Collaborative Research: Microbial chain-elongation mediated dehalogenation and carbon transformation

合作研究：微生物链延长介导的脱卤和碳转化

• 批准号: 2221828
• 负责人: Matthew Scarborough
• 金额: $ 21.44万
• 依托单位: University of Vermont & State Agricultural College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2221828&HistoricalAwards=false
• 关键词: Collaborative; Research; Microbial; chain; elongation

Chlorinated solvents consist of a large family of chlorinated hydrocarbons that have been used worldwide in large quantities to support various industrial applications. Chlorinated solvents such as perchloroethylene (PCE) and trichloroethylene (TCE) are among the most ubiquitous groundwater contaminants in the United States and worldwide. Bioremediation using Dehalococcoides mccartyi has emerged as a promising technology to treat groundwater contaminated by PCE and TCE. Dehalococcoides mccartyi are anaerobic microorganisms that can reduce and convert PCE and TCE to ethene which can subsequently be mineralized to carbon dioxide by other anerobic and/or aerobic microorganisms present in groundwater. However, Dehalococcoides mccartyi require the use of hydrogen (H2) as a sole electron donor to convert PCE and TCE to ethene. The overarching goal of this project is to investigate the use of microbial chain elongation-mediated dehalogenation as a novel groundwater bioremediation process that leverages the ability of a consortium of anaerobic microorganisms to produce the amount of H2 required to carry out the reduction and conversion of PCE/TCE to ethene using organic substrates such as lactic acids, molasses, and vegetable oil. The successful completion of this project will benefit society through the generation of new fundamental knowledge to advance the development and implementation of more efficient and cost-effective bioremediation technologies for the treatment of groundwater contaminated by chlorinated solvents. Additional benefits to society will be achieved through education and outreach activities including the mentoring of two graduate students and two undergraduate students at Arizona State University and the University of Vermont.Dehalococcoides mccartyi are organohalide-respiring bacteria that utilize halogenated compounds as terminal electron acceptors in an anaerobic respiration process to generate the energy required for their growth using electron donors such as hydrogen (H2). During the last two decades, Dehalococcoides mccartyi have emerged as the most promising microorganisms with capability to carry out the reductive dehalogenation of chlorinated hydrocarbons such as perchloroethylene (PCE) and trichloroethylene (TCE) in contaminated groundwater. However, competing microorganisms (e.g., iron or sulfate reducing bacteria) in groundwater that utilize H2 as electron donor can adversely impact the rate and extent of PCE/TCE dehalogenation and conversion to ethene by Dehalococcoides mccartyi. This competition has been consistently linked to slow rates of PCE/TCE dehalogenation and/or the accumulation of toxic intermediates such as vinyl chloride. Building upon the results of promising preliminary studies, the Principal Investigators (PIs) of this project propose to explore the coupling of microbial chain elongation with reductive dehalogenation with the goal of identifying a consortium of anaerobic microorganisms that can reduce and convert PCE/TCE to ethene while using chain elongation to generate the amount of H2 required to carry out this conversion. To advance this goal, the PIs propose to carry out an integrated experimental and modeling research program to 1) uncover critical metabolic pathways and ecological interactions that govern microbial chain elongation-mediated dehalogenation, and 2) develop and validate computational metabolic models of microbial chain elongation coupled with dehalogenation. The specific objectives of the research are to: 1) Characterize the growth and inhibition kinetics and metabolic networks of a consortium of organo-halide respiring and chain-elongating bacteria that has shown promising potential to convert PCE/TEC to ethene and 2) Unravel the interactions of microbial chain elongation with the competing metabolic pathways of methanogenesis and homoacetogenesis in organo-halide respiring microbial communities. The successful completion of this research has the potential for transformative impact through the generation of new fundamental knowledge and computational metabolic models to advance the development and deployment of groundwater bioremediation by microbial chain elongation-mediated dehalogenation. To implement the educational and training goals of this project, the PIs propose to leverage existing programs at their respective institutions to integrate the findings from this research into an RET (Research Experience for Teachers) program at Arizona State University and an extension program (4-H) at the University of Vermont (UVM) to teach and inspire high school teachers and students to explore the use of microorganisms in environmental remediation. In addition, the PIs plan to leverage existing REU (Research Experiences for Undergraduates) programs at ASU and UVM to recruit undergraduate students from underrepresented groups to work on the project.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.

