Natural sources and microbial transformation of marine halogenated pollutants

天然多溴有机化合物，如羟基多溴联苯醚(OH-BDEs)和多溴吡咯(PBPs)，最近已成为人类健康关注的化学物质。这些人造卤化持久性有机污染物(POPs)的天然产物亲属广泛分布于整个海洋食物网，并在人类消费的海产品来源中积累。研究人员已经证明，6-OH-BDE-47(甲状腺激素受体)等羟基BDEs和四溴吡咯(Ryanodine Receptor)等多溴联苯并苯酚(PBPs)是有效的毒素，因此对人类构成潜在危险。然而，许多基本问题仍然存在，如这些天然有机溴分子的来源范围，这些化学品如何进入和通过海洋食物网，气候变化是否会影响它们的生产和积累，以及与人造持久性有机污染物相比，人类受到天然卤化持久性有机污染物的影响是更大还是更小。该项目致力于推进新出现的海洋污染物的生物和化学研究。更好地了解这些化合物的来源和汇将提高公众对海洋与人类健康之间联系的了解，并有助于改进关于鱼类消费和健康的指导方针和基于证据的政策。该项目将资助一名研究生和一名博士后研究员。该项目由NSF和国家环境健康科学研究所(NIEHS)共同支持。这些研究人员最近的发现严格建立了不同海洋细菌谱系中天然OH-BDE分子的微生物合成的遗传和生化基础。然而，这些多溴持久性有机污染物在海洋生物群中的全球分布和普遍存在不能用迄今发现的来源完全解释，这表明存在其他生物来源，并正在积极促进海洋食物网中OH-BDE和MeO-BDE的积累。这些信息对于更准确地确定营养连接和相互转换是至关重要的，这些连接和相互转换导致海水鱼类中多溴二苯醚的自然积累，并最终导致人类饮食暴露风险。在这个项目中，将利用转录组分析和生化酶特性相结合的方法，为海洋大型藻类建立新的遗传和生化证据，以证明多溴二苯醚分子的生物合成和生物转化。海洋大型藻类是海洋生境中多溴二苯醚分子的显著来源，但尚未确定其特征。用于多溴二苯醚合成/转化的其他微生物来源的特点将是使用整合的基因组和代谢方法结合用多溴二苯醚分子或生物合成底物修改的实验微生物组浓缩反应器对鱼类和海洋哺乳动物相关微生物进行全面分析。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Natural polybrominated organic compounds such as hydroxylated polybrominated diphenyl ethers (OH-BDEs) and polybrominated pyrroles (PBPs) have recently emerged as chemicals of human health concern. These natural product relatives of man-made halogenated persistent organic pollutants (POPs) are widely distributed throughout the marine food web and accumulate in seafood sources consumed by humans. Researchers have demonstrated that OH-BDEs such as 6-OH-BDE-47 (thyroid hormone receptor) and PBPs such as tetrabromopyrrole (ryanodine receptor) are potent toxins and thus pose a potential risk to humans. Many fundamental questions however remain about the extent of sources for these natural organobromine molecules, how these chemicals enter and move through the marine food web, whether changes in the climate will impact their production and accumulation, and whether humans are more or less impacted by natural halogenated POPs versus their man-made counterparts. This project seeks to advance the biology and chemistry of marine contaminants of emerging concern. A better understanding of the sources and sinks of these compounds will improve public understanding about links between oceans and human health and help improve guidelines and evidence-based policies regarding fish consumption and health. The project will support a graduate student and a postdoctoral researcher. The project is jointly supported by NSF and by the National Institute for Environmental Health Sciences (NIEHS).Recent discoveries by these investigators have rigorously established the genetic and biochemical basis for the microbial synthesis of natural OH-BDE molecules in diverse lineages of marine bacteria. However, the global distribution and ubiquity of these polybrominated POPs in marine biota cannot be fully explained by the sources discovered thus far, suggesting additional biogenic sources exist and are actively contributing to OH-BDE and MeO-BDE accumulation in the marine food web. This information is critical to more accurately identify trophic connections and interconversions that lead to natural PBDE accumulation in marine fish and ultimately, human dietary exposure risks. In this project, new genetic and biochemical evidence for the biosynthesis and biotransformation of PBDE molecules will be established for marine macroalgae, a conspicuous but uncharacterized source of PBDE molecules in marine habitats, using transcriptome analysis coupled with biochemical enzyme characterization. Additional microbial sources for PBDE synthesis/transformation will be characterized by the comprehensive analysis of fish and marine-mammal associated microbiomes using integrated genomic and metabolomic approaches combined with experimental microbiome enrichment reactors amended with PBDE molecules or biosynthetic substrates.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.