750 in each Intel ISEF Category