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，它可以阻止对共存的高优先级污染物（如氯化溶剂）的修复。因此，了解受污染场地的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。该研究的目的是鉴定微生物介导的1,4-二恶烷降解的生物标志物，并开发1,4-二恶烷降解富集培养物作为潜在的生物修复工具。这项工作将包括实地采样两个1,4-二恶烷污染的地点-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。环境微生物将通过宏基因组测序进行表征，并培养1,4-二氧嘧啶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识别出来，从而确定全球范围内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。基于二恶烷的毒性和普遍性，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大污染物水平。因此，开发生物标志物来评估1,4-二恶烷降解的潜力和建立生物修复工具是确保加拿大政策制定者和场地所有者对最新确定的最大污染物水平做出快速、适当反应的积极步骤。

1,4-dioxane is a common groundwater contaminant and likely human carcinogen. As such, 1,4-dioxanerepresents an environmental and human health hazard. Dioxane is a common co-contaminant in many activeand retired industrial sites where it can prevent remediation of co-occurring, high-priority contaminants such aschlorinated solvents. Understanding the capacity for 1,4-dioxane attenuation and bioremediation at acontaminated 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-dioxanedegradation 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 aformer chemical plant in Southeast Texas. Microbial biomass will be filtered from landfill leachate andgroundwater. Environmental microbes will be characterized through metagenomic sequencing, and 1,4-dioxanedegraders cultivated and their activities characterized. Genes involved in 1,4-dioxane degradation will beidentified 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 assessmentand access to cost-effective bioremediation options will have strong economic benefits for site owners. Basedon dioxane's toxicity and prevalence, maximum contaminant levels are expected to be implemented byEnvironment Canada and the U.S. Environmental Protection Agency within the next few years. Developmentof biomarkers to assess the potential for 1,4-dioxane degradation and establishment of bioremediation tools arethus proactive steps to ensure Canadian policy makers and site owners have rapid, appropriate responses tonewly established maximum contaminant levels.