Engineering the Physico-Chemical Environment to Enhance the Bioremediation of Developmental Toxicants in Sediment Fungal-Bacterial Biofilms

设计物理化学环境以增强沉积物真菌-细菌生物膜中发育毒物的生物修复

• 批准号: 9256999
• 负责人: Claudia Kneller Gunsch
• 金额: $ 21.6万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/9256999
• 关键词: Amendment; Aromatic Polycyclic Hydrocarbons; Ascomycota; Attention; Bacteria; Beds; Bioavailable; Biodegradation; Biological Availability; Biological Models; Bioremediations; Cells; Characteristics; Chemicals; Chlorophenols; Coculture Techniques; Communities; Cyprinodontidae; Data; Degradation Pathway; Development; Ecosystem; Engineering; Environment; Environmental Exposure; Enzymes; Excision; Exposure to; Fishes; Food Chain; Funding; Fundulus heteroclitus; Growth; Hazardous Waste Sites; Health; Heterogeneity; Hydrophobicity; Immobilization; In Situ; Indigenous; Long-Term Effects; Measures; Mediating; Metabolic; Metagenomics; Metals; Microbial Biofilms; Modeling; Mono-S; Outcome; Parents; Pentachlorophenol; Polychlorinated Biphenyls; Production; Research; Risk; Site; Superfund; Surface; Taxonomy; Testing; Toxic effect; Toxicology; United States; Universities; Water; Work; alternative treatment; base; bioaccumulation; design; exposed human population; extracellular; fungus; innovation; microbial; microbial community; microbiome; microorganism; network models; organic contaminant; receptor; remediation; superfund site; toxicant; trait

Developmental toxicants including polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and chlorophenols (e.g., pentachlorophenol - PCP) are persistent organic contaminants found at many hazardous waste sites throughout the United States. These contaminants are of great concern because they present high toxicological risk in terms of their potential for bioaccumulation in the food chain as well as adverse health effects. Hydrophobic organic contaminants (HOCs) such as PAHs, PCBs and PCP are particularly challenging to bioremediate because their chemical characteristics diminish their bioavailability to microorganisms thereby limiting their potential for efficient biodegradation. As a result of this constraint, HOC remediation strategies tend to focus on physical-chemical approaches consisting of either complete excavation of contaminated media or contaminant in situ immobilization via amendment mediated sequestration which can have significant negative long term impacts on local ecosystems. In this project, we propose an alternative treatment approach which consists of stimulating cooperative bacterial-fungal biofilms for HOC biodegradation. Using this approach, indigenous fungi will first be stimulated to degrade toxicants using nonspecific extracellular enzymes and generate by-products more bioavailable to bacteria for subsequent biodegradation. While using remediation treatment approaches based on the production of fungal extracellular enzymes is not entirely new, the novelty of this project resides in the fact that our focus will be directed towards the promotion of indigenous Ascomycetes associated with sediment microbial biofilms, a phylum which has not received much attention for bioremediation. The overall objective of this project is to maximize HOC biodegradation in sediment settings by stimulating the growth of synergistic fungal-bacterial biofilms using engineered composite organic amendments. The general hypothesis for Project 5 is that the physico-chemical environment can be altered using composite organic amendments to stimulate the formation of a cooperative bacterial-fungal biofilms in which indigenous fungi produce extracellular enzymes breaking down hydrophobic contaminants into by-products which are more readily transported into bacterial cells and broken down by indigenous bacteria. The specific aims for this project are to: 1) Perform microbial and geochemical characterizations of contaminated sediments for the construction of a microbial association network model; 2) Identify organic amendments which support the growth of cooperative fungal-bacterial biofilm and maximize HOC degradation in microcosms; 3) Engineer and test composite amendments for delivery in sediment treatment scenarios and; 4) Implement the composite amendment strategy in large-scale mesocosms as well as validate its efficiency for HOC degradation by stimulated mixed fungal-bacterial biofilms. Ultimately, this project will create a framework to better understand cooperative fungal-bacterial biofilms in the context of sediment bioremediation and yield field translatable approaches for the bioremediation of HOCs.

发育毒物，包括多环芳烃、多氯联苯 和氯苯酚（例如，五氯苯酚（PCP）是一种持久性有机污染物， 美国各地的危险废物处理场。这些污染物非常令人担忧，因为它们 就其在食物链中的生物累积潜力而言， 健康影响。疏水性有机污染物（HOCs），如多环芳烃、多氯联苯和五氯苯酚， 生物修复具有挑战性，因为它们的化学特性降低了其生物利用度， 微生物，从而限制了它们有效生物降解的潜力。由于这一限制，HOC 修复策略往往侧重于物理化学方法，包括完全挖掘， 污染介质或污染物通过改良介导的螯合原位固定， 对当地生态系统有长期的负面影响。在这个项目中，我们提出了一个替代方案， 处理方法，包括刺激合作的细菌-真菌生物膜HOC生物降解。 使用这种方法，土著真菌将首先受到刺激，利用非特异性细胞外降解有毒物质 酶，并产生更多的生物可利用的副产品，细菌随后的生物降解。同时使用 基于真菌胞外酶的产生的补救处理方法并不是全新的， 这一项目的新奇之处在于，我们的重点将是促进土著人民， 与沉积物微生物生物膜相关的子囊菌，一个没有受到太多关注的门， 生物修复该项目的总体目标是通过以下方式最大限度地提高沉积物环境中HOC的生物降解能力： 使用工程复合有机改良剂刺激协同真菌-细菌生物膜的生长。 项目5的一般假设是，物理化学环境可以改变， 复合有机改良剂刺激细菌-真菌协同生物膜的形成， 这种原生真菌产生胞外酶， 这些副产物更容易被转运到细菌细胞中，并被土著细菌分解。 细菌该项目的具体目标是：1）进行微生物和地球化学表征， 污染沉积物中微生物的关联网络模型的构建; 2）识别有机 支持协同真菌-细菌生物膜生长并最大化HOC降解的改良剂 3）设计和测试用于沉积物处理方案的复合修正物; 4)在大规模围隔生态系统中实施复合修正策略，并验证其有效性 通过刺激的混合真菌-细菌生物膜降解HOC。最终，这个项目将创建一个框架， 更好地了解沉积物生物修复和产量背景下的协同真菌-细菌生物膜 用于HOCs生物修复的现场可翻译方法。