本文選題：汞 + 乳酸菌　； 參考：《東北農(nóng)業(yè)大學(xué)》2017年碩士論文

【摘要】：重金屬污染由于其不可生物降解性、危險(xiǎn)性和毒害性不僅使環(huán)境受到破壞,更威脅到了人類和動(dòng)物的公共健康。汞是機(jī)體內(nèi)一種非必需的重金屬元素,可以通過(guò)食物鏈積累,大大增加機(jī)體受到損害的風(fēng)險(xiǎn)。本研究旨在分離、篩選耐汞益生乳酸菌,完善乳酸菌解重金屬中毒的機(jī)理,同時(shí)為解汞中毒提供一個(gè)新的思路及理論基礎(chǔ),為將來(lái)乳酸菌作為生物制劑或者動(dòng)物飼料中的添加劑打下基礎(chǔ)。本試驗(yàn)從健康動(dòng)物腸道內(nèi)容物中分離出有耐汞特性的乳酸菌,對(duì)分離出的菌株進(jìn)行鑒定及益生試驗(yàn)進(jìn)行篩選,挑選出具有優(yōu)良耐汞性能的益生菌株,篩選抗性基因,隨后進(jìn)行動(dòng)物試驗(yàn),通過(guò)抗氧化應(yīng)激、細(xì)胞因子的檢測(cè)及p38 MAPK和NF-κB通路的表達(dá)來(lái)探究篩選的益生乳酸菌解重金屬汞中毒的機(jī)理。主要研究結(jié)果如下:(1)從健康的豬、馬、牛、羊、犬和雞腸道內(nèi)容物中共分離出83株耐汞(25mg/L)菌株,經(jīng)觸酶試驗(yàn)、革蘭氏染色、耐酸、耐膽鹽試驗(yàn)共篩選出21株觸酶試驗(yàn)陰性、耐強(qiáng)酸(pH=2)、耐高濃度膽鹽(0.8%)的革蘭氏陽(yáng)性菌。(2)經(jīng)抑菌試驗(yàn)、藥敏試驗(yàn)、體外抗氧化試驗(yàn)及汞離子吸附能力測(cè)定篩選出4株能夠?qū)ξ宸N致病菌標(biāo)準(zhǔn)菌株有抑制作用、對(duì)抗生素普遍敏感、有較優(yōu)良體外抗氧化能力且在體外對(duì)汞離子吸附能力在90%以上的優(yōu)勢(shì)菌株。(3)經(jīng)分子生物學(xué)鑒定,四株菌株分別為兩株短乳桿菌(Lactobacillus brevis)、一株嗜淀粉乳桿菌(Lactobacillus amylovorus)、一株約氏乳桿菌(Lactobacillus johnsonii)。(4)對(duì)4株乳酸菌進(jìn)行汞及其他重金屬M(fèi)IC測(cè)定,結(jié)果顯示菌株耐汞能力在50~58 mg/L,同時(shí)對(duì)硒、鎘和鎳都有不同程度的耐受能力。(5)綜合體外各項(xiàng)指標(biāo)的結(jié)果,選出最優(yōu)菌株23017進(jìn)行抗性基因的篩選,結(jié)果顯示抗性基因開(kāi)放閱讀框區(qū)域與乳酸菌水通道蛋白Aqy1基因相似度為96%~100%,證實(shí)為水通道蛋白Aqy1基因。(6)測(cè)定小鼠的半數(shù)致死量為52.69mg/kg,建立急性汞中毒小鼠模型,采用篩選出的最優(yōu)勢(shì)菌株短乳桿菌23017進(jìn)行益生菌緩解金屬汞中毒的動(dòng)物試驗(yàn),有如下結(jié)果:a急性汞中毒可使小鼠體重大幅度減輕,短乳桿菌23017可以有效減緩體重下降;b通過(guò)病理切片顯示短乳桿菌23017可有效緩解急性汞中毒引起的機(jī)體肝臟、腎臟以及腸道的損傷;c急性汞中毒后可以在肝臟、腎臟部位形成蓄積,部分可通過(guò)糞便排出體外,短乳桿菌23017可加速汞的排出,減少肝臟和腎臟的負(fù)擔(dān);d短乳桿菌23017可加速急性汞中毒后引起的體內(nèi)氧化-抗氧化系統(tǒng)平衡的恢復(fù);e短乳桿菌23017可使急性汞中毒引起的促炎、抑炎因子以及緊密結(jié)合蛋白的調(diào)控失衡得到緩解。f急性汞中毒可以使p38 MAPK通路和NF-κB通路激活,短乳桿菌23017可以調(diào)節(jié)相關(guān)細(xì)胞因子及蛋白表達(dá)以緩解炎性通路帶來(lái)的損傷。
[Abstract]:Heavy metal pollution not only destroys the environment, but also threatens the public health of human and animals because of its non-biodegradability. Mercury is a non-essential heavy metal element in the body, which can accumulate through the food chain and greatly increase the risk of damage to the body. The purpose of this study was to isolate and screen mercury-tolerant probiotic lactic acid bacteria, improve the mechanism of heavy metal poisoning by lactic acid bacteria, and provide a new way of thinking and theoretical basis for mercury poisoning. To lay a foundation for the future of lactic acid bacteria as biological agents or animal feed additives. In this study, mercury tolerant lactic acid bacteria were isolated from intestinal contents of healthy animals. The strains were identified and prebiotic tests were carried out to select probiotic strains with excellent mercury tolerance and to screen resistant genes. Then animal experiments were conducted to explore the mechanism of heavy metal mercury poisoning by screening probiotic lactic acid bacteria through antioxidant stress cytokine detection and the expression of p38 MAPK and NF- 魏 B pathways. The main results were as follows: (1) A total of 83 strains of mercury-resistant 25 mg / L mercury-resistant strains were isolated from healthy pig, horse, cattle, sheep, dog and chicken intestinal contents. A total of 21 strains were screened negative by thixozyme test, Gram staining, acid tolerance and bile salt tolerance test. Through bacteriostatic test, drug sensitivity test, antioxidant test in vitro and mercury ion adsorption ability test, 4 strains were selected to inhibit five pathogenic bacteria standard strains, which were resistant to strong acid and high concentration of bile salt (0.8% gallbladder salt), and 4 strains were screened out by antimicrobial test, drug sensitivity test, in vitro antioxidant test and mercury ion adsorption ability test. The dominant strain, which is generally sensitive to antibiotics, has excellent antioxidant capacity in vitro and adsorbs more than 90% mercury ions in vitro, has been identified by molecular biology. Four strains of Lactobacillus brevisvisus, Lactobacillus amylovorusus and Lactobacillus johnsoniii.f.) were tested for mercury and other heavy metals MIC. The results showed that the mercury tolerance of the strain was 5058 mg / L, and that of selenium. Cadmium and nickel have different degrees of tolerance. 5) combined with the results of in vitro indicators, the optimal strain 23017 was selected for screening resistance genes. The results showed that the similarity between the open reading frame region of resistance gene and the Aqy1 gene of Lactobacillus aquaporin (Aqy1) gene was 96,100, and the median lethal dose was 52.69 mg / kg. The animal experiment of alleviating mercury poisoning by probiotics was carried out with the most dominant strain of Lactobacillus brevis 23017. The results showed that the weight of mice could be greatly reduced by the acute mercury poisoning of 1: a. Lactobacillus brevis 23017 can effectively slow down weight loss. Pathological sections show that Lactobacillus brevis 23017 can effectively relieve acute mercury poisoning in the liver, kidney and intestine after acute mercury poisoning. The kidney accumulates, partly through feces, and Lactobacillus breast-23017 accelerates the release of mercury. Reducing the burden on the liver and kidney by Lactobacillus brevis 23017 can accelerate the recovery of the balance of oxidation-antioxidant system in vivo caused by acute mercury poisoning. Lactobacillus brevis 23017 can promote inflammation caused by acute mercury poisoning, The imbalance of anti-inflammatory factor and tight binding protein was alleviated. F acute mercury poisoning could activate p38 MAPK pathway and NF- 魏 B pathway. Lactobacillus brevis 23017 could regulate the expression of related cytokines and proteins to alleviate the injury caused by inflammatory pathway.
【學(xué)位授予單位】：東北農(nóng)業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：S816.7

