本文關(guān)鍵詞： 洛克沙胂 S. oneidensis MR-1 生物轉(zhuǎn)化 可溶性Fe(Ⅲ) 含水率　出處：《合肥工業(yè)大學(xué)》2016年碩士論文　論文類(lèi)型：學(xué)位論文

【摘要】：洛克沙胂作為一種廣泛應(yīng)用的畜禽養(yǎng)殖業(yè)飼料添加劑,在動(dòng)物體內(nèi)基本不被降解,會(huì)隨畜禽糞便和養(yǎng)殖廢水進(jìn)入土壤和水環(huán)境中,導(dǎo)致潛在的砷污染。希瓦氏菌是一種兼性厭氧菌,在土壤、海洋和其他水體中廣泛存在,能在厭氧條件下利用多種電子受體,包括三價(jià)鐵、硝酸鹽、亞硝酸鹽和某些重金屬離子等,進(jìn)行產(chǎn)能代謝和電子傳遞。本論文以洛克沙胂為研究對(duì)象,選取模式菌種奧奈達(dá)湖希瓦氏菌(Shewanella oneidensis MR-1)作為處理洛克沙胂的手段,分析土壤含水率條件變化對(duì)洛克沙胂生物轉(zhuǎn)化的影響,探究S. oneidensis MR-1轉(zhuǎn)化洛克沙胂的機(jī)理。主要結(jié)論如下：水相厭氧體系中S. oneidensis MR-1對(duì)洛克沙胂生物轉(zhuǎn)化的可行性：在水相厭氧環(huán)境中,S. oneidensis MR-1可以將洛克沙胂作為最終的電子受體,還原為4-羥基-3-氨基苯胂酸(HAPA),并且HAPA為洛克沙胂生物轉(zhuǎn)化還原后的唯一檢出產(chǎn)物;然而在缺乏外源性底物時(shí),洛克沙胂不能直接被S. oneidensis MR-1轉(zhuǎn)化,證明了短期內(nèi)洛克沙腫無(wú)法充當(dāng)生物轉(zhuǎn)化的可利用的碳源。不同濃度洛克沙腫濃度對(duì)S. oneidensis MR-1轉(zhuǎn)化洛克沙胂的影響實(shí)驗(yàn)表明洛克沙胂不會(huì)抑制S. oneidensis MR-1的生長(zhǎng),反而會(huì)促進(jìn)其生長(zhǎng),起始洛克沙胂濃度越高細(xì)菌生長(zhǎng)速度越快。水相中可溶性Fe(Ⅲ)的存在對(duì)S. oneidensis MR-1生物轉(zhuǎn)化洛克沙胂的影響：在水相厭氧環(huán)境中,S. oneidensis MR-1存在的條件下,可溶性Fe(Ⅲ)的出現(xiàn)能夠顯著的促進(jìn)S. oneidensis MR-1轉(zhuǎn)化洛克沙胂,同時(shí),加入的可溶性Fe(Ⅲ)在反應(yīng)中會(huì)生成次生鐵礦,吸附洛克沙胂轉(zhuǎn)化生成的HAPA,有機(jī)胂得到了固定,降低了砷的遷移性；但是高濃度的可溶性Fe(Ⅲ)不僅不能促進(jìn)S.oneidensis MR-1生物轉(zhuǎn)化洛克沙胂,反而會(huì)抑制S. oneidensis MR-1對(duì)洛克沙胂生物轉(zhuǎn)化；較低濃度的可溶性Fe(Ⅲ)(2.0mmol/L)就足以促進(jìn)S. oneidensis MR-1生物轉(zhuǎn)化洛克沙胂,但是由于加入不同濃度可溶性Fe(Ⅲ)生成的次生鐵礦量不一樣,實(shí)驗(yàn)終止時(shí)4-羥基-3-氨基苯胂酸(HAPA)被吸附的量也相應(yīng)的不同。固相多孔介質(zhì)中不同含水率情形下,S. oneidensis MR-1的胞外聚合物(EPS)分泌量隨著含水率水平減小而增加；含水率的變化明顯影響S. oneidensis MR-1轉(zhuǎn)化洛克沙胂,只有到達(dá)一定含水率水平,足夠達(dá)到提供S. oneidensis MR-1生長(zhǎng)繁殖以及轉(zhuǎn)移電子的水環(huán)境,洛克沙胂才能夠被S. oneidensis MR-1所轉(zhuǎn)化,同時(shí)發(fā)現(xiàn)含水率越高,洛克沙胂被轉(zhuǎn)化的效率越高。
[Abstract]:Roxarsone, as a widely used feed additive for livestock and poultry breeding, is basically not degraded in animals and will enter the soil and water environment with animal manure and wastewater. Shiva is a facultative anaerobes that are widespread in soils, oceans and other water bodies and can use a variety of electron receptors in anaerobic conditions, including iron trivalent, nitrate, and so on. Nitrite and some heavy metal ions were used for capacity metabolism and electron transport. In this paper, the model strain Shewanella oneidensis MR-1 was selected as the treatment method of roxarsone. The effects of soil moisture content on roxarsone biotransformation were analyzed. To explore the mechanism of the transformation of roxarsone by S. oneidensis MR-1. The main conclusions are as follows: the feasibility of the biotransformation of roxarsone by S. Oneidensis MR-1 in aqueous anaerobic system: in aqueous anaerobic environment, roxarsone can be used as the final electron receptor by oneidensis MR-1. The product was reduced to 4-hydroxy-3-aminophenylarsonic acid, and HAPA was the only product detected after bioconversion of roxarsone. However, roxarsone could not be directly transformed by S. oneidensis MR-1 in the absence of exogenous substrates. The results showed that roxarsam could not be used as an available carbon source for biotransformation in a short period of time. The effects of roxarsam concentrations on the transformation of roxarsone by S. oneidensis MR-1 showed that roxarsone did not inhibit the growth of S. oneidensis MR-1, but promoted the growth of roxarsone. The higher the initial roxarsone concentration, the faster the bacterial growth rate. The effect of soluble Fe (鈪，

本文編號(hào)：1494584