CAREER: PFAS-BioAction: Innovative treatment of municipal solid waste organics through insect-mediated bioprocessing and sequestration of poly- and perfluoroalkyl substances

食物和有机废物是垃圾填埋场中城市固体废物的最大组成部分。2018年，垃圾填埋场处理的食物和有机废物超过3000万吨。填埋有机废物的管理具有挑战性，因为它通常需要设计和整合处理列车，以控制气味排放和有毒渗滤液以及二氧化碳和甲烷等温室气体的释放。昆虫介导的生物转化（IMB）已成为将食物/有机废物转化为有用产品的一种有前途和可持续的替代方法。IMB的基本前提是，食物/有机废物可以用作种植昆虫的基质，然后这些昆虫可以加工成有价值的产品，包括动物饲料、生物燃料、堆肥或更高价值的土壤改良剂。本职业发展项目的总体目标是探索利用IMB隔离和降解持久性有毒污染物，最初侧重于填埋有机废物中的多氟烷基和全氟烷基物质。为了实现这一目标，首席研究员建议使用黑兵蝇幼虫（BSFL）作为模型系统来研究PFAS在昆虫体内的积累过程以及PFAS在昆虫肠道中被酶降解的程度。该项目的成功完成将通过产生新的基础知识来促进IMB作为一种可持续处理pfas污染的填埋有机废物的技术的发展，从而造福社会。进一步的社会效益将通过学生教育和培训来实现，包括在加州大学戴维斯分校指导一名研究生和一名本科生。昆虫介导的生物转化（IMB）已经成为一种有前途的、可扩展的、具有成本效益的平台，可以从有机废物流中产生有价值的产品。然而，人们对IMB处理和降解持久性有毒污染物（如常存在于填埋有机废物中的PFAS）的潜力知之甚少。本CAREER项目旨在研究黑兵蝇（black soldier fly， BSFL）幼虫对PFAS的生物积累和转化，BSFL是一种具有高脂和高蛋白质含量的有机废物转化潜力的昆虫。本研究的两个主要目标是：1)探索PFAS与模型脂质和蛋白质的相互作用，揭示PFAS在昆虫组织中的生物积累机制；2)评估BSFL对PFAS的生物积累、代谢和生物转化的程度。为了实现这些目标，首席研究员（PI）建议开展一项综合实验和建模研究计划，该计划将1)液相色谱四极杆飞行时间质谱（LC-QTOF-MS）与针对性分析相结合，以评估转移食物垃圾、堆肥和垃圾渗滤液中PFAS的丰度和多样性；2)原子分子动力学（MD）模拟，以人血清白蛋白为模型系统预测PFAS与蛋白质的结合亲和力；3)离体分析，测量PFAS在BSFL组织匀浆中蛋白质和脂质部分的生物积累；4)实验分析，测量和表征PFAS在BSFL组织中的生物积累和生物转化。该项目的成功完成有可能通过产生新的基础知识来推动IMB作为一种高效和具有成本效益的PFAS修复技术的开发和实施，从而产生变革性影响。为了实现这个CAREER项目的教育和培训目标，PI将修改她在加州大学戴维斯分校的一门本科课程，包括一个CURES（基于课程的本科研究经验）模块，该模块将参与三到四名学生组成的团队，通过一个完整的探究周期，从开发一个研究问题和一个与污染物（如PFAS）的生物积累有关的可测试假设开始。此外，PI计划积极与工程教育工作者和专业人士合作，传播教育资源，分享其CAREER项目的主要研究成果，并围绕以科学为基础的解决方案促进有意义的对话，以实现零浪费的未来。该奖项反映了美国国家科学基金会的法定使命，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。

Food and organic wastes are the largest component of municipal solid waste in landfills. In 2018, over 30 million tons of food and organic wastes were disposed of in landfills. The management of landfilled organic wastes is challenging as it often requires the design and integration of treatment trains to control odor emissions and the release of toxic leachates and greenhouse gases such as carbon dioxide and methane. Insect mediated bioconversion (IMB) has emerged as a promising and sustainable alternative to convert food/organic wastes to useful products. The basic premise of IMB is that food/organic wastes can be used as substrates to grow insects which can then be processed into valuable products including animal feed, biofuels, and compost or higher-value soil amendments. The overarching goal of this CAREER project is to explore the use of IMB to sequester and degrade persistent and toxic contaminants with an initial focus on poly- and perfluoroalkyl substances (PFAS) from landfilled organic wastes. To advance this goal, the Principal Investigator proposes to use the black soldier fly larvae (BSFL) as model systems to investigate how PFAS accumulate in insects and the extent of PFAS degradation by enzymes in insect guts. The successful completion of this project will benefit society through the generation of new fundamental knowledge to advance the development of IMB as a sustainable treatment technology for PFAS-contaminated landfilled organic wastes. Further benefits to society will be achieved through student education and training including the mentoring of a graduate student and an undergraduate student at the University of California, Davis.Insect-mediated bioconversion (IMB) has emerged as a promising, scalable, and cost-effective platform to generate valuable products from organic waste streams. However, little is known about the potential of IMB to treat and degrade persistent and toxic contaminants such as PFAS that are often present in landfilled organic wastes. This CAREER project proposes to investigate the bioaccumulation and biotransformation of PFAS by black soldier fly larvae (BSFL), a family of insects with great potential to convert organic wastes to useful products due to their high lipids and protein contents. Two key goals of the research are to: 1) probe PFAS interactions with model lipids and proteins to unravel the mechanisms of PFAS bioaccumulation in insect tissues and 2) evaluate the extents of PFAS bioaccumulation, metabolism, and bioconversion by BSFL. To advance these goals, the Principal Investigator (PI) proposes to carry out an integrated experimental and modeling research program that will combine 1) liquid-chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) with targeted analysis to evaluate the abundance and diversity of PFAS in diverted food waste, finished compost, and landfill leachate, 2) atomistic molecular dynamics (MD) simulations to predict the binding affinities of PFAS to proteins using human serum albumin as model system, 3) ex vivo assays to measure PFAS bioaccumulation in the protein and lipid fractions of BSFL tissue homogenates, and 4) experimental assays to measure and characterize PFAS bioaccumulation and biotransformation in the tissues of BSFL. The successful completion of this project has the potential for transformative impact through the generation of new fundamental knowledge to advance the development and implementation of IMB as an efficient and cost-effective PFAS remediation technology. To implement the educational and training goals of this CAREER project, the PI will revise one of her undergraduate courses at UC-Davis to include a CURES (course-based undergraduate research experiences) module that will engage teams of three to four students through a complete inquiry cycle, beginning with the development of a research question and a testable hypothesis linked to the bioaccumulation of contaminants such as PFAS. In addition, the PI plans to actively engage with engineering educators and professionals to disseminate educational resources, share key research findings from her CAREER project, and promote meaningful dialogue around science-based solutions for achieving a zero-waste future.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.