發(fā)布時(shí)間：2018-04-28 22:32

  本文選題：木葡糖酸醋桿菌 + 細(xì)菌纖維素　； 參考：《天津科技大學(xué)》2017年碩士論文

【摘要】：近年來(lái),由于細(xì)菌纖維素所具有的高純度,高親水性、高生物相容性以及良好的機(jī)械性能被廣泛應(yīng)用于生物醫(yī)藥行業(yè),造紙行業(yè)以及食品等行業(yè)。木葡糖酸醋桿菌Gluconacetobacter xyinus作為細(xì)菌纖維素的模式生產(chǎn)菌株,其生產(chǎn)細(xì)菌纖維素的確切機(jī)制尚不明確。本實(shí)驗(yàn)室之前已證實(shí)在G.xylinus CGMCC 2955中存在類(lèi)似費(fèi)氏弧菌的LuxI/LuxR型群體感應(yīng)系統(tǒng)。大量文獻(xiàn)表明群體感應(yīng)與生物膜的合成有密切的關(guān)系,此本文針對(duì)群體感應(yīng)與細(xì)菌纖維素合成之間的相關(guān)性進(jìn)行了探究。首先利用分子生物學(xué)手段構(gòu)建群體感應(yīng)關(guān)鍵基因luxR過(guò)表達(dá)載體,將其電轉(zhuǎn)化到G.xylinus,通過(guò)靜置培養(yǎng)和振蕩培養(yǎng)兩種培養(yǎng)方式來(lái)比較原始菌株與過(guò)表達(dá)菌株發(fā)酵性能的差異,并比較細(xì)菌纖維素的結(jié)構(gòu)性能差異。結(jié)果發(fā)現(xiàn),在振蕩培養(yǎng)條件下,與G.x相比,G.x-pMV24-luxR的菌體生長(zhǎng)速度明顯減緩,到發(fā)酵結(jié)束,菌體量降低15.51%,葡萄糖酸的產(chǎn)量提高了 12.11%,對(duì)葡萄糖酸的利用率提高了 20.18%,但二者總酸產(chǎn)量無(wú)明顯差異。在靜置條件下,與G.x相比,G.x-pMV24-luxR的纖維素產(chǎn)量提高了 36.45%,且在16d葡萄糖酸含量降低了23.68%。對(duì)比各菌株所產(chǎn)的細(xì)菌纖維素的性能,傅里葉紅外光譜(Fourier Transform infrared spectroscopy, FT-IR)分析由于差異均存在于非結(jié)晶區(qū),表明細(xì)菌纖維素內(nèi)官能團(tuán)結(jié)構(gòu)沒(méi)有明顯差異;X射線衍射(X-ray diffraction.,XRD)表明G.x-pMV24-luxR產(chǎn)的纖維素結(jié)晶度明顯降低;TG/DTG表明G.x-pMV24-luxR產(chǎn)纖維素的熱穩(wěn)定性降低。利用代謝組學(xué)方法,對(duì)G.x以及G.x-pMV24-luxR胞內(nèi)小分子代謝物的的差異進(jìn)行分析,探究群體感應(yīng)對(duì)胞內(nèi)代謝的影響。結(jié)果表明luxR過(guò)表達(dá)對(duì)中心代謝、氨基酸代謝、脂代謝均有影響。G.x-pMV24-luxR大量合成葡萄糖酸,并且對(duì)嘌呤嘧啶的從頭合成也具有促進(jìn)作用,但是卻抑制了氨基酸代謝和脂代謝,海藻糖作為一種細(xì)胞保護(hù)性物質(zhì),在葡萄糖酸大量合成的同時(shí)其含量也明顯增加。
[Abstract]:In recent years, bacterial cellulose has been widely used in biomedical industry, paper industry and food industry because of its high purity, high hydrophilicity, high biocompatibility and good mechanical properties. As a model strain of bacterial cellulose production, the exact mechanism of the production of bacterial cellulose by Gluconacetobacter xyinus is unclear. It has been previously confirmed in our laboratory that there is a LuxI/LuxR type population sensing system in G.xylinus CGMCC 2955 similar to Vibrio flexneri. A large number of literatures have shown that there is a close relationship between population induction and biosynthesis of biofilm. The correlation between group induction and bacterial cellulose synthesis is explored in this paper. Firstly, the overexpression vector of luxR gene was constructed by molecular biology, and transformed into G. xylinus. The fermentation performance of the original strain was compared with that of the overexpression strain by static culture and oscillatory culture. The structure and properties of bacterial cellulose were compared. The results showed that the growth rate of G. x-pMV24-luxR was significantly slower than that of G.x under oscillatory culture conditions, and the growth rate of G. x-pMV24-luxR was significantly slower than that of G.x, until the end of fermentation. The yield of gluconic acid and the utilization rate of gluconic acid were increased by 15.51 and 12.11 respectively, but there was no significant difference between them. Under static conditions, the cellulose yield of G.x-pMV24-luxR increased by 36.45, and the gluconic acid content decreased by 23.68% at 16 days compared with G. x. Comparing the properties of bacterial cellulose produced by each strain, Fourier Transform infrared spectroscopy (FT-IRI) analysis showed that the differences existed in the amorphous region. The results showed that there was no obvious difference in the structure of functional groups in bacterial cellulose. X-ray diffraction (XRD) showed that the crystallinity of cellulose produced by G.x-pMV24-luxR was obviously decreased. The results showed that the thermal stability of cellulose produced by G.x-pMV24-luxR was lower than that of TG / DTG. In order to explore the effect of population induction on intracellular metabolism, the differences between G. x and G.x-pMV24-luxR small molecule metabolites were analyzed by means of metabonomics. The results showed that the overexpression of luxR had an effect on the metabolism of central, amino acid and lipid. G.x-pMV24-luxR also promoted the ab initio synthesis of purine pyrimidine, but inhibited the metabolism of amino acid and lipid. Trehalose, as a cytoprotective substance, increases the content of gluconic acid in a large amount at the same time.
【學(xué)位授予單位】：天津科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類(lèi)號(hào)】：Q78;O636.11

