ERASE-PFAS: Microbial electrochemical defluorination of PFAS using bioaugmented Acidmicrobium sp. Strain A6

ERASE-PFAS：使用生物增强的 Acidmicrobium sp 对 PFAS 进行微生物电化学脱氟。

• 批准号: 2055015
• 负责人: Peter Jaffe
• 金额: $ 40万
• 依托单位: Princeton University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-06-01 至 2025-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2055015&HistoricalAwards=false
• 关键词: ERASE; PFAS; Microbial; electrochemical; defluorination

Per and polyfluorinated alkyl substances (PFAS) are emerging contaminants of concern because they are ubiquitous and have been linked to multiple health problems, including cancer. PFAS are extremely stable, and those of most concern have been considered non-biodegradable. This stability has led to these compounds being dubbed “forever chemicals.” Recently, the bacterium Acidimicrobium (A6) commonly found in acidic iron rich soils has been shown to degrade PFAS. A6 uses ammonia for energy by reaction with solid-phase iron oxides. Although iron oxides are common in soils, adding them to bioreactors for the controlled growth of A6 is challenging. To address these challenges, a special bioelectrochemical reactor was developed with iron serving as the anode. The goal of this project is to gain a fundamental understanding of how A6 degrades PFAS. This will be achieved through testing A6 with various PFAS and operational conditions using the specially formulated bioelectrochemical reactors to understand the mechanisms of PFAS biodegradation. Successful completion of this research will allow the rapid growth of A6 for subsequent addition (“bioaugmentation”) of A6 into contaminated soils to treat PFAS on site, or through direct treatment of PFAS-contaminated water in the bioreactors. This project will train graduate students, undergraduate students, and involve STEM high school students during summer internships in the novel field of PFAS treatment. Results will be disseminated in scientific journals and conferences to advance knowledge. Outreach efforts are focused on advancing acceptance of this novel treatment technology through collaboration with a company to implement a demonstration project for testing in real world applications. Acidimicrobium sp. Strain A6 (A6) is a novel autotrophic Gram-positive bacterium that oxidizes ammonium while reducing iron. A6 is capable of defluorinating PFAS, including perfluorinated compounds such as PFOA and PFOS. The genome of A6 contains dehalogenase genes, including a reductive dehalogenase homolog and a fluoroacetate dehalogenase homolog that are both expressed when PFAS are defluorinated. The high demand of A6 for ferric iron makes it challenging to grow this strain in traditional bioreactors for extended periods of time. Fortunately, A6 is electrogenic and can grow in the absence of iron in microbial electrolysis cells, where it is also able to defluorinate PFOA. This novel research focuses first on understanding the mechanisms by which A6 grows in bioelectrochemical systems. PFAS defluorination will be examined using both pure and enrichment cultures while tracking gene expression and degradation intermediates. Bioreactor results will be combined with results from batch incubations, and a separate collaboration with enzymologists to gain new insights into the mechanisms of PFAS defluorination by A6. The project will train a PhD student and result in close collaboration between students from multiple laboratories to increase cross disciplinary collaboration. Summer engineering and high school interns will be recruited to work in the laboratories to increase STEM training. A collaboration with an industrial partner will implement a pilot demonstration of A6 bioaugmentation to degrade PFAS in industrial waste to facilitate implementation of these findings in the remediation field.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.

全氟和多氟烷基物质（PFAS）是令人关注的新兴污染物，因为它们无处不在，并与多种健康问题有关，包括癌症。PFAS非常稳定，最受关注的PFAS被认为是不可生物降解的。这种稳定性导致这些化合物被称为“永久化学品”。 最近，在酸性富铁土壤中常见的细菌Acidimicrobium（A6）已被证明可以降解PFAS。A6通过与固相氧化铁反应使用氨作为能源。虽然氧化铁在土壤中很常见，但将它们添加到生物反应器中以控制A6的生长是具有挑战性的。为了应对这些挑战，开发了一种特殊的生物电化学反应器，以铁作为阳极。该项目的目标是获得A6如何降解PFAS的基本了解。这将通过测试A6与各种PFAS和操作条件下使用专门配制的生物电化学反应器，以了解PFAS生物降解的机制。这项研究的成功完成将允许A6的快速生长，随后将A6添加到受污染的土壤中（“生物强化”），以现场处理PFAS，或通过生物反应器直接处理PFAS污染的水。该项目将培训研究生，本科生，并在PFAS治疗新领域的暑期实习期间让STEM高中生参与。研究结果将在科学期刊和会议上传播，以增进知识。外联工作的重点是通过与一家公司合作，实施一个示范项目，在真实的世界应用中进行测试，从而提高人们对这种新型处理技术的接受程度。Acidimicrobium sp. Strain A6（A6）是一株新的自养革兰氏阳性细菌，能氧化铵，同时还原铁。A6能够对全氟辛烷磺酸进行脱氟，包括全氟辛酸和全氟辛烷磺酸等全氟化合物。A6的基因组含有脱卤酶基因，包括还原脱卤酶同源物和氟乙酸脱卤酶同源物，当PFAS脱氟时，两者都表达。A6对三价铁的高需求使得在传统生物反应器中长时间培养这种菌株具有挑战性。幸运的是，A6是产电的，可以在没有铁的情况下在微生物电解池中生长，在那里它也能够使PFOA脱氟。这项新的研究首先侧重于了解A6在生物电化学系统中生长的机制。将使用纯培养物和富集培养物检查PFAS去磷，同时跟踪基因表达和降解中间体。生物反应器的结果将与批次孵育的结果相结合，并与酶学家单独合作，以获得对A6降解PFAS机制的新见解。该项目将培养一名博士生，并导致来自多个实验室的学生之间的密切合作，以增加跨学科的合作。暑期工程和高中实习生将被招募到实验室工作，以增加STEM培训。与工业合作伙伴的合作将实施A6生物强化的试点示范，以降解工业废物中的PFAS，以促进这些发现在补救领域的实施。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。