Department of Food and Bioproduct Sciences, University of Saskatchewan, 51 Campus Drive, Saskatoon, SK, S7N 5A8, Canada.
Department of Soil Science, University of Saskatchewan, 51 Campus Drive, Saskatoon, SK, S7N 5A8, Canada.
Sci Rep. 2021 May 25;11(1):10856. doi: 10.1038/s41598-021-89637-y.
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.
由于全球对柴油燃料的需求，石油泄漏导致的土壤污染是一个严重的问题。作为柴油的替代品，生物柴油因其高降解率和减少温室气体排放的潜力而被引入。本研究评估了柴油和生物柴油污染对土壤微生物群落活性和结构的影响。我们的结果表明，生物柴油污染土壤中的微生物活性更高，PLFA 谱分析证实了微生物群落结构因污染而发生变化。高通量 16S rRNA 扩增子测序还表明，与对照样品相比，污染土壤中的细菌丰富度和多样性较低，这支持了碳氢化合物对土壤微生物群有害影响的证据。对照样品主要由放线菌组成，而在柴油和生物柴油污染的土壤中则主要观察到变形菌。在属水平上，柴油和生物柴油的添加物分别高度选择了 Rhodococcus 和 Pseudomonas spp。此外，基于烃类降解酶的预测功能图谱显示，污染土壤之间存在显著差异，这主要是由于柴油和生物柴油燃料的化学成分不同。在这里，我们还确定了伯克霍尔德氏菌科、新鞘氨醇单胞菌属、厌氧粘细菌属、假单胞菌属和红球菌属是对这些酶有主要贡献的细菌分类群。总之，这项研究支持了柴油/生物柴油对土壤微生物群落结构的不利影响的证据，并强调了可能进一步研究其生物降解潜力的微生物分类群。
