21EngBio: Engineering Biology for Molecular Precursor Production

21EngBio：分子前体生产的工程生物学

• 批准号: BB/W013037/1
• 负责人: Lu Shin Wong
• 金额: $ 12.81万
• 依托单位: University of Manchester
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FW013037%2F1
• 关键词: 21EngBio; Engineering; Biology; Molecular; Precursor

Alkoxysilanes are silicon-containing compounds that are used in the production of a huge variety of consumer and industrial products including machine parts, electronic components, adhesives, abrasives and ceramics. For example, a type of ceramic called silicon carbide has received much interest recently as it is used in several high-technology applications. This material can conduct electricity at very high voltages and currents, and hence it is used in the power transmission components of wind turbines and electric vehicles. Its extreme hardness and heat resistance means that it has also found uses in the aerospace industry for rocket nozzles and heat shielding, as well as in personal and vehicular armour plating in the defence and security sector.However, the production of these alkoxysilanes is currently very energy intensive, relatively inefficient and environmentally unfriendly. Specifically, their production employs refined silicon, which is itself produced by the smelting of quartz rock with coal at very high temperatures in a furnace. This silicon is then reacted with chlorine (a very toxic and corrosive gas) and an alcohol to finally produce the desired alkoxysilanes. An additional issue with the current process is that quartz of suitable quality is mainly available in two places on the globe, in Norway and the central USA. It is anticipated that it may be difficult for these sources to meet the growing demand of the manufacturing sector in the coming years. There is therefore a need to develop alternative methods of producing alkoxysilanes that are more eco-friendly and are not reliant on limited quartz reserves. In fact, silicon is an abundant element in nature and is found in most minerals. Many plants also absorb silicon from the soil. Though there have been several attempts in the past 40 years to produce alkoxysilanes directly from these crude minerals or plant matter, they have been hampered by the difficulty in removing unwanted metal contaminants from these raw materials.It has been known for many years that some species of marine sponges incorporate silicon into their skeletons by condensing water soluble forms of silicon that are found in seawater. This process is facilitated by an enzyme termed 'silicatein', which enables the formation of silicon-oxygen chemical bonds under mild biological conditions. Notably, more recent research has shown that the enzyme can be used to produce simple alkoxysilanes under laboratory conditions. This project will expand on these early findings to develop a biologically-inspired route to the production of alkoxysilanes that will be cheap, widely available and environmentally sustainable. Specifically, this project will genetically modify a harmless bacterium so that it produces modified versions of silicatein enzymes that have greater ability to produce industrially relevant alkoxysilanes. The host bacteria will then further genetically modified, so that it presents these enzymes on their surface. In doing so, the bacteria can themselves perform the reaction without needing to extract the enzyme from the bacteria. The work will also focus on the isolation of these alkoxysilanes with a high degree of purity (free from trace metals) by harnessing the enzyme's natural preference for reacting only with silicon. Finally, a process will be developed that combines fermentation of sugars by yeasts to produce alcohol, with the engineered bacteria, so that by only adding crude minerals and sugar, the desired alkoxysilanes can be produced in a single process.By demonstrating how enzymes and bacteria can be used like a chemical factory, this project will demonstrate how biology can be harnessed to address what is essentially an engineering challenge - the improved production of an industrial chemical of high economic value.

烷氧基硅烷是一种含硅化合物，用于生产各种消费品和工业产品，包括机器零件、电子元件、粘合剂、磨料和陶瓷。例如，一种名为碳化硅的陶瓷最近引起了人们的兴趣，因为它被用于多个高科技应用中。这种材料可以在非常高的电压和电流下导电，因此它被用于风力涡轮机和电动汽车的电力传输组件。其极高的硬度和耐热性意味着它还可用于航空航天工业的火箭喷嘴和隔热板，以及国防和安全部门的个人和车辆装甲电镀。然而，目前这些烷氧基硅烷的生产非常耗能，效率相对较低，对环境不友好。具体来说，它们的生产使用精炼硅，而精炼硅本身是通过在熔炉中以非常高的温度将石英石与煤熔炼而产生的。然后，该硅与氯（一种非常有毒和腐蚀性的气体）和醇反应，以最终产生所需的烷氧基硅烷。当前工艺的另一个问题是，合适质量的石英主要在地球仪上的两个地方，即挪威和美国中部可获得。预计这些来源在未来几年可能难以满足制造业日益增长的需求。因此，需要开发生产烷氧基硅烷的替代方法，其更环保并且不依赖于有限的石英储量。事实上，硅是自然界中丰富的元素，存在于大多数矿物中。许多植物也从土壤中吸收硅。尽管在过去的40年中已经有几次尝试直接从这些天然矿物或植物物质生产烷氧基硅烷，但是它们受到难以从这些原料中除去不需要的金属污染物的阻碍。多年来人们已经知道，一些种类的海绵通过冷凝在海水中发现的水溶性形式的硅而将硅结合到它们的骨骼中。这一过程是由一种名为“硅酸盐蛋白”的酶促进的，这种酶能够在温和的生物条件下形成硅氧化学键。值得注意的是，最近的研究表明，该酶可用于在实验室条件下生产简单的烷氧基硅烷。该项目将扩展这些早期发现，以开发一种生物启发的生产烷氧基硅烷的路线，这种路线将是廉价的，广泛可用的和环境可持续的。具体来说，该项目将对一种无害的细菌进行遗传修饰，使其产生经修饰的硅酸盐酶，这些酶具有更强的生产工业相关烷氧基硅烷的能力。然后宿主细菌将进一步进行遗传修饰，以便在其表面呈现这些酶。在这样做时，细菌可以自己进行反应，而不需要从细菌中提取酶。这项工作还将集中在这些烷氧基硅烷的分离与高纯度（不含微量金属）利用酶的天然偏好，只与硅反应。最后，将开发一种将酵母发酵糖生产酒精与工程菌相结合的工艺，这样只需要添加粗矿物质和糖，就可以在一个过程中生产出所需的烷氧基硅烷。通过演示如何像化学工厂一样使用酶和细菌，该项目将展示如何利用生物学来解决本质上是一项工程挑战--提高具有高经济价值的工业化学品的生产。