Biomarkers and bioremediation solutions for 1,4-dioxane contamination

1,4-二恶烷是一种常见的地下水污染物和可能的人类致癌物。因此，1,4-二恶烷**对环境和人类健康构成危害。二氧六环是一种常见的共污染物，在许多活跃和废弃的工业场所中，它可以阻止对共发生的高优先级污染物（如氯化溶剂）的修复。因此，了解污染场地的1,4-二恶烷衰减和生物修复能力对环境保护机构、场地所有者和公众都很重要。**拟议的研究同时具有确定微生物介导的1,4-二恶烷降解的生物标志物和开发1,4-二恶烷降解富集培养物作为潜在的生物修复工具的目的。这项工作将包括对两个1,4-二恶烷污染地点进行实地采样——安大略省南部的一个垃圾填埋场和德克萨斯州东南部的一个前化工厂。微生物生物量将从垃圾填埋场渗滤液和地下水中过滤。通过宏基因组测序对环境微生物进行表征，培养1,4-二恶烷降解物并对其活性进行表征。参与1,4-二恶烷降解的基因将从采样地点以及来自不同环境的公共宏基因组序列中鉴定出来，**确定全球范围内1,4-二恶烷降解的普遍性和潜力。准确的场地评估**和获得具有成本效益的生物修复方案将为场地所有者带来强大的经济效益。根据二恶烷的毒性和流行程度，加拿大环境部和美国环境保护署预计将在未来几年内实施最高污染物水平。开发生物标记物来评估1,4-二恶烷降解的潜力，并建立生物修复工具，因此是**积极的步骤，以确保加拿大的政策制定者和场地所有者对**新建立的最大污染物水平做出快速，适当的反应。

1,4-dioxane is a common groundwater contaminant and likely human carcinogen. As such, 1,4-dioxane**represents an environmental and human health hazard. Dioxane is a common co-contaminant in many active**and retired industrial sites where it can prevent remediation of co-occurring, high-priority contaminants such as**chlorinated solvents. Understanding the capacity for 1,4-dioxane attenuation and bioremediation at a**contaminated site is thus important to environmental protection agencies, site owners, and the general public.**The proposed research has concurrent aims of identifying biomarkers for microbially-mediated 1,4-dioxane**degradation and development of 1,4-dioxane degrading enrichment cultures as potential bioremediation tools.**The work will include field sampling two 1,4-dioxane contaminated sites - a southern Ontario landfill and a**former chemical plant in Southeast Texas. Microbial biomass will be filtered from landfill leachate and**groundwater. Environmental microbes will be characterized through metagenomic sequencing, and 1,4-dioxane**degraders cultivated and their activities characterized. Genes involved in 1,4-dioxane degradation will be**identified from the sampled sites as well as from public metagenome sequences from diverse environments,**defining the prevalence and potential for 1,4-dioxane degradation across the globe. Accurate site assessment**and access to cost-effective bioremediation options will have strong economic benefits for site owners. Based**on dioxane's toxicity and prevalence, maximum contaminant levels are expected to be implemented by**Environment Canada and the U.S. Environmental Protection Agency within the next few years. Development**of biomarkers to assess the potential for 1,4-dioxane degradation and establishment of bioremediation tools are**thus proactive steps to ensure Canadian policy makers and site owners have rapid, appropriate responses to**newly established maximum contaminant levels.