Superfund Research Program
Engineering the Physico-Chemical Environment to Enhance the Bioremediation of Developmental Toxicants in Sediment Fungal-Bacterial Biofilms
- Project Summary
Bacterial and fungal microbiomes have been characterized for several sites in the Elizabeth River watershed as well as from the Holcombe Creosote Superfund site where a known gradient of PAH contamination has been documented. Coupling microbial and chemical profiling, Claudia Gunsch, Ph.D., and her team were able to develop a novel precision bioremediation framework that takes advantage of indigenous microbial capacity. However, this framework remains limited for field application due to the innate heterogeneity of soil and sediments and presents a unique challenge for constructing useful microbial association network models for rational in situ microbiome engineering. Current efforts are focused on the development of a mathematical model that can improve field application of microbiome engineering to improve bioremediation capacity. In addition to the modeling work, amendments were tested for their ability to stimulate fungal degradation of polycyclic aromatic hydrocarons (PAHs) in simple aqueous reactors as well as more complex sediment reactors. Those data suggest that in some instances the amendments may hinder degradation in complex systems suggesting that an improved geochemical characterization is imperative for optimizing the field application of microbiome engineering strategies. Finally, an activated carbon based amendment, SediMite-TM, was tested for its ability to support biofilm growth and inform future field deployment activities. Results from this project suggest that at high chemical concentrations, SediMite-TM can support the growth of the teams engineered bacterial consortium and this approach shows promise for reducing PAH concentrations in contaminated sediments.