When food goes bad: understanding biofilm formation to prevent food spoilage

世界上近10%的人口没有足够的食物。由于预计到2050年全球人口将增至98亿，我们需要将粮食供应水平提高至少50%，才能养活世界人口。一个建议的解决方案是减少粮食损失和浪费，因为据估计，全世界生产的供人类消费的粮食总量中约有三分之一是损失或浪费的。FLW的一个主要贡献者是微生物的腐败。鉴于这些巨大的数字，许多政府和全球组织正在采取多管齐下的方法，以确保我们能够在未来几十年养活世界。事实上，了解导致食品腐败的生物过程的重要性福尔斯BBSRC的战略挑战“3.2.1可持续农业和食品的生物科学”和“减少食物链中的浪费”的响应模式优先事项。微生物（细菌、病毒和真菌）在食物表面或食物链表面生长，形成一层称为生物膜的粘糊糊的膜。生物膜随处可见，从浴室水槽、淋浴和冰箱上形成的黏糊糊的沉积物，到池塘或自然界岩石上看到的黏糊糊的东西。这种粘糊糊的涂层起到了保护层的作用，使得当微生物处于生物膜中时很难杀死它们，并且一旦生物膜形成，就很难物理地去除它。导致一系列肉类、乳制品和蔬菜产品腐败的主要细菌群被广泛称为假单胞菌属。当冰箱里的食物变质并被你扔掉时，很可能是因为这些细菌在变质的沙拉叶、肉或变质牛奶中的聚集物上的生物膜中生长。在英国，平均每个成年人损失或浪费了280公斤食物，这导致了大约100万人死亡。6.7仅在英国，每年就有152，000辆满载卡车的食物被浪费。目前还没有直接针对食品表面生物膜形成的策略来延长食品的保质期或阻止食品腐败。总的来说，本奖学金的工作旨在：1。确定我们是否可以通过靶向生物膜粘滞部分的共同成分，细胞外DNA（eDNA），来阻止假单胞菌在食物上形成生物膜。许多细菌在生物膜粘液中有eDNA，这为生物膜提供了强度和结构，并帮助生物膜抵抗去除它的尝试。我有一种叫做NucB的酶，它可以分解eDNA。在这项工作中，我将测试将NucB放在食物表面是否会阻止细菌形成生物膜，以及我是否可以用NucB去除食物上已经形成的生物膜。2.了解假单胞菌如何在食物上的生物膜中生长，导致食物腐败。通过详细了解这一过程，我们将能够开发新的方法来阻止食品或食物链表面（例如食品加工厂或食品包装）上形成生物膜，以延长保质期并减少食品腐败。这项工作可以直接转化为解决方案，以减少食物上细菌的生长，从而减少食物腐败。此外，本奖学金中开发的技术将非常有助于了解其他细菌，例如那些导致食物中毒的细菌，是如何通过食物链传播的。

Almost 10% of the world's population do not get enough to eat. Since the global population is predicted to rise to 9.8 billion by 2050, we need to increase levels of food availability by at least 50% to be able to feed the world's population. One proposed solution has been to reduce food loss and wastage (FLW), since it is estimated that around 1/3 of the total food produced for human consumption worldwide is either lost or wasted. A major contributor to FLW is spoilage by microbes. Given these drastic numbers, many governments and global organisations are adopting a multi-pronged approach to ensure we can feed the world over the coming decades. Indeed, the importance of understanding biological processes that lead to food spoilage falls within the BBSRC's Strategic Challenge '3.2.1 Bioscience for Sustainable Agriculture and Food' and the Responsive Mode Priority of 'Reducing Waste in the Food Chain'.Microbes (bacteria, viruses and fungi) grow on the surfaces of food, or on surfaces in the food chain, in a slimy film called a biofilm. Biofilms are found everywhere, from the slimy deposits that form on the bathroom sink, shower and fridge, to the slime seen in ponds or on rocks in nature. The slimy coating acts as a protective layer, making it very difficult to kill microbes when they are in biofilms and to physically remove the biofilm once it has formed. A major group of bacteria that cause spoilage of a range of meat, dairy and vegetable products are broadly called Pseudomonas species. When food in your fridge goes off and you throw it out, it is very likely to be due to these bacteria growing in biofilms on spoiled salad leaves, meat or on the aggregates in spoiled milk. On average 280 kg of food is lost or wasted per adult in the UK, which contributes to approx. 6.7 million tonnes, or 152,000 full lorries, of food wasted each year in the UK alone. There are currently no strategies that directly target biofilm formation on food surfaces to either extend the shelf life of food or stop food spoilage. Overall, the work in this Fellowship aims to: 1. Determine if we can stop Pseudomonas species forming biofilms on food by targeting a common component of the slimy part of biofilms, extracellular DNA (eDNA). Many bacteria have eDNA in the biofilm slime, which provides strength and structure to the biofilm and helps the biofilm resist attempts to remove it. My preliminary data shows that there is eDNA in Pseudomonas species biofilms. I have access to an enzyme called NucB, which can break down eDNA. In this work I will test if putting NucB on food surfaces stops bacteria forming biofilms and if I can remove a biofilm that is already formed on food with NucB. 2. Understand how Pseudomonas species grow in biofilms on food to bring about food spoilage. By understanding this process in detail, we will then be able to develop new ways to stop biofilms forming on food, or on surfaces in the food chain (e.g. in food processing plants or on food packaging) to extend the shelf-life and reduce food spoilage. This work could be directly translated into solutions to reduce the growth of bacteria on food and thus food spoilage. Additionally, the techniques developed in this Fellowship will be very useful in understanding how other bacteria, for instance those that cause food poisoning, are transmitted through the food chain.