Impact of diesel and biodiesel contamination on soil microbial community activity and structure

Abstract

Soil contamination as a result of oil spills is a serious issue due to the global demand for diesel fuel. As an alternative to diesel, biodiesel has been introduced based on its high degradability rates and potential for reducing of greenhouse gases emissions. This study assessed the impacts diesel and biodiesel contamination on soil microbial community activity and structure. Our results suggest higher microbial activity in biodiesel contaminated soils and analysis of PLFA profiles confirmed shifts in microbial community structure in response to contamination. High-throughput 16S rRNA amplicon sequencing also revealed a lower bacterial richness and diversity in contaminated soils when compared to control samples, supporting evidence of the detrimental effects of hydrocarbons on soil microbiota. Control samples comprised mostly of Actinobacteria, whereas Proteobacteria were predominantly observed in diesel and biodiesel contaminated soils. At genus level, diesel and biodiesel amendments highly selected for Rhodococcus and Pseudomonas spp., respectively. Moreover, predicted functional profiles based on hydrocarbon-degrading enzymes revealed significant differences between contaminated soils mostly due to the chemical composition of diesel and biodiesel fuel. Here, we also identified that Burkholderiaceae, Novosphingobium, Anaeromyxobacter, Pseudomonas and Rhodococcus were the main bacterial taxa contributing to these enzymes. Together, this study supports the evidence of diesel/biodiesel adverse effects in soil microbial community structure and highlights microbial taxa that could be further investigated for their biodegradation potential.

Microbial contamination of diesel-biodiesel blends in storage tank; an analysis of colony morphology

“…A statistical reduction in microbial counts is also found in pure biodiesel samples (B100) after 50 days of storage. While the microbial activity is detected by Mitter et al [ 47 ] in the first 5 weeks of fuel contamination.…”

The Composition of Diesel Fuel Influences the Structure of Microbiological Assemblages in Contaminated Storage Tanks

“…These primers were selected to amplify a broad distribution of SSU rRNA genes from all three domains of life (44). The forward primer 515F-Y (…”

“…Small subunit (SSU) rRNA gene libraries were generated by amplifying the extracted DNA using PCR primers that spanned the V4 and V5 hypervariable regions of the 16S ribosomal RNA gene between position 515 and 926 ( Escherichia coli numbering), which produced a ∼400 bp fragment for Bacteria and Archaea and ∼600 bp fragments for the Eukarya 18S rRNA gene. These primers were selected to amplify a broad distribution of SSU rRNA genes from all three domains of life (44). The forward primer 515F-Y (5’- GTA AAA CGA CGG CCA GC CG TGY CAG CMG CCG CGG TAA-3’) contains the M13 forward primer (in bold) fused to the gene-specific forward primer (non-bold).…”

“…The availability of different carbon substrates can influence microbial community composition and differences have been observed in diesel and biodiesel fuels as well (41)(42)(43)(44)(45).…”

Effects of Coal and Sewage Sludge Ashes on Macronutrient Content in Maize (Zea mays L.) Grown on Soil Contaminated with Eco-Diesel Oil

“…Diesel oil, made from petroleum, is one of the most widespread soil contaminants [60]. Chemically, it is a mixture of saturated (e.g., paraffin, naphthenic) and aromatic (e.g., naphthalene and its derivatives, toluene, anthracene and phenanthrene) hydrocarbons [61].…”