Developing novel phage-based techniques for removing spoilage bacteria from meat products

真空包装（VP）的肉在开封后会有一种难闻的气味，这是由肉表面腐败细菌的活动产生的。这些细菌不会致病，在烹饪时也无害，但消费者可能会认为肉类变质了，从而丢弃产品，导致食物浪费过多，并因与劣质肉类联系在一起而对品牌产生负面影响。克洛基实验室此前曾将英国的一种乳酸菌与肉类腐败联系起来；这些是肉类表面的标准污染物，由于肉类加工程序的限制，在包装前对肉类进行化学清洗是不可行的选择。噬菌体被认为适合于去除恶臭细菌，并鉴定出一些用于腐败细菌的噬菌体。此外，美国食品和药物管理局将噬菌体列为安全的；市场上已经有几种用于食品加工的商业噬菌体产品。由于它们的“安全状态”，噬菌体可以用于肉类产品，以减少不良气味的产生。先前的研究发现，噬菌体成功杀死细菌会改变微生物组的组成，从而减少与异味相关的挥发性化合物的丰度。研究还表明，在不同的氧浓度下，噬菌体与细菌的相互作用不同。这个新项目将继续以前的工作。除了通过与英国主要肉类生产商合作获得宝贵的工业经验外，我们的目标是：建立一个噬菌体库，感染各种产生气味的细菌；评估噬菌体在VP/冷藏条件下的功效；结合噬菌体设计一种鸡尾酒，有效杀死目标细菌；利用转录组学和代谢组学方法鉴定噬菌体代谢体；证明噬菌体鸡尾酒的应用减少了与异味相关的挥发性化合物的产生

When unsealed, vacuum-packed (VP) meat can have an unpleasant odour, produced by the activity of spoilage bacteria on the surface of the meat. These bacteria are not pathogenic, and harmless when cooked, butconsumers may assume the meat is spoiled and discard the product, leading to excess food waste and a negative impact on the brand due to the association with poor quality meat.The Clokie laboratory has previously linked species of lactic acid bacteria to meat spoilage in the UK; these are standard contaminants of the surface ofmeat and with restrictions on meat processing procedures, chemical cleaning of the meat before packaging is not a viable option.Bacteriophages are seen as suitable for removing malodorous bacteria and identified some phages for spoilage bacteria. In addition, the US Food and Drug Administration has classified phages as being safe; several commercial phage products for food processing are already available on the market. Due to their 'safe status', phages could be used on meat products to reduce the production of bad odours.Previous work has found that successful killing of bacteria by phages alters the microbiome composition, in turn reducing the abundance of volatile compounds associated with off odours. It has also been shown that phage interact differently with bacteria under different Oxygen concentrations.The new project will follow on from previous work. In addition to gaining valuable industrial experience by working alongside a major UK meat producer, we aim to undertake the following objectives:Build a library of phages that infect various odour producing bacteriaAssess the efficacy of phages under VP/cold storage conditionsCombine phages to design a cocktail that efficiently kills target bacteriaUse transcriptomic and metabolomic approaches to identify phage metabolomesDemonstrate that the application of the phage cocktail reduces the production of volatile compounds associated with off-odours