Analyses of interactions and potential functions of microbiota in beef meat for maintaining food safety and quality

Beef is one of the most consumed food in the world, and it can be spoilage or occurred foodborne illness by microbes. These risks could be caused by resident microbiota and their interactions in beef meat. However, there are little information about the potential risk factors by resident microbiota and interactions between microbes in beef meat. In this study, we analyzed the composition, bacterial interactions, and their predicted functions of microbiota in beef meat. A total of 120 beef meat samples (60 fresh ground and 60 non-grounded beef samples) were collected from three different sites and different sampling months in South Korea, and the microbiota were analyzed by the MiSeq system. Although the microbiota in beef meat were different in each sampling site and sampling month, the dominant phyla were same with sharing core bacteria. In particular, psychrotrophic genera related to spoilage were detected in all samples, and they were significantly increased in July. In the co-occurrence networks, genera related to spoilage were negatively correlated to other indigenous genera. These genera could inhibit the growth of other microbes with using glucose by fermentation. Carnobacterium could play the key role in these interactions. Results in this study extend our understanding of microbiota and spoilage by resident microbiota in beef meat, and can apply to develop the prevention and reduction the bacterial risks of beef meat products.

牛肉是全球消费量最高的食品之一，其可因微生物作用发生腐败或引发食源性疾病（foodborne illness）。这类风险多由牛肉中的驻留微生物群（resident microbiota）及其相互作用所导致。然而，目前关于牛肉中驻留微生物群带来的潜在风险因素，以及牛肉内微生物间相互作用的相关信息仍较为匮乏。
本研究针对牛肉中的微生物群组成、细菌相互作用及其预测功能展开分析。研究团队从韩国三个不同采样地点、不同采样月份中共收集了120份牛肉样本（60份新鲜绞碎牛肉与60份非绞碎牛肉样本），并通过MiSeq系统（MiSeq system）对微生物群进行测序分析。
尽管不同采样地点与采样月份下的牛肉微生物群存在差异，但所有样本的优势菌门保持一致，且共享核心细菌类群。尤为值得注意的是，所有样本中均检出与腐败相关的嗜冷菌属，且该类菌属在7月份的相对丰度显著升高。
在共现网络（co-occurrence networks）分析中，与腐败相关的菌属与其他本土菌属呈负相关关系。这类菌属可通过发酵利用葡萄糖，从而抑制其他微生物的生长。其中，肉杆菌属（Carnobacterium）在这些相互作用中可能发挥关键作用。
本研究结果加深了我们对牛肉驻留微生物群及其介导的腐败现象的认知，可为牛肉制品细菌风险的防控与消减技术研发提供理论支撑。