氟对小鼠肠道优势菌生长特性的影响

发布时间：2019-03-20 21:45

【摘要】：[目的]研究氟化钠对小鼠肠道大肠杆菌、乳酸杆菌和双歧杆菌生长情况、糖代谢酶和蛋白表达的影响。[方法]以小鼠肠道分离培养的大肠杆菌、乳酸杆菌和双歧杆菌为试验菌株,在培养液中依次加入氟化钠,使其浓度达到0.1mmol/L、1mmol/L、10mmol/L、 100mmol/L,振荡培养。利用比浊法检测大肠杆菌、乳酸杆菌和双歧杆菌的生长情况,采用酸度计检测细菌的产酸情况。利用酶活性检测试剂盒测定糖代谢关键酶的活性。提取大肠杆菌、乳酸杆菌和双歧杆菌总蛋白,采用SDS-PAGE分析细菌蛋白的表达变化。[结果]1.在培养24h内,低浓度氟化钠(0.1mmol/L、1mmol/L)对大肠杆菌的生长有一定的促进作用,同时抑制产酸、增加大肠杆菌的产气;高浓度的氟化钠(100mmol/L)对大肠杆菌的生长有明显的抑制作用,同时明显地抑制产酸、减少大肠杆菌的产气。在培养48h内,低浓度氟化钠(0.1mmol/L)对乳酸杆菌的生长、产酸无明显促进作用,对双歧杆菌的生长、产酸有促进作用；高浓度氟化钠(100mmol/L)对乳酸杆菌和双歧杆菌的生长、产酸有明显抑制作用。2.氟化钠浓度为10mmol/L时,大肠杆菌糖酵解代谢过程的己糖激酶、丙酮酸激酶、琥珀酸脱氢酶和柠檬酸合酶的酶活值明显偏低；氟化钠浓度为1mmol/L时,乳酸杆菌和双歧杆菌的己糖激酶、丙酮酸激酶和乳酸脱氢酶的酶活值明显偏低。3.氟化钠浓度为10mmol/L作用18h,大肠杆菌蛋白浓度为0.33mg/mL,150kDa和25kDa处的蛋白表达上调,45kDa和31kDa处的蛋白表达下调。氟化钠浓度为1mmol/L作用36h,乳酸杆菌蛋白浓度为1.78mg/mL,250kDa、132kDa和75kDa处的蛋白表达上调,92kDa,47kDa和31kDa处的蛋白表达下调。氟化钠浓度为1mmol/L作用36h,双歧杆菌蛋白浓度1.69mg/mL,219kDa、75kDa和28kDa处的蛋白表达上调,62kDa、47kDa和31kDa处的蛋白表达下调。[结论]低浓度氟化钠可促进大肠杆菌的生长和产气,但抑制其产酸,同时会促进双歧杆菌的生长和产酸,但对乳酸杆菌的生长、产酸无明显作用；高浓度氟化钠可抑制大肠杆菌、乳酸杆菌和双歧杆菌的生长和产酸,同时会抑制大肠杆菌的产气。氟化钠浓度为10mmol/L时,即可抑制大肠杆菌某些糖代谢酶的活性；氟化钠浓度为1mmol/L时,即可抑制乳酸杆菌和双歧杆菌某些糖代谢酶的活性。氟化钠会影响大肠杆菌、乳酸杆菌和双歧杆菌蛋白的表达。
[Abstract]:[objective] to study the effects of sodium fluoride on the growth of Escherichia coli, Lactobacillus and bifidobacterium in mice and the expression of glucose metabolizing enzymes and proteins. [methods] Escherichia coli, Lactobacillus and bifidobacterium isolated from the intestinal tract of mice were used as test strains. Sodium fluoride was added into the culture medium in turn, and the concentration was 0.1 mmol / L, 1 mmol / L, 10 mmol / L, 100 mmol / L, respectively. The growth of Escherichia coli, Lactobacillus and bifidobacterium was detected by turbidimetric method, and the acid production of bacteria was detected by acidometer. Enzyme activity test kit was used to determine the activity of key enzymes in glucose metabolism. Total proteins of Escherichia coli, Lactobacillus and Bifidobacterium were extracted and analyzed by SDS-PAGE. [result] 1. Within 24 hours, low concentration of sodium fluoride (0.1 mmol / L, 1 mmol / L) promoted the growth of Escherichia coli, inhibited the acid production and increased the gas production of E. coli. High concentration of sodium fluoride (100mmol/L) can obviously inhibit the growth of Escherichia coli, at the same time, it can obviously inhibit the production of acid and reduce the gas production of E. coli. In 48 h, low concentration of sodium fluoride (0.1mmol/L) did not promote the growth of Lactobacillus and acid production, but promoted the growth and acid production of Bifidobacterium. High concentration of sodium fluoride (100mmol/L) significantly inhibited the growth and acid production of Lactobacillus and Bifidobacterium. The enzyme activities of hexokinase, pyruvate kinase, succinate dehydrogenase and citrate synthase in the glycolytic process of Escherichia coli were significantly lower when the concentration of sodium fluoride was 10mmol/L. The enzyme activities of hexokinase, pyruvate kinase and lactate dehydrogenase of Lactobacillus and Bifidobacterium were significantly lower when the concentration of sodium fluoride was 1mmol/L. When the concentration of sodium fluoride was 10mmol/L for 18 h, the protein concentration of E. coli was 0.33 mg / mL, the protein expression at 150kDa and 25kDa was up-regulated, and the protein expression at 45kDa and 31kDa was down-regulated. After exposure to sodium fluoride for 36 hours, the protein concentration of Lactobacillus was 1.78 mg / mL, 250 kDaa, 132 kDa and 75kDa was up-regulated, while the protein expression at 92 KD, 47 kDa and 31kDa was down-regulated. At the concentration of 1mmol/L for 36 h, the protein concentration of Bifidobacterium was 1.69 mg / mL, the protein expression at 219 KD, 75kDa and 28kDa was up-regulated, while the protein expression at 62kDa, 47kDa and 31kDa was down-regulated. [conclusion] Sodium fluoride at low concentration can promote the growth and gas production of Escherichia coli, but inhibit its acid production, and promote the growth and acid production of Bifidobacterium, but has no obvious effect on the growth of Lactobacillus. High concentration of sodium fluoride can inhibit the growth and acid production of Escherichia coli, Lactobacillus and bifidobacterium, and inhibit the gas production of Escherichia coli. When the concentration of sodium fluoride is 10mmol/L, the activities of some glucose metabolizing enzymes of Escherichia coli can be inhibited, and the activities of some glucose metabolizing enzymes of Lactobacillus and Bifidobacterium can be inhibited when the concentration of sodium fluoride is 1mmol/L. Sodium fluoride affects the expression of E. coli, Lactobacillus and bifidobacterium proteins.
【学位授予单位】：山西农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S852.6

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