SusChEM: Engineered protein-based biofilms as functional advanced materials

SusChEM：基于蛋白质的工程生物膜作为功能先进材料

• 批准号: 1410751
• 负责人: Neel Joshi
• 金额: $ 50万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-01 至 2019-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1410751&HistoricalAwards=false
• 关键词: SusChEM; Engineered; protein; based; biofilms

Nontechnical: This SusCheM award by the Biomaterials program in the Division of Materials Research to Harvard University is part of a broad effort to "domesticate" bacterial biofilms for the extraction of rare earth metals and materials. Biofilms are communities of bacterial cells living inside a self-generated biopolymer matrix. This project aims to genetic engineer a non-pathogenic laboratory strain of E. coli to produce altered forms of this biopolymer matrix that have beneficial functions. Specifically, biofilms will be modified the surfaces of proteins with metal binding capabilities. This modification will allow the biofilms to selectively bind to rare earth elements. Rare earths are essential for a variety of cutting edge technologies, including smartphone displays, electric vehicles, and wind turbines. As such, their availability is critical to technological innovation and resource independence in the United States. Despite this, more than 90% of the world's rare earth metals are mined and extracted outside United States because of the lack of environmental and sustainable technologies. The engineered biofilms research proposed aims to develop cheaper, sustainable, green and environment-friendly technologies to extract rare earth metals in USA. Integrated with the research plan will be an intensive student trainings program that will incorporate new teaching initiatives in the fields of biomaterials and bioengineering, and recruiting and mentorship of several graduate and undergraduate students with a focus on women and underrepresented minority students. Undergraduate students will be exposed to STEM topics with a focus on genetic engineering through established internship programs in the Campus. Coordination of outreach activities with local high schools to stimulate interest in STEM education is also part of this project.Technical: The overall goal of this SusCheM project is to develop a platform for genetically engineering bacterial biofilms that can serve as scalable materials with programmable, non-natural functions. With this award, the Principal Investigator will study the genetic modification and characterization of the proteinaceous mesh-like surface coating present in biofilms secreted by bacteria. This proteinaceous surface coating called 'curli' contains structural proteins, which self-assemble into an encapsulating network of amyloid fibers in the biofilm. This research involves genetic fusion of peptide motifs to the 'curli' proteins such that the fused peptides are on the surface of the amyloid fibers in the biofilm. These modified 'curli' proteins will be studied for structural and functional properties with a focus on specific metal binding capabilities. The peptide modified biofilms will be produced, and their ability to form extracellular amyloids networks will be characterized as a function of peptide linker length. A plate-based screening strategy will be used to evaluate the composition and metal binding properties of the engineered biofilms and identify those that can selectively and efficiently enrich rare earth elements. The system will also be integrated in a laboratory scale continuous flow separation apparatus to evaluate its potential in an industrially relevant model. Ultimately, the results of this investigation will facilitate the development of a wide range of biofilm-based materials using renewable sources. The research will be integrated with a cross-disciplinary mentoring plan in which graduate and undergraduate students will be trained in subfields of molecular biology, materials science, and chemical/biological engineering.

非技术性：哈佛大学材料研究部生物材料项目的SusChem奖是“驯化”细菌生物膜以提取稀土金属和材料的广泛努力的一部分。生物膜是生活在自生生物聚合物基质中的细菌细胞群落。本项目的目的是基因工程的非致病性实验室菌株的E。大肠杆菌来产生具有有益功能的这种生物聚合物基质的改变形式。具体而言，生物膜将被修饰具有金属结合能力的蛋白质表面。这种修饰将允许生物膜选择性地与稀土元素结合。稀土对于智能手机显示屏、电动汽车和风力涡轮机等各种尖端技术至关重要。因此，它们的可用性对美国的技术创新和资源独立至关重要。尽管如此，由于缺乏环境和可持续技术，世界上90%以上的稀土金属是在美国以外开采和提取的。美国提出的工程生物膜研究旨在开发廉价、可持续、绿色和环境友好的稀土金属提取技术。与研究计划相结合的将是一个密集的学生培训计划，该计划将纳入生物材料和生物工程领域的新教学计划，并招募和指导几名研究生和本科生，重点是妇女和代表性不足的少数民族学生。本科生将接触到STEM主题，重点是基因工程，通过在校园里建立实习计划。与当地高中协调外展活动以激发对STEM教育的兴趣也是该项目的一部分。技术：该SusChem项目的总体目标是开发一个基因工程细菌生物膜的平台，该生物膜可以作为具有可编程非天然功能的可扩展材料。有了这个奖项，主要研究者将研究细菌分泌的生物膜中存在的蛋白质网状表面涂层的遗传修饰和表征。这种被称为“卷曲”的蛋白质表面涂层含有结构蛋白，它们在生物膜中自组装成淀粉样纤维的封装网络。这项研究涉及肽基序与“卷曲”蛋白的基因融合，使得融合的肽位于生物膜中淀粉样纤维的表面。将研究这些修饰的“curli”蛋白的结构和功能特性，重点是特定的金属结合能力。将产生肽修饰的生物膜，并且它们形成细胞外淀粉样蛋白网络的能力将被表征为肽接头长度的函数。基于板的筛选策略将用于评估工程生物膜的组成和金属结合特性，并确定那些可以选择性和有效地富集稀土元素的生物膜。该系统还将集成在实验室规模的连续流分离装置中，以评估其在工业相关模型中的潜力。最终，这项研究的结果将促进利用可再生资源开发各种基于生物膜的材料。该研究将与跨学科的指导计划相结合，研究生和本科生将在分子生物学，材料科学和化学/生物工程的子领域进行培训。