Title Effect of biostimulation and bioaugmentation on hydrocarbon degradation and detoxification of diesel-contaminated soil: a microcosm study
Author Patricia Giovanella1, Lídia de Azevedo Duarte1, Daniela Mayumi Kita1, Valéria Maia de Oliveira2, and Lara Durães Sette1*
Address 1São Paulo State University (UNESP), Institute of Biosciences, Department of General and Applied Biology, Laboratory of Environmental and Industrial Mycology, Rio Claro (SP) 01049-010, Brazil, 2State University of Campinas (UNICAMP), Research Center for Chemistry, Biology, and Agriculture, Microbial Resources Division, Campinas (SP) 13083-970, Brazil
Bibliography Journal of Microbiology, 59(7),634–643, 2021,
DOI 10.1007/s12275-021-0395-2
Key Words biostimulation, fungi, bacteria, hydrocarbon degradation, detoxification
Abstract Soil contamination with diesel oil is quite common during processes of transport and storage. Bioremediation is considered a safe, economical, and environmentally friendly approach for contaminated soil treatment. In this context, studies using hydrocarbon bioremediation have focused on total petroleum hydrocarbon (TPH) analysis to assess process effectiveness, while ecotoxicity has been neglected. Thus, this study aimed to select a microbial consortium capable of detoxifying diesel oil and apply this consortium to the bioremediation of soil contaminated with this environmental pollutant through different bioremediation approaches. Gas chromatography (GC-FID) was used to analyze diesel oil degradation, while ecotoxicological bioassays with the bioindicators Artemia sp., Aliivibrio fischeri (Microtox), and Cucumis sativus were used to assess detoxification. After 90 days of bioremediation, we found that the biostimulation and biostimulation/ bioaugmentation approaches showed higher rates of diesel oil degradation in relation to natural attenuation (41.9 and 26.7%, respectively). Phytotoxicity increased in the biostimulation and biostimulation/bioaugmentation treatments during the degradation process, whereas in the Microtox test, the toxicity was the same in these treatments as that in the natural attenuation treatment. In both the phytotoxicity and Microtox tests, bioaugmentation treatment showed lower toxicity. However, compared with natural attenuation, this approach did not show satisfactory hydrocarbon degradation. Based on the microcosm experiments results, we conclude that a broader analysis of the success of bioremediation requires the performance of toxicity bioassays.