Detoxification effect of single inoculation and co-inoculation of Oudemansiella radicata and Serratia marcescens on Pb and fluoranthene co-contaminated soil

Abstract

PURPOSE: In this study, the pot experiments were performed to investigate that Pb and fluoranthene toxicity can be reduced and soil biological properties in co-contaminated soil can be improved by Oudemansiella radicata (O. radicata) combining with Serratia marcescens (S. marcescens). MATERIALS AND METHODS: The soil used in this study was air-dried in 25 °C and sieved through a 2-mm mesh sieve, then was artificially contaminated with the different concentrations Pb. The microbial counts, the ligninolytic enzymes (Laccase and MnP), and soil enzymes (dehydrogenase and acid phosphatase) were analyzed by different methods. The Pb accumulation in mushroom and soils samples were analyzed by using the flame atomic absorption spectrometry (FAAS, SpectrAA-220Fs, United States Varian, Inc.). Fluoranthene content was analyzed using gas chromatograph-mass spectroscopy (GC–MS, Agilent 6890, USA). RESULTS AND DISCUSSION: Results showed that Pb and fluoranthene had a negative effect on soil biological properties and mushroom. S. marcescens inoculation and O. radicata cultivation mitigated the adverse impact and improved the soil biological characteristics. S. marcescens inoculation could significantly increase the percentage of HOAc-extractable Pb and Pb concentration in O. radicata. Meanwhile, O. radicata and S. marcescens inoculation in soil could accelerate the removal of fluoranthene, and removal rate of fluoranthene was 86.39–91.95% in inoculated groups compared to 71.46–81.76% of non-inoculated groups (P < 0.05). This study demonstrated that the interaction of O. radicata and S. marcescens was effective in promoting the bioremediation of co-contaminated soil with Pb and fluoranthene, and thus making it easier for us to detoxify the pollutants. CONCLUSIONS: This study investigated that potential of O. radicata and S. marcescen on the bioremediation of Pb-fluoranthene co-contaminated soil. The combined effect of O. radicata and S. marcescen could significantly promote the bioremediation of Pb-fluoranthene co-contaminated soil, especially for the twice inoculation of S. marcescen groups. These results demonstrated that the presence of O. radicata and S. marcescen could significantly promote the bioremediation of Pb-fluoranthene co-contaminated soil, especially for the twice inoculation of S. marcescen groups.