Friday, August 4, 2023

Polycyclic aromatic hydrocarbons (PAHs) are a class of environmental contaminants associated with carcinogenic, mutagenic, and teratogenic health effects. Bioremediation is an attractive option for PAH remediation due to its low cost and low energy requirements, however bioremediation can lead to the formation of toxic PAH transformation products. In pursuit of novel bioremediation strategies, exploratory work was conducted with the pure bacterial culture Rhodococcus rhodochrous ATCC 21198 and monoaromatic hydrocarbons (BTEX), which provided the foundation for PAH bioremediation strategies. PAH bioremediation studies required monitoring methods that could provide results in real-time, which traditional analytical techniques could not provide. Thus, a method for rapid analysis of PAHs in aqueous samples was developed using excitation-emission matrix (EEM) fluorescent spectroscopy and parallel factor analysis (PARAFAC) that eliminated the need for extensive sample preparation and separation techniques before analysis. This work also inspired additional method development endeavors for a more complex biological system: embryonic zebrafish. Following the foundational microbial work and method development research phases, our work in PAH remediation technologies has commenced and expanded to include surfactants and immobilized cells for combined remediation strategies. Metrics for remediation success included reduction of parent PAH concentrations, accumulation of PAH metabolites, and overall toxicity of the treated material. Outcomes of this research has demonstrated the utility of 21198 as a candidate for aromatic hydrocarbon bioremediation, provided a new tool for monitoring aqueous PAH concentrations in biological systems, and highlighted the importance of toxicity considerations in PAH remediation efforts.