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 湯衛(wèi)華;賈士儒;賈原媛;殷海松;;納米生物材料細(xì)菌纖維素在醫(yī)學(xué)領(lǐng)域的應(yīng)用研究[J];生物醫(yī)學(xué)工程學(xué)雜志;2014年04期

2 柯朝甫;張濤;武曉巖;李康;;代謝組學(xué)數(shù)據(jù)分析的統(tǒng)計(jì)學(xué)方法[J];中國(guó)衛(wèi)生統(tǒng)計(jì);2014年02期

3 汪麗粉;李政;賈士儒;張健飛;;細(xì)菌纖維素性質(zhì)及應(yīng)用的研究進(jìn)展[J];微生物學(xué)通報(bào);2014年08期

4 賈士儒;劉淼;薄濤;;細(xì)菌纖維素的研究及其應(yīng)用[J];山東輕工業(yè)學(xué)院學(xué)報(bào)(自然科學(xué)版);2013年03期

5 湯衛(wèi)華;賈士儒;王們;殷海松;;細(xì)菌纖維素在造紙工業(yè)中的應(yīng)用[J];中國(guó)造紙學(xué)報(bào);2013年01期

6 劉琳;譚小娟;賈愛(ài)群;;細(xì)菌群體感應(yīng)與細(xì)菌生物被膜形成之間的關(guān)系[J];微生物學(xué)報(bào);2012年03期

7 張艷軍;張曉云;李志敏;葉勤;;腺嘌呤對(duì)大腸桿菌DH5_α和其耐乙酸突變株DA19代謝流分布的影響[J];微生物學(xué)報(bào);2011年10期

8 鄭世超;羅瑛;魯濤;;LuxR家族調(diào)控蛋白的結(jié)構(gòu)及功能[J];生命科學(xué);2010年09期

9 阿基業(yè);;代謝組學(xué)數(shù)據(jù)處理方法——主成分分析[J];中國(guó)臨床藥理學(xué)與治療學(xué);2010年05期

10 譚玉靜;洪楓;邵志宇;;細(xì)菌纖維素在生物醫(yī)學(xué)材料中的應(yīng)用[J];中國(guó)生物工程雜志;2007年04期

相關(guān)博士學(xué)位論文 前1條

1 馬霞;發(fā)酵生產(chǎn)細(xì)菌纖維素及其作為醫(yī)學(xué)材料的應(yīng)用研究[D];天津科技大學(xué);2004年

相關(guān)碩士學(xué)位論文 前5條

1 蔣高鵬;基于細(xì)菌纖維素的質(zhì)子交換膜的制備、表征及其在燃料電池中的應(yīng)用研究[D];東華大學(xué);2012年

2 徐千;細(xì)菌纖維素纖維在造紙工業(yè)中的應(yīng)用[D];天津科技大學(xué);2010年

3 李靜;細(xì)菌纖維素的制備及結(jié)構(gòu)與性能研究[D];青島大學(xué);2008年

4 隋曉鋒;結(jié)構(gòu)可控纖維素功能材料的制備和性能研究[D];清華大學(xué);2008年

5 潘穎;細(xì)菌纖維素的制備及改性研究[D];青島大學(xué);2007年

，

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