Journal of Bioremediation & Biodegradation

Abstrait

Culture-Independent Analysis of Bacterial Diversity during Bioremediationof Soil Contaminated with a Diesel-Biodiesel Blend (B10)S

Luisa WM, Letícia T, Francielle B, Raquel D, Patricia Dörr de Q, Kateryna Z, Jennifer D, Robson A, Eric WT, Ana Paula GFFAOC and Fatima MB

This study evaluated and compared the degradation of a B10 blend (90% diesel: 10% biodiesel) by native (autochthonous) soil bacteria and exogenous (allochthonous) bacteria. This experiment simulated a surface spill followed by different methods of bioremediation: natural attenuation, bioaugmentation with autochthonous or exogenous bacteria, and biostimulation. The bioremediation process in soil contaminated with B10 (at a rate of 36 g of total petroleum hydrocarbon (TPH) kg-1 of soil) was evaluated for 28 days and analyzed by chromatography (degradation). The heterotrophic and degrading population and fuel mineralization (respirometry) were estimated. The abundance, composition, and diversity of the microbial community resulting from each treatment method were assessed with an ultra-high-throughput sequencing system (Illumina HiSeq). Samples were analyzed at three time points: 1, 15 and 28 days after the contamination. The natural attenuation strategy reduced TPHs by 19%, which suggests a degradation capability of the autochthonous microbial population even when not previously exposed to the contaminant. This genetic feature of the autochthonous population may be due to TPH-degrading plasmids and operons. In bioaugmentation with autochthonous and exogenous bacteria strategy, TPH degradation was similar to that in the other treatments. Proteobacteria, Firmicutes, Acidobacteria, Actinobacteria, Bacteroidetes, and Armatimonadetes were the most abundant phyla post remediation. Natural attenuation presented the highest Fisher’s [alpha] diversity index (at the genus level) at the 28th day post-spill.