Chemical Mapping of Chromate Uptake, Localization, and Reduction in Remediating B

修复 B 中铬酸盐吸收、定位和还原的化学图谱

基本信息

批准号：
7995998
负责人：
Joseph MK Irudayaraj
金额：
$ 30.08万
依托单位：
PURDUE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-01-08 至 2014-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7995998
关键词：
Address Bacteria Bioavailable Biochemical Biochemistry Biological Biological Models Biology Bioreactors Bioremediations Catalysis Cell Culture Techniques Cell Survival Cell membrane Cell surface Cells Chemicals Chromates Chromium Complex Cytoplasm Cytosol Development Distal Drug Metabolic Detoxication Engineering Enhancers Environment Environmental Impact Environmental Pollution Environmental Risk Factor Enzymes Event Fluorescence Generations Gold Growth Hazardous Waste Sites Health Heavy Metals Human ICP-AES Image Imaging Techniques Immobilization In Situ In Vitro Investigation Ions Knowledge Laboratories Life Link Maps Measurement Measures Mediating Metabolic Metals Methodology Microbe Microscopy Molecular Monitor Nanostructures National Institute of Environmental Health Sciences Nutrient Organism Outcome Oxidoreductase Performance Polyethylene Glycols Population Powder Diffraction Process Proteobacteria Resolution Roentgen Rays Scheme Shapes Shewanella Signal Transduction Silver Site Soil Source Structure Sulfhydryl Compounds Surface Testing Toxic effect United States United States National Institutes of Health Variant Work appendage base carcinogenicity cell growth chromium hexavalent ion cost effective improved in vivo microbial microorganism nanoparticle nanoprobe nanorod nanoscale nanowire novel particle periplasm pollutant remediation respiratory response success uptake

项目摘要

DESCRIPTION (provided by applicant): Cr(VI) contamination of soil and groundwater is a significant problem worldwide. In the United States, chromate is the third most common contaminant of hazardous waste sites and the second most common inorganic contaminant found in the environment. In situ and ex situ bioremediation processes that exploit the intrinsic metabolic capabilities of dissimilatory metal ion-reducing bacteria (DMRB) remain potent, potentially cost-effective approaches to the reductive immobilization or detoxification of environmental contaminants. The microbial catalysis of Cr(VI) reduction to sparingly soluble, less bioavailable Cr(III), for example, is a promising remediation strategy for Cr(VI)-contaminated subsurface soil and groundwater environments. The genus Shewanella represents one of the few groups of microorganisms that have received intensive investigation because of their wide ecological distribution, diverse respiratory capacities, and environmental relevance. Despite several advances made in elucidating Shewanella biology as it relates to chromate transformation, fundamental questions about the specific chromate reduction mechanism remain unclear. This information gap includes (i) the identity of dedicated chromate reductase(s), (ii) the cellular localization of chromate transformation (e.g., distal appendages, outer cell surface, periplasm, cytoplasmic membrane, cytosol), and (iii) the environmental parameters under which microbial populations have the greatest specific chromate reduction rates. The problem in predicting and assessing bioremediation performance is compounded by the lack of fundamental knowledge of the molecular basis, regulatory mechanisms, and biochemistry enabling bacterial metal-reducing capabilities. We propose to engineer nanoscale methodologies, comprising of chromate-tagged nanoparticles and intracellularly grown gold nanoislands to function as enhancers for Surface Enhanced resonance Raman scattering probing to generate chemical maps of chromate reduction sites as well as to monitor the reduction dynamics in exquisite molecular and single-organism detail. Objectives of this study are to 1) assess the impact of gold nanoparticle composition, geometry, and functionality on cell viability, growth, and efficacy of microbial chromate reduction using S. oneidensis as a model system; 2) track the localization of chromate transformation at single-cell resolution using functionalized gold nanostructures as well as using intracellularly grown gold nanoislands by Raman chemical imaging; and 3) evaluate the influence of bioremediation-relevant environmental factors on chromate transport, localization, and reduction rates. The development of passive and active nanoprobes in conjunction with confocal Raman chemical imaging will constitute a significant step in enabling a platform for dynamic monitoring of intracellular events and compartmentalization of metal reduction sites at single-cell resolution. The knowledge gained from this novel study will contribute to the development of scientifically grounded strategies for improving bioremediation efficacy.

描述（由申请人提供）：在全球范围内，土壤和地下水的CR（VI）污染是一个重大问题。在美国，铬酸盐是危险废物站点的第三大最常见污染物，也是在环境中发现的第二大常见的无机污染物。原位和原位生物修复过程，这些过程利用了脱离金属离子还原细菌（DMRB）的内在代谢能力（DMRB）仍然有效的，潜在的具有成本效益的方法来减少环境污染物的还原或排毒。例如，CR（VI）还原至少量可溶性，较少生物利用CR（III）的微生物催化是一种有希望的CR（VI）污染地下土壤和地下水环境的有希望的补救策略。 Shewanella属代表了少数几个微生物之一，这些微生物因其广泛的生态分布，多样化的呼吸能力和环境相关性而接受了深入研究。尽管阐明Shewanella生物学方面取得了一些进展，这与铬酸盐的转化有关，但有关特定铬酸盐还原机制的基本问题仍不清楚。此信息差距包括（i）专用铬酸盐还原酶（s），（ii）彩色酸盐转化的细胞定位（例如，远端附属物，外部细胞表面，周面，细胞质膜，细胞质），（iii）和（iii）在哪些微生物种群下具有最大的特定于Chromate Chromate reduction的环境参数。缺乏对分子基础，调节机制和生物化学的基本知识，可以使细菌金属还原能力的基本知识，调节机制和生物化学缺乏基本知识。我们建议设计纳米级方法，包括铬酸盐标记的纳米颗粒和细胞内生长的金纳米群岛，以充当表面增强共振拉曼散射探测的增强剂，以产生彩色降低站点的化学图，以监测精美的单一形成细节的减少动力学。这项研究的目标是1）评估金纳米颗粒组成，几何和功能对使用S. oneidensis作为模型系统的微生物铬酸盐降低的细胞活力，生长和功效的影响； 2）使用功能化的金纳米结构在单细胞分辨率下跟踪铬酸盐转化的定位，并通过拉曼化学成像使用细胞内生长的金纳米岛； 3）评估与生物修复有关的环境因素对铬酸盐运输，定位和降低率的影响。被动和活性纳米探针与共焦拉曼化学成像结合的发展将构成一个重要的一步，以使能够在单细胞分辨率下动态监测细胞内事件的平台和金属还原位点的分室化。从这项新研究中获得的知识将有助于发展基于生物修复功效的科学基础策略。