沙门氏菌噬菌体聚集介导的抗菌蛋白膜形成及其释放抑菌机制研究

抗菌活性蛋白膜不仅可持续地抑制微生物生长繁殖，还能有效地阻控交叉污染的发生，是食品活性包装领域重要的发展方向。本项目在前期研究分离获得的一株沙门氏菌烈性噬菌体的基础上，通过噬菌体全基因组测序，解析其主要结构蛋白氨基酸序列、两亲性、疏水性和电荷电位等，探明其作为生物大分子维持活性稳定的分子基础；以成膜蛋白为基材，制备噬菌体抗菌蛋白膜，利用界面技术比较研究噬菌体与成膜蛋白溶液微观膜和宏观膜的界面性能，表征噬菌体聚集及其与成膜蛋白分子相互作用的成膜规律，优化膜的制备体系；进一步探讨抗菌蛋白膜中噬菌体在液-液、液-固界面的释放扩散动力学及其分子机制，评价其对冷鲜鸡肉污染沙门氏菌的抑菌效果。预期研究结果可为开发新型噬菌体类食品抗菌剂提供新的思路，为研制特异性强、抑菌性好的噬菌体抗菌蛋白膜提供理论依据。

Active packaging materials with antimicrobial properties have gained significant interest over the last decade. Currently, most of the antimicrobial active packaging materials are broad spectrum antimicrobials which do not target bacterial pathogenic species specifically. The need for specificity in antimicrobial activity is important as pathogens may be a small fraction of the total microbial load present in food systems. Thus, developing pathogen specific antimicrobial active packaging materials may improve the antimicrobial efficacy by reducing interactions with non-targeted microbes. Bacteriophages are viruses of bacteria that have high specificity for their host strain and multiply upon infecting their host for up to 1000 viral progeny per bacteria. Based on these advantages and increases in antimicrobial resistance among common pathogens, phage can have significant applications as additives to packaging material formulations. A bacteriophage against Salmonella enteritidis has been isolated and characterized, this study will complete the whole genome sequencing and analyze the molecular structures of main structural proteins of the bacteriophage strain, such as the molecule, charge, amphiphilic, hydrophobic and helix. Then, we will develop a subclass of bacteriophage encapsulated protein films, and characterize its antimicrobial efficacy, stability and release of encapsulated phages. The formation mechanism of antimicrobial protein films encapsulated phages will be clarified at molecular level after thoroughly examining the relationship between the micro-film formed on interface of protein solution and the macro-film coated. Additionally, the phages release from protein films will be studied in an aqueous environment and food surface incubation. Furthermore, the antimicrobial efficacy will be evaluated for fresh chicken coated by the active packaging materials. This study will demonstrate integration of phages with edible packaging materials to develop novel active packaging materials for biocontrol applications.