Exploiting the polysaccharide breakdown capacity of the human gut microbiome to develop environmentally sustainable dishwashing solutions

利用人类肠道微生物群的多糖分解能力来开发环境可持续的洗碗解决方案

• 批准号: 2896097
• 金额: --
• 依托单位: Newcastle University
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2027
• 资助国家: 英国
• 起止时间: 2027 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2896097
• 关键词: Exploiting; polysaccharide; breakdown; capacity; human

Food stains on dishes are complex mixtures of fat, protein and carbohydrates. Many of the carbohydrates in such stains are plant polysaccharides and removal of these stains often requires high temperature and significant levels of chemical detergents. A potential solution to reducing the energy and detergent requirements for effective stain removal during dishwashing is to use specific carbohydrate-active enzymes (CAZymes) to break these polysaccharides down into more soluble oligosaccharides that can be removed from dishes more easily. One route to discovery of CAZymes with the potential to be useful in dishwashing formulations is to exploit the huge untapped resource of novel plant polysaccharide degrading CAZymes encoded by our gut microbiota.The major nutrient source for the our gut microbiota are polysaccharides from the diet (often called dietary fibre) as these molecules are not broken down by host digestive enzymes. Because of this evolutionary pressure, the number of CAZymes encoded by the gut microbiota to degrade polysaccharides is vast. In this project we aim to exploit the enormous capacity of the gut microbiota to efficiently degrade a wide range of plant polysaccharides to discover novel CAZymes for use in development of more environmentally sustainable dishwashing formulations. Approach:Bacteroides spp are one of the main genera present in the microbiota and are known to be particularly adept at polysaccharide degradation, with many species encoding hundreds of CAZymes to enable them to fully deconstruct a wide range of different polysaccharides. Our approach for enzyme discovery will be to initially screen our in-house human gut Bacteroides library for growth on a range of soluble polysaccharides associated with different problem food stains (e.g., xylans, mannans, glucans; these will be chosen based on P&G priorities). Proteomics will then be used to identify the specific degradative apparatus involved in species that grow well on target polysaccharides, including the exciting possibility of potentially novel CAZyme families identified by distant homology detection and structural modelling using AlphaFold. Initially we will target likely surface endo-acting enzymes as these are the key enzymes involved in the initial rapid breakdown of extracellular target polysaccharides into oligosaccharides. The rapid transit time of the human gut means that CAZymes from the human microbiome have evolved to break these plant polysaccharides down very efficiently. This high activity, coupled to the fact these enzymes are often located in the extracellular milieu and so highly stable and robust in a range of physical conditions, maximises their potential use in dishwashing formulations.Recombinant versions of target enzymes will be characterised using a range of biochemical techniques available in the host lab to determine the activity and specificity of the purified CAZymes and their role in polysaccharide breakdown. CAZymes active against the targets will be tested with model soils provided by P&G. Initially, we will employ miniaturised systems to evaluate potentially useful enzymes and promising candidates will then be scaled up at P&G to full dishwashing cycles to understand the role of mechanical agitation, T-ramps and kinetics on the overall performance.Over the course of the project, novel and interesting enzyme targets will be advanced into structural studies to define the molecular basis for substrate specificity. Overall, the data generated in this project will provide significant insight into the mechanism of polysaccharide degradation by prominent members of the gut microbiota and underpin the development of novel enzyme strategies to increase the sustainability of novel dishwashing products.

餐具上的食物污渍是脂肪、蛋白质和碳水化合物的复杂混合物。此类污渍中的许多碳水化合物是植物多糖，去除这些污渍通常需要高温和大量化学洗涤剂。减少洗碗过程中有效去除污渍所需的能量和洗涤剂的一个潜在解决方案是使用特定的碳水化合物活性酶 (CAZymes) 将这些多糖分解成更易溶解的低聚糖，从而更容易从餐具中去除。发现可用于餐具洗涤配方的 CAZymes 的一种途径是开发由我们的肠道微生物群编码的新型植物多糖降解 CAZymes 的巨大未开发资源。我们肠道微生物群的主要营养来源是来自饮食的多糖（通常称为膳食纤维），因为这些分子不会被宿主消化酶分解。由于这种进化压力，肠道微生物群编码的用于降解多糖的 CAZymes 数量巨大。在这个项目中，我们的目标是利用肠道微生物群的巨大能力来有效降解多种植物多糖，以发现新型 CAZymes，用于开发更环保的餐具洗涤配方。方法：拟杆菌属是微生物群中存在的主要属之一，已知特别擅长多糖降解，许多物种编码数百种 CAZymes，使其能够完全解构各种不同的多糖。我们的酶发现方法将首先筛选我们内部的人类肠道拟杆菌库，以在与不同问题食品污渍相关的一系列可溶性多糖上生长（例如木聚糖、甘露聚糖、葡聚糖；这些将根据宝洁的优先事项进行选择） 。然后，蛋白质组学将用于识别在目标多糖上生长良好的物种所涉及的特定降解装置，包括通过遥远的同源性检测和使用 AlphaFold 的结构建模来识别潜在的新型 CAZyme 家族的令人兴奋的可能性。最初，我们将靶向可能的表面内切作用酶，因为这些酶是细胞外目标多糖最初快速分解为寡糖所涉及的关键酶。人类肠道的快速转运时间意味着来自人类微生物组的 CAZymes 已经进化到能够非常有效地分解这些植物多糖。这种高活性，再加上这些酶通常位于细胞外环境中，并且在一系列物理条件下具有高度稳定性和鲁棒性，最大限度地发挥了它们在洗碗配方中的潜在用途。目标酶的重组版本将使用一系列宿主实验室可利用生化技术来确定纯化的 CAZymes 的活性和特异性及其在多糖分解中的作用。针对目标的 CAZymes 将使用宝洁提供的模型土壤进行测试。最初，我们将采用小型化系统来评估潜在有用的酶，然后在宝洁公司将有前途的候选酶扩大到整个洗碗周期，以了解机械搅拌、T 形斜坡和动力学对整体性能的作用。在项目过程中新颖而有趣的酶靶标将被推进结构研究，以确定底物特异性的分子基础。总体而言，该项目生成的数据将为肠道微生物群的重要成员降解多糖的机制提供重要的见解，并支持新型酶策略的开发，以提高新型洗碗产品的可持续性。