Grow-Your-Own Composites: Programming Diverse Material Properties for Defence into Engineered Bacterial Cellulose

细菌纤维素是一种强大的、超纯的生物材料纳米纤维素，它是由几种醋酸杆菌细菌（包括雷蒂克氏乳杆菌）自然大量产生的。细菌纤维素生产成本低廉，具有理想的纯度、高结晶度和拉伸性能，并且不像植物纤维素那样含有其他杂质。它是可塑的，具有生物相容性，能够储存超过其总重量90%的水，并且在医疗伤口敷料，高端声学和许多其他不同产品中找到了许多商业应用。在这个提案中，我们计划在我们最近成功的基础上，指导帝国理工学院2014年iGEM团队开发基因操作方法和一个雷蒂库菌的合成生物学工具包，这是第一个高产纤维素细菌的工具包。我们的愿景是使用合成生物学方法来修改从雷提克氏菌中产生的细菌纤维素的生产，使细菌培养物现在产生具有多样化和高度期望的材料特性的可编程纤维素复合材料，理想的国防应用。通过使用我们的合成生物学工具，并将这个工具包扩展为进一步的功能，如基因组编辑和基于光的控制，我们将能够在DNA水平上改变和控制细菌，这样它们现在就可以分泌具有不同体积特性（如改变的疏水性）的改性细菌纤维素。我们还将使用我们的工具包，让我们的生长细菌生产细菌纤维素和其他生物材料，如生物塑料、功能蛋白质（如酶）和蛋白质聚合物（如卷曲纤维和丝绸）的交织混合物。结果将是各种生物合成的纳米纤维素复合材料，可能具有有价值的材料特性，可以提高用这种基质制造的材料的强度和延展性，而不会进一步显著增加重量和成本。结合我们团队在合成生物学、复合材料工程和爆炸研究方面的丰富专业知识，我们将共同开发方法，将这些细菌纤维素复合材料安全地转化为轻质层状复合材料和先进的气凝胶，这些气凝胶与防护和减震等国防应用所需的材料性能相匹配。我们将测试新型生物合成复合材料的机械性能，并以此反馈改进的第二代设计。我们的项目汇集了英国八大技术中的两项——合成生物学和先进材料，并将为使用基于dna的细胞工程来生产具有许多不同和有价值的未来应用的先进生物材料复合材料奠定基础。

Bacterial cellulose is a strong, ultrapure form of the biomaterial nanocellulose, which is naturally made in large amounts by several species of Acetobacter bacteria including K. rhaeticus. Bacterial cellulose is cheap to produce, has desirable purity, high crystallinity and tensile properties and does not contain other impurities like those found in plant cellulose. It is mouldable, biocompatible and capable of storing water over 90% of its total weight, and has found numerous commercial applications in medical wound-dressings, high-end acoustics, and many other diverse products.In this proposal, we plan to build on our recent success guiding the Imperial College 2014 iGEM team in developing genetic manipulation methods and a synthetic biology toolkit for K. rhaeticus, the first toolkit of note for bacteria that produce cellulose in high yields. Our vision is to use synthetic biology methods to modify the production of bacterial cellulose from K. rhaeticus so that the bacterial cultures now produce programmable cellulose composites that have diverse and highly-desired material properties, ideally for defence applications. By using our synthetic biology tools and expanding this toolkit with further features such as genome editing and light-based control, we will be able to alter and control bacteria at the DNA level so that they now can be made to secrete modified bacterial cellulose with different bulk properties such as altered hydrophobicity. We will also use our toolkit to get our growing bacteria to produce interwoven mixtures of bacterial cellulose and other biomaterials such as bioplastics, functional proteins (e.g. enzymes) and protein polymers (e.g. curli fibres and silks). The result will be a variety of biosynthesised nanocellulose composites, likely to have valuable material properties that improve the strength and ductility of materials fabricated with this substrate, without increasing the weight and cost significantly further. Combining our team's considerable expertise in synthetic biology, composite engineering and blast research, we will together develop methods to safely convert these bacterial cellulose composites into lightweight layered composite materials and into advanced aerogels that match the material properties desired for defence applications in protection and shock absorption and more. We will test the mechanical properties of our new biosynthesised composites and use this to feedback to improved second-generation designs. Our project brings together Synthetic Biology and Advanced Materials, two of the UK's Eight Great Technologies, and will lay the foundations for using DNA-based engineering of cells to produce advanced biomaterial composites with many diverse and valuable future applications.