由于人类活动,南极洲的陆地燃料泄漏通常发生在研究站周围的无冰土地上。成功的溢油清理需要适当的目标,以确认受污染的场所在补救后不再可能构成环境风险。这些目标基于对污染物对土壤生态系统的影响以及本地生物群对污染的响应的了解。我们的工作通过测量关键土壤过程中涉及的基因的丰度来检查土壤微生物群落对燃料污染的响应,并评估了在存在风化和新鲜燃料的情况下将这种方法用作土壤健康指标的情况。未污染和污染的土壤是从Casey站老化柴油泄漏的修复处理现场收集的,2012年12月东南极洲。在未受污染的土壤中掺入新鲜的特殊南极混合物(SAB)柴油,以确定基因对新鲜燃料的响应。用未污染的土壤稀释含有风化SAB柴油的部分修复土壤,以模拟一系列风化燃料的浓度,并用于确定基因对老化燃料的响应。定量PCR(qPCR)用于测量rpoB的丰度,alkB,含有SAB柴油的土壤中的cat23和nosZ。观察到对照土壤与含有风化和新鲜燃料的土壤中基因丰度之间的差异。响应于新鲜燃料的存在,针对基因产生典型的剂量-响应曲线。相比之下,这些基因对风化燃料范围的反应似乎是由于稀释,而不是燃料对微生物群落的影响。微生物基因响应新鲜污染的变化有可能作为土壤健康的敏感量度和评估极地土壤中燃料泄漏的影响。这将有助于制定补救指南,以协助管理决策何时需要对燃料泄漏的影响进行补救。
Terrestrial fuel spills in Antarctica commonly occur on ice-free land around research stations as the result of human activities. Successful spill clean-ups require appropriate targets that confirm contaminated sites are no longer likely to pose environmental risk following remediation. These targets are based on knowledge of the impacts of contaminants on the soil ecosystem and on the response of native biota to contamination. Our work examined the response of soil microbial communities to fuel contamination by measuring the abundance of genes involved in critical soil processes, and assessed the use of this approach as an indicator of soil health in the presence of weathered and fresh fuels. Uncontaminated and contaminated soils were collected from the site of remediation treatment of an aged diesel spill at Casey Station, East Antarctica in December 2012. Uncontaminated soil was spiked with fresh Special
Antarctic Blend (SAB) diesel to determine the response of the genes to fresh fuel. Partly remediated soil containing weathered SAB diesel was diluted with uncontaminated soil to simulate a range of concentrations of weathered fuel and used to determine the response of the genes to aged fuel. Quantitative PCR (qPCR) was used to measure the abundance of rpoB, alkB, cat23, and nosZ in soils containing SAB diesel. Differences were observed between the abundance of genes in control soils versus soils containing weathered and fresh fuels. Typical dose-response curves were generated for genes in response to the presence of fresh fuel. In contrast, the response of these genes to the range of weathered fuel appeared to be due to dilution, rather than to the effect of the fuel on the microbial community. Changes in microbial genes in response to fresh contamination have potential as a sensitive measure of soil health and for assessments of the effect of fuel spills in polar soils. This will contribute to the development of remediation
guidelines to assist in management decisions on when the impact of a fuel spill warrants remediation.