酸土脂环酸芽孢杆菌（Alicyclobacillus acidoterrestris）芽孢形成及低pH条件下芽孢萌发的蛋

发布时间：2018-04-01 14:07

本文选题：酸土脂环酸芽孢杆菌　切入点：芽孢形成　出处：《河南科技学院》2017年硕士论文

【摘要】：酸土脂环酸芽孢杆菌具有嗜酸耐热的双重生理生化特征,其芽孢具有更强的耐高温高酸特性,当外部条件适宜时迅速萌发并生长繁殖,引起果汁腐败变质,对低pH食品工业的巴氏灭菌工艺提出严峻的挑战,该菌的危害控制已成为食品研究领域普遍关注的问题。芽孢萌发是细菌开启生长繁殖的关键环节,同时失去极端抗性,是其危害控制的重要阶段。本论文研究了不同营养因子对酸土脂环酸芽孢杆菌芽孢形成及pH值对其芽孢萌发的影响,通过芽孢萌发过程中的蛋白组学研究,揭示其芽孢在低pH条件下萌发生长的调控机制,为控制酸土脂环酸芽孢杆菌污染及如何修订低pH食品的巴氏杀菌工艺提供理论依据。主要研究结果如下:1、葡萄糖、酵母浸粉、Mn~(2+)、Mg~(2+)对酸土脂环酸芽孢杆菌的菌体密度和芽孢形成率影响显著,而Ca~(2+)、NH_4~+和K~+的影响不显著,其中过量的Mn~(2+)和Mg~(2+)会抑制酸土脂环酸芽孢杆菌的生长,Ca~(2+)与K~+或者与NH_4~+协同作用时可以促进酸土脂环酸芽孢杆菌芽孢的形成。2、通过芽孢菌悬液光密度检测和环境扫描电镜检测,发现酸土脂环酸芽孢杆菌芽孢萌发的最佳pH值为4.0;在pH 3.0和5.0条件下,芽孢萌发过程延长,pH为2.0时芽孢外壁受到破坏。3、酸土脂环酸芽孢杆菌芽孢在pH 3.0条件下萌发2 h,有98种蛋白差异表达,分子功能主要集中在磷酸三酯活性、乳酰谷胱甘肽裂解酶活性、核糖体的结构组成、分子结构活性、转移酶活性、肽酶活性和外肽酶活性等;生物学过程主要集中在有机氮化合物生物合成和代谢、蛋白代谢、谷氨酰胺代谢、细胞蛋白代谢和有机物合成等中;涉及的通路有beta-内酰胺抗性、核糖体、次级代谢产物合成、丙酮酸代谢、卟啉和叶绿素代谢、萜类化合物骨架合成、双组分系统和细菌分泌系统等。
[Abstract]:Bacillus acidophilus has the double physiological and biochemical characteristics of acidophilic and heat-resistant, and its spores have stronger resistance to high temperature and high acid. When the external conditions are suitable, the spores germinate rapidly and grow and reproduce, causing the fruit juice to decay and metamorphose.The pasteurization technology of low pH food industry is challenged, and the hazard control of this bacterium has become a common concern in the field of food research.The germination of spores is a key step for bacteria to start growth and reproduction. At the same time, the loss of extreme resistance is an important stage of its hazard control.It provides a theoretical basis for controlling the contamination of Bacillus acidoides and how to revise the pasteurization technology of low pH food.The main results were as follows: 1: 1, glucose, yeast extract (MNM) 2) had a significant effect on the cell density and spore formation rate of Bacillus acidoides, but Ca~(2 had no significant effect on NH4 ~ and K ~.Excessive amount of Mn~(2 and Mg~(2 can inhibit the growth of Bacillus acidoacidoides.) in the synergistic action with K ~ or NH _ 4 ~, it can promote the formation of spores of Bacillus acidophilus, and detect the density of Bacillus acidoides suspensions by light density.Environmental scanning electron microscopy,It was found that the optimum pH value for the germination of Bacillus acidophilus was 4.0, and the optimum pH was 3.0 and 5.0, respectively.The outer wall of the spores was destroyed at pH 2.0 during the germination of spores. The spores of Bacillus acidophilus germinated at pH 3.0 for 2 h, and 98 proteins were differentially expressed. The molecular function was mainly concentrated in the activity of triglyceride phosphate.Lactoglutathione lyase activity, ribosome structure, molecular structure activity, transferase activity, peptidase activity and exopeptidase activity, etc. The biological processes mainly focus on the biosynthesis and metabolism of organic nitrogen compounds, protein metabolism, etc.The pathways involved include beta-lactam resistance, ribosome, secondary metabolite synthesis, pyruvate metabolism, porphyrin and chlorophyll metabolism, terpene skeleton synthesis, etc.Two component system and bacterial secretion system, etc.
【学位授予单位】：河南科技学院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TS201.3

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