肉源强致腐假单胞菌与大肠杆菌混合菌膜形成和转移规律及转移后的行为研究

肉品腐败变质是肉品安全主要问题。冷鲜肉营养丰富极易腐败，研究发现生产加工接触面的生物菌膜是导致微生物污染的最主要来源。环境中几乎所有生物菌膜都是由多种微生物组成，群落内部复杂的相互作用显著影响着菌膜社会的结构和活性。肉类屠宰加工不同环境条件下，不同粘附力菌株和成膜顺序可能形成不同结构和性质的混合菌膜，转移至肉表面时菌膜脱落-再定植可能导致原混合菌膜特定结构和性质改变，进而可能影响随后的加工贮藏中转移至肉表面的菌膜行为及致腐效应，然而该科学问题尚未阐明。本项目立足肉品污染和腐败，以肉源优势腐败菌假单胞菌和常见污染菌大肠杆菌为对象，拟研究两菌种混合菌膜形成的交互作用、形成过程、在肉表面转移及转移后的菌膜行为与致腐效应，重点拟采用多组学技术揭示菌膜形成机制及基于模型化定量分析混合菌膜转移规律，揭示混合菌膜形成、肉类污染、肉质腐败三者关联机制，为生产加工中腐败微生物控制、保障肉品安全提供科学依据。

Meat spoilage is one of the crucial problems in meat safety. Chilled meat is highly perishable due to its abundance of essential nutrients. Biofilms on contact surfaces in food processing are the main source of microbial contamination. Nearly all biofilms in the environments are composed of multiple species of microorganisms, and the complex interactions within the community significantly influence the architecture and activity of the biofilm society. The mixed biofilm with different structures and properties will be formed by strains with different adhesion, in different formation sequences, under different environmental conditions of meat slaughtering and processing. When transferred to meat surface, separation and re-colonization of biofilms may affect their structures and properties, which may further affect the behavior of biofilm on meat surface and the meat spoilage process during subsequent processing and storage. The scientific question has not yet been clarified. Thus, based on meat contamination and spoilage, this project aims to study two strains, namely Pseudomonas, one meat-borne predominant spoilage bacterium, and Escherichia coli, one common contaminated bacterium in food processing environment. The interaction of the two species in mixed biofilm, transfer to meat surface, and further behavior of biofilm and their spoilage effects will be investigated, in which the mechanism based on multi-omics and the quantitative transfer model of the mixed biofilm formation are emphasis of this project. The correlation mechanism of the mixed biofilm formation, meat contamination, and meat spoilage will be revealed, which will provide scientific basis for the control of meat spoilage microorganisms and the guarantee of meat safety in meat processing.