CAS:Scalable platform for materials fabrication from genetically engineered bacterial biomass

非技术概述：本项目的目的是研究从细菌生物膜中提取的蛋白质作为一种新型生物聚合物用于生物塑料生产。尽管传统塑料对全球温室气体排放有重大贡献，但由于缺乏生物降解性而造成环境破坏，因此迫切需要替代传统塑料的替代品，预计其产量将会增加。尽管存在一些可生物降解的生物塑料，但它们缺乏作为大多数传统塑料替代品所需的物理性能，因为它们是由有限的一组自然产生的生物聚合物制成的。一种有吸引力的解决方案利用合成生物学领域的最新进展，利用工程微生物创造出全新的生物聚合物。在之前NSF资助的资助下，研究人员开发了一种使用工程非致病性大肠杆菌生产可定制蛋白质聚合物的方法。这项技术使蛋白质聚合物的分子结构能够被定制成表现出所需的一组性质，类似于可以使用合成化学来定制传统聚合物的结构的方式。对于这个项目，他们将进一步研究使用这个平台来生产具有增强材料性能的生物塑料。他们的方法将涉及三个目标：1)设计蛋白质聚合物本身的结构，以使其更坚韧；2)对产生蛋白质聚合物的微生物进行工程，以使其产量最大化；以及3)从微生物生物质中制造生物塑料，并对其特性进行表征。这项工作的结果将有助于推动国家生物制造能力的界限，帮助它们转向更可持续的模式，以应对气候变化和塑料污染的迫在眉睫的挑战。该技术研究计划与一项计划相结合，该计划将在面向大学生的课程工作中引入与生物制造相关的新兴主题，使他们能够通过动手培训和创造性的问题解决来推进生物系统工程。技术摘要：这项建议描述了一种整合的研究和教学努力，将推动生物材料和生物制造技术的前沿，并包括对理工科学生进行多种技能水平的培训。这项拟议的研究解决了对具有增强材料性能的可生物降解生物塑料的迫切需求。传统塑料是我们水道和垃圾填埋场的主要污染源，它们的制造对全球温室气体排放有很大贡献。微生物衍生的可生物降解生物塑料是解决这些问题的一种有吸引力的方法，因为它们可以通过发酵扩大生产，并且可以依赖可再生原料。然而，现有的微生物衍生生物塑料的制造方法完全依赖于一组有限的自然产生的生物聚合物，这些聚合物表现出次优的材料性能，需要繁琐的纯化和下游加工才能发挥作用。该项目研究使用能够生产蛋白质聚合物的工程微生物，其结构可以通过基因工程进行调整，作为生产具有增强材料性能的可生物降解生物塑料的手段。以类似于使用合成化学来创建具有针对特定应用高度定制的结构的石油衍生聚合物的方式，该项目将使用合成生物学来创建具有可调特性的新的生物聚合物。该项目的重点是研究这种新的生物制造方法的互补方面：1)改造由大肠杆菌生产的重组蛋白质纤维，以显示更高的机械稳定性；2)改造大肠杆菌底盘，以最大限度地生产这些蛋白质纤维；以及3)开发利用整个微生物生物量的方案，以便以适合大规模生产的方式简化生物塑料制造过程。这项工作将推进蛋白质工程、代谢工程和生物材料科学的基础研究，以推进其目标。该提案还将把生物材料和生物制造理论和实践的基本方面纳入东北大学将要开发的新课程中，并在东北大学重新建立一个iGEM团队。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Non-technical summary:The purpose of this project is to investigate the use of proteins derived from bacterial biofilms as a new class of biopolymers for bioplastics production. There is an urgent need for alternatives to conventional plastics, whose manufacture is projected to increase, despite its significant contributions to global greenhouse gas emissions, and the environmental damage caused by its lack of biodegradability. Although a few biodegradable bioplastics exist, they lack the required physical properties to be suitable as replacements for most conventional plastics because they are made from a limited set of naturally occurring biopolymers. An attractive solution leverages recent advances in the field of synthetic biology to create entirely new biopolymers using engineered microbes. With a previous NSF-funded grant, the investigators developed a method to produce customizable protein polymers using engineered non-pathogenic E. coli. This technology enables the molecular structure of the protein polymers to be tailored to exhibit a desired set of properties, analogous to the way that synthetic chemistry can be used to tailor the structures of conventional polymers. For this project, they will further investigate the use of this platform for the production of bioplastics with enhanced material properties. Their approach will involve three aims: 1) engineering the structures of the protein polymers themselves, in order to make them tougher; 2) engineering the microbes that produce the protein polymers to maximize the amount that they produce; and, 3) fabricating bioplastics from the microbial biomass and characterizing their properties. The results from this work will help push the boundaries of national biomanufacturing capabilities, helping shift them toward more sustainable paradigms that will address the imminent challenges of climate change and plastic pollution. The technical research plan is integrated with a plan to introduce emerging topics related to biomanufacturing in coursework targeted toward university students and enable them to advance the engineering of biological systems with hands-on training and creative problem solving.Technical summary:This proposal describes an integrated research and teaching effort that will push the frontiers of biomaterials and biomanufacturing technologies and encompass the training of science and engineering students at multiple skill levels. The proposed research addresses an urgent need for biodegradable bioplastics with enhanced material properties. Conventional plastics are a major source of pollution in our waterways and landfills, and their manufacture contributes significantly to global greenhouse gas emissions. Microbially derived biodegradable bioplastics are an attractive way to address these problems because they are amenable to scaled-up production via fermentation and can rely on renewable feedstocks. However, existing methods for making microbially derived bioplastics rely exclusively on a limited set of naturally occurring biopolymers that exhibit sub-optimal material properties and require cumbersome purification and downstream processing in order to be functional. This project investigates the use of engineered microbes capable of producing protein polymers, whose structure can be tuned through genetic engineering, as a means for producing biodegradable bioplastics with enhanced material properties. In a manner that is analogous to the use of synthetic chemistry to create petroleum-derived polymers with structures highly tailored for specific applications, this project will use synthetic biology to create new biopolymers with tunable properties. The project aims focus on investigating complementary aspects of this new biomanufacturing approach: 1) engineering recombinant protein fibers produced by E. coli to exhibit increased mechanical robustness, 2) engineering the E. coli chassis to maximize the production of these protein fibers; and, 3) developing protocols that make use of whole microbial biomass in order to streamline the bioplastic fabrication process in a manner that is suitable for scaled-up manufacturing. The work will advance fundamental research in protein engineering, metabolic engineering, and biomaterials science to advance its aims. The proposal will also incorporate foundational aspects of biomaterials and biomanufacturing theory and practice into new coursework to be developed at Northeastern University (NEU), and the re-establishment of an iGEM team at NEU.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.