Enhancing Biodegradation of Insoluble High Molecular Weight Polycyclic Aromatic Hydrocarbons in Macroemulsion (ME) Bioreactors with a Liquid–Liquid Interface

Due to the low bioavailability and insolubility of high molecular weight polycyclic aromatic hydrocarbons (HMW-PAHs) in aqueous solutions, their degradation efficiency is significantly limited in wastewater treatment and environmental remediation. To address this challenge, we designed oil-in-water (O/W) macroemulsion (ME) bioreactors with mixed surfactants (Tween-80 and Triton X-100), n-butanol, corn oil, and Burkholderia vietnamiensis (BVs) to enhance the degradation efficiency of pyrene. Owing to the higher solubility of pyrene in MEs, it could be easily adsorbed onto hydrophobic groups on the cell surface. Furthermore, the fluorescence images showed that the BVs were adsorbed on the surface of the MEs, increasing the contact frequency and interactions between pyrene and BVs. Meanwhile, the degradation efficiency of the prepared ME bioreactor was improved by up to 198% compared to that of the conventional surfactant. Therefore, the constructed ME bioreactors can provide green guidance for HMW-PAH biodegradation in industrial wastewater and environmental remediation.