Enhanced bioremediation of cyclohexaneacetic acid in offshore sediments with green synthetic iron oxide and Pseudoalteromonas sp.

Naphthenic acids (NAs) have been found to exert serious threats on offshore sediment ecosystems and human health in recent years, which entails us the urgent need for NAs remediation. Bioremediation is considered an ideal method for sediment remediation due to ecological sustainability and economic feasibility. However, current bioremediation efficiency of offshore sediments suffers from relatively slow and there has never any attempts to bioremediate offshore sediment NAs contamination hitherto. In this study, the green synthetic iron oxides (gFeOx) based on Laminaria extracts was employed to enhance the biodegradation of NAs (Cyclohexylacetic acid, CHAA) in offshore sediments by Pseudoalteromonas sp. JSTW (an indigenous microorganism). The results showed that CHAA (20 mg·kg-1) in offshore sediments was removed almost 100% within 7 days at 30 mg·kg-1 gFeOx and 0.6 mg·kg-1 Strain JSTW. High-throughput sequencing results revealed that the structure and function of sediment microbial community were essentially restored to uncontaminated levels after bioremediation, highlighting the joint remediation approach is an efficient and eco-friendly method. Overall, this work has firstly provided insights into the application for NAs in situ bioremediation in offshore sediments.