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 ;汞污染下水俁病夢(mèng)魘60年[J];世界環(huán)境;2016年04期

2 劉宇;李陽(yáng);劉通;岳山;周金玲;趙靜虎;王華欣;史同瑞;朱戰(zhàn)波;;乳酸菌益生特性及在豬生產(chǎn)中應(yīng)用研究進(jìn)展[J];動(dòng)物醫(yī)學(xué)進(jìn)展;2016年06期

3 王婭;李平;吳永貴;;萬(wàn)山汞礦區(qū)大米汞污染及人體甲基汞暴露風(fēng)險(xiǎn)[J];生態(tài)學(xué)雜志;2015年05期

4 申云帥;胡建安;;鎘、鉛、汞、砷和鉻致腎損傷機(jī)制的研究進(jìn)展[J];中國(guó)藥理學(xué)與毒理學(xué)雜志;2013年04期

5 錢(qián)春香;王明明;許燕波;;土壤重金屬污染現(xiàn)狀及微生物修復(fù)技術(shù)研究進(jìn)展[J];東南大學(xué)學(xué)報(bào)(自然科學(xué)版);2013年03期

6 孫陽(yáng)昭;陳揚(yáng);劉俐媛;方莉;;從水俁病事件透視日本汞污染防治管理的嬗變[J];環(huán)境保護(hù);2013年09期

7 覃震暉;劉麗萍;;職業(yè)性慢性汞中毒致神經(jīng)系統(tǒng)損害的臨床特點(diǎn)[J];河北醫(yī)學(xué);2012年01期

8 顧兵;張政;李玉萍;余日躍;王心如;;半數(shù)致死量及其計(jì)算方法概述[J];中國(guó)職業(yè)醫(yī)學(xué);2009年06期

9 覃東立;姜秋俚;付友生;;全球汞污染回顧與分析[J];環(huán)境保護(hù)科學(xué);2009年04期

10 胡月紅;;國(guó)內(nèi)外汞污染分布狀況研究綜述[J];環(huán)境保護(hù)科學(xué);2008年01期

相關(guān)碩士學(xué)位論文 前3條

1 夏爽;動(dòng)物腸道源抗鉛益生乳酸菌的分離、鑒定及其緩解鉛毒性的機(jī)理研究[D];東北農(nóng)業(yè)大學(xué);2016年

2 蘇雯;金屬汞對(duì)視覺(jué)系統(tǒng)危害的毒理學(xué)研究[D];中南大學(xué);2012年

3 陳施羽;小白鼠腸道菌群中乳酸菌的篩選及其抗衰老作用初探[D];四川師范大學(xué);2007年

，

本文編號(hào)：1984164