氯化溶剂由大型氯化碳氢化合物组成，这些碳水化合物已在全球范围内大量用于支持各种工业应用。氯乙烯（PCE）和三氯乙烯（TCE）等氯化溶剂是美国和全球范围内最普遍的地下水污染物之一。使用Dehalococoides McCartyi进行生物修复已成为一种有前途的技术，可以治疗受PCE和TCE污染的地下水。去足球菌麦卡蒂（McCartyi）是厌氧微生物，可以将PCE和TCE降低并转化为乙烯，随后可以通过地下水中存在的其他厌食和/或有氧微生物将其矿化为二氧化碳。然而，脱氧核糖核苷McCartyi要求将氢（H2）用作唯一的电子供体将PCE和TCE转换为乙烯。 该项目的总体目标是调查使用微生物链伸长介导的脱核酸作为一种新的地下水生物修复过程，该过程利用了厌氧微生物财团的能力，以产生PCE/TCE/TECE cCE/TECE型杂种型的H2的量，以产生对PCE/TECE的减少和转化的能力。该项目的成功完成将通过产生新的基本知识来使社会受益，从而促进开发和实施更有效，更具成本效益的生物修复技术，以治疗受氯化溶剂污染的地下水。将通过教育和宣传活动来实现社会的其他好处（H2）。在过去的二十年中，脱甲基菌糖苷麦卡蒂（McCartyi）已成为最有希望的微生物，能够在污染的地下水中进行氯化碳氢化合物的还原性去核酸氯化碳酸碳碳（如高氯乙烯（PCE）（PCE）（PCE）和三氯乙烯（TCE）。然而，将H2用作电子供体的地下水中的竞争微生物（例如铁或硫酸盐还原细菌）可能会对Dehalococoides McCartyi的PCE/TCE去盐化的速率和程度产生不利影响。该竞争一直与PCE/TCE去alogenation的缓慢和/或有毒中间体（如乙烯基氯化物）的积累相关。基于有希望的初步研究的结果，该项目的主要研究人员（PIS）建议探索微生物链伸长延伸的耦合，其目的是鉴定厌氧微生物的联盟，以减少和转化PCE/TCE以使用链中的链元素，以实现链式的数量，以便将其用于链元素，以便将其携带数量。为了促进这一目标，PI提议将集成的实验和建模研究计划执行1）1）揭示了控制微生物链延长介导的脱核化的关键代谢途径和生态相互作用，以及2）开发并验证并验证与去催化剂造成的微生物链延长的计算代谢模型。该研究的具体目标是：1）表征有机壁炉呼吸和链链的细菌财团的生长和抑制动力学和代谢网络，该联盟已显示出有望将PCE/TEC转化为乙烯的有希望的潜力，并且2）揭示了与微生物链接的相互作用，并在竞争中互动的替代机器人的相互作用，并且社区。这项研究的成功完成通过产生新的基本知识和计算代谢模型，可以通过微生物链延伸介导的脱催化来推动地下水生物修复的开发和部署。为了实施该项目的教育和培训目标，PIS提议利用各自机构的现有计划将这项研究的发现整合到亚利桑那州立大学的RET（教师研究经验）计划中，并在佛蒙特大学（UVM）的扩展计划（4-H）将教师和学生启发高中教师和学生的使用，以探索Microorororerororerorerorermanismiss的使用。此外，PIS计划在ASU和UVM上利用现有的REU（本科生的研究经验）计划，以招募来自代表性不足的小组的本科生来从事该项目。该奖项反映了NSF的法定任务，并被认为是通过基金会的智力功能和广泛影响的评估来审查CRITERIA的评估，以评估是值得的。