发酵牛肉中金黄色葡萄球菌食物中毒缺失机制研究

发布时间：2019-04-27 18:22

【摘要】：金黄色葡萄球菌食物中毒是一种由于食物污染有产肠毒素金黄色葡萄球菌而引起的毒素型食物中毒。近年国内外学者研究表明，理论上推断的容易造成金黄色葡萄球菌食物中毒的发酵牛肉却存在金黄色葡萄球菌食物中毒缺失现象，本论文对发酵牛肉金黄色葡萄球菌食物中毒机制机制进行探讨，可丰富金黄色葡萄球菌源食物中毒预防理论研究，对于金黄色葡萄球菌源食物中毒预防新技术研究具有重大的实用价值和重要的理论意义。本实验研究按照发酵牛肉传统加工工艺，在发酵牛肉加工原料肉中接种产肠毒素金黄色葡萄球菌(Staphylococcus aureus)和植物乳杆菌(L. plantarum)、戊糖片球菌(P. pentosaceus)组合的复合发酵剂，并以不接种发酵剂的发酵牛肉作为对照，研究发酵牛肉在加工过程以及贮藏阶段金黄色葡萄球菌及其肠毒素的变化规律，分析影响金黄色葡萄球菌及其肠毒素的主要因素，并研究了在培养基条件下发酵剂菌株植物乳杆菌和戊糖片球菌及各种栅栏因子对金黄色葡萄球菌及其肠毒素的影响，对植物乳杆菌和戊糖片球菌抑制金黄色葡萄球菌的机理进行了初步研究。研究结果表明： 1．发酵牛肉加工过程中，自然发酵牛肉中没有金黄色葡萄球菌及其肠毒素；接种发酵剂和金黄色葡萄球菌的发酵牛肉中金黄色葡萄球菌呈现先上升然后快速下降趋势，但金黄色葡萄球菌肠毒素为阴性；接种金黄色葡萄球菌的发酵牛肉中金黄色葡萄球菌及其肠毒素都显著高于接种发酵剂的发酵牛肉（P0.05）。发酵剂植物乳杆菌和戊糖片球菌对金黄色葡萄球菌有很强的抑制作用。 2．发酵牛肉在贮藏阶段，自然发酵牛肉中不含有金黄色葡萄球菌且肠毒素表现为阴性，接种金黄色葡萄球菌的发酵牛肉中金黄色葡萄球菌数量和肠毒素含量呈下降趋势，接种发酵剂和金黄色葡萄球菌的发酵牛肉中金黄色葡萄球菌含量快速降低。 3．在培养基条件下，低温对于金黄色葡萄球菌及其肠毒素有明显的抑制作用，而食盐含量、pH值对金黄色葡萄球菌生长及其肠毒素产生影响不显著。 4．植物乳杆菌和戊糖片球菌对金黄色葡萄球菌有抑制作用，且植物乳杆菌对金黄色葡萄球菌的抑制作用更强。植物乳杆菌和戊糖片球菌的代谢产物中对金黄色葡萄球菌有抑制作用的活性物质主要是有机酸、细菌素和过氧化氢等，均具有良好地热稳定性，，且植物乳杆菌的抑菌活性物质对胰蛋白酶、蛋白酶K不敏感，对胃蛋白酶敏感；戊糖片球菌代谢产物对胰蛋白酶、蛋白酶K、胃蛋白酶均不敏感。
[Abstract]:Staphylococcus aureus food poisoning is a toxic food poisoning caused by food contamination with enterotoxin-producing staphylococcus aureus. In recent years, scholars at home and abroad have shown that there is a lack of staphylococcus aureus food poisoning in fermented beef which is easy to cause staphylococcus aureus food poisoning. In this paper, the mechanism of food poisoning of fermented beef staphylococcus aureus was discussed, which could enrich the theoretical study on prevention of food poisoning caused by Staphylococcus aureus. It is of great practical value and important theoretical significance for the study of new techniques for prevention of food poisoning caused by S. aureus. In this experiment, according to the traditional processing technology of fermented beef, the fermented beef was inoculated with the combined fermentative agent of S.aureus (Staphylococcus aureus) and (P. pentosaceus) of Lactobacillus botanica (L. plantarum), pentose. The changes of staphylococcus aureus and its enterotoxin in fermented beef during processing and storage were studied, and the main factors affecting staphylococcus aureus and its enterotoxin were analyzed. The effects of Lactobacillus plantarum and Streptococcus pentose and various palisade factors on staphylococcus aureus and its enterotoxin were studied under the condition of culture medium. The mechanism of inhibition of Staphylococcus aureus by Lactobacillus botanica and Pectinococcus pentose was studied. The results showed that: 1. There was no staphylococcus aureus and its enterotoxin in naturally fermented beef during the process of fermented beef; Staphylococcus aureus in fermented beef inoculated with starter and staphylococcus aureus first increased and then decreased rapidly, but staphylococcus aureus enterotoxin was negative. Staphylococcus aureus and its enterotoxin in fermented beef inoculated with Staphylococcus aureus were significantly higher than those in fermented beef inoculated with starter (P0.05). The fermentative agents Lactobacillus plantarum and Streptococcus pentose have a strong inhibitory effect on Staphylococcus aureus. 2. When fermented beef was stored, there was no staphylococcus aureus in naturally fermented beef and enterotoxin was negative, but the number of staphylococcus aureus and enterotoxin content in fermented beef inoculated with Staphylococcus aureus showed a decreasing trend. The content of Staphylococcus aureus in fermented beef inoculated with starter and Staphylococcus aureus decreased rapidly. 3. Under medium conditions, low temperature could inhibit staphylococcus aureus and its enterotoxin obviously, but salt content and pH value had no significant effect on the growth and enterotoxin production of Staphylococcus aureus. 4. Lactobacillus plantarum and Streptococcus pentose have inhibitory effect on staphylococcus aureus, and Lactobacillus botanica has stronger inhibitory effect on staphylococcus aureus. Among the metabolites of Lactobacillus plantarum and Streptococcus pentose, the active substances which have inhibitory effect on Staphylococcus aureus are mainly organic acid, bacteriocin and hydrogen peroxide, all of which have good geothermal stability. The antibacterial active substance of Lactobacillus botanica was not sensitive to trypsin and protease K, but sensitive to pepsin. The metabolites of Streptococcus pentose were not sensitive to trypsin, protease K and pepsin.
【学位授予单位】：中国农业科学院
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R155.3

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