Bioremediation of heavy oil contaminated intertidal zones by immobilized bacterial consortium

Heavy oil contamination adversely affects on the intertidal ecological environment and human health. In this study, immobilized bacterial consortium was used in remediating intertidal zones contaminated with heavy oil, and its effectiveness was investigated in simulation experiment pools constructed in the coastal areas. After 100 days, the heavy oil degradation efficiency of immobilized bacterial consortium was 52.99%, which was 13.57% and 30.61% higher than that of biostimulation and natural attenuation, respectively. The immobilized bacterial consortium significantly increased the microbial degradation activity, heavy oil-degrading microbial count, and heavy oil degradation efficiency. Gas Chromatography–Mass Spectrometry results revealed that the biodegradation efficiency of C15–C35 n-alkanes and 2–5-ring polycyclic aromatic hydrocarbons was 25.98–95.80% and 58.93–97.97%, respectively. Microbial community structural analysis showed that Acinetobacter sp. and Bacillus sp. were prominently involved in heavy oil biodegradation. Furthermore, the immobilized bacterial consortium not only resisted the invasion of adverse intertidal environment and promoted the biodegradation of heavy oil pollutants in sediments but also effectively increased the competitiveness between the indigenous oil-degrading microorganisms and other microorganisms. This study can be a promising approach to remediate heavy oil contaminated intertidal zone.