Bioaugmentation with a consortium of bacterial nitrophenol-degraders for remediation of soil contaminated with three nitrophenol isomers

A consortium consisting of para-nitrophenol utilizer Pseudomonas sp. strain WBC-3, meta-nitrophenol utilizer Cupriavidus necator JMP134 and ortho-nitrophenol utilizer Alcaligenes sp. strain NyZ215 was inoculated into soil contaminated with three nitrophenol isomers for bioaugmentation. Accelerated removal of all nitrophenols was achieved in inoculated soils compared to un-inoculated soils, with complete removal of nitrophenols in inoculated soils occurring between 2 and 16 days. Real-time polymerase chain reaction (PCR) targeting nitrophenol-degradation functional genes indicated that the three strains survived and were stable over the course of the incubation period. The abundance of total indigenous bacteria (measured by 16S rRNA gene real-time PCR) was slightly negatively impacted by the nitrophenol contamination. Denaturing gradient gel electrophoresis profiles of total and group-specific indigenous community suggested a dynamic change in species richness occurred during the bioaugmentation process. Furthermore, Pareto–Lorenz curves and Community organization parameters indicated that the bioaugmentation process had little impact on species evenness within the microbial community.

► Nitrophenol isomers in contaminated soil were removed by a bacterial consortium.
► The inoculated three strains were stable by real-time PCR analysis.
► DGGE profiles suggested a dynamic change in indigenous species richness.
► The bioaugmentation had little impact on indigenous species evenness.