【摘要】：由于人們持續(xù)使用和排放抗生素,天然水環(huán)境中頻繁檢出抗生素類污染物。藍(lán)藻具有原核細(xì)胞結(jié)構(gòu),對(duì)抗生素的敏感程度很高。因此,除了氮、磷等常規(guī)的水環(huán)境因子,抗生素也可能成為調(diào)控藍(lán)藻水華發(fā)生的新興環(huán)境因子。本論文選擇分布廣泛的藍(lán)藻水華模式種銅綠微囊藻為目標(biāo)藻種,選擇水環(huán)境中廣泛檢出的典型抗生素阿莫西林為目標(biāo)抗生素,研究阿莫西林在現(xiàn)有污染水平下對(duì)銅綠微囊藻生長(zhǎng)、產(chǎn)毒和多種生理功能的調(diào)控效應(yīng),通過(guò)半連續(xù)培養(yǎng)試驗(yàn)驗(yàn)證上述調(diào)控效應(yīng)的長(zhǎng)期性,并利用蛋白質(zhì)組學(xué)手段深入探討作用機(jī)制。阿莫西林的暴露濃度為100 ng/L和300 ng/L時(shí),短期暴露條件下銅綠微囊藻葉綠素a含量與對(duì)照組相比顯著增加(p0.05),且與光合作用相關(guān)的基因psbA、psaB和rbcL的表達(dá)量也都明顯上調(diào)。指示光合作用活性的指標(biāo)(Fv/Fm和rETRmax)在阿莫西林長(zhǎng)期暴露條件下也呈現(xiàn)上升趨勢(shì)。蛋白質(zhì)組學(xué)分析結(jié)果進(jìn)一步顯示,psbA、psaB和rbcL基因編碼的蛋白也發(fā)生上調(diào)表達(dá)。上述結(jié)果表明,無(wú)論是短期還是長(zhǎng)期暴露,阿莫西林在環(huán)境濃度下均可以提高銅綠微囊藻的光合作用活性。光合作用受到刺激會(huì)增加能量合成,進(jìn)而導(dǎo)致藻細(xì)胞的生長(zhǎng)速率和微囊藻毒素的產(chǎn)量上升。這可能與低濃度阿莫西林對(duì)藻細(xì)胞的毒物興奮效應(yīng)相關(guān)。顯著性富集的蛋白質(zhì)功能模塊顯示,微囊藻毒素合成酶(mcyB)、泛應(yīng)激蛋白(MAE_48380)和光合作用相關(guān)蛋白之間具有顯著的相互作用(p0.05),這一結(jié)果進(jìn)一步證明了 MCs合成、細(xì)胞應(yīng)激和光合作用之間有密切關(guān)系。在低濃度阿莫西林暴露條件下,藻細(xì)胞的超氧化物歧化酶(SOD)、過(guò)氧化物酶(POD)和谷胱甘肽-S-轉(zhuǎn)移酶(GST)的活性顯著提高(p0.05),抗氧化劑谷胱甘肽(GSH)的含量也顯著增加(p0.05),表明阿莫西林對(duì)藻細(xì)胞產(chǎn)生了氧化壓力,并引發(fā)抗氧化系統(tǒng)應(yīng)激反應(yīng)。蛋白質(zhì)組學(xué)分析進(jìn)一步證明了上述結(jié)果。SOD的表達(dá)量上調(diào),以及phaseⅠ蛋白(硫氧還蛋白過(guò)氧化物酶MAE_35830)和3個(gè)phase Ⅱ蛋白(谷胱甘肽-S-轉(zhuǎn)移酶MAE_15850、谷胱甘肽還原酶MAE_46260和類糖基轉(zhuǎn)移酶MAE_13100)的表達(dá)量上升,表明阿莫西林觸發(fā)藻細(xì)胞的抗氧化應(yīng)激及解毒反應(yīng)。本文的研究結(jié)果表明,阿莫西林在其現(xiàn)有水環(huán)境污染濃度下,具有促進(jìn)銅綠微囊藻暴發(fā)的潛在可能。
[Abstract]:Due to the continuous use and discharge of antibiotics, antibiotic pollutants are frequently detected in natural water environment. Blue algae have prokaryotic cell structure and are sensitive to antibiotics. Therefore, in addition to nitrogen, phosphorus and other conventional water environmental factors, antibiotics may also become a new environmental factor to regulate the occurrence of cyanobacteria Shui Hua. In this paper, the widely distributed blue algae Shui Hua model species Microcystis aeruginosa was selected as the target algae species, and amoxicillin, a typical antibiotic widely detected in water environment, was selected as the target antibiotic. To study the regulatory effects of amoxicillin on the growth, toxicity and various physiological functions of Microcystis aeruginosa at the existing pollution level, and to verify the long-term nature of the above regulatory effects through semi-continuous culture experiments. The mechanism of action was discussed by proteome. When the exposure concentration of amoxicillin was 100 ng/L and 300 ng/L, the chlorophyll a content of Microcystis aeruginosa under short-term exposure was significantly higher than that of the control group (p0.05), and the gene psbA, related to photosynthesis was significantly higher than that of the control group (p0.05). The expression of psaB and rbcL was also up-regulated. The indexes indicating photosynthetic activity (Fv/Fm and rETRmax) also showed an upward trend under long-term exposure to amoxicillin. Proteome analysis further showed that the proteins encoded by psbA,psaB and rbcL genes were also up-regulated. The above results showed that amoxicillin could increase the photosynthetic activity of Microcystis aeruginosa at environmental concentration, both short-term and long-term exposure. Photosynthesis stimulation increases energy synthesis, which in turn leads to an increase in the growth rate of algae cells and the production of microcystins. This may be related to the toxic excitatory effect of low concentration amoxicillin on algal cells. The significantly enriched protein functional module showed that there was a significant interaction between microcystin synthase (mcyB), pan-stress protein (MAE_48380) and photosynthesis-related proteins (p0.05). This result further proves that there is a close relationship between MCs synthesis, cell stress and photosynthesis. Under the condition of low concentration amoxicillin exposure, the activities of (POD) and (GST) of SOD (POD) and S-transferase in algae cells were significantly increased (p0.05). The content of glutathione (GSH) also increased significantly (p0.05), indicating that amoxicillin produced oxidative pressure on algal cells and triggered the stress response of antioxidant system. Proteome analysis further confirmed the above results. Sod expression was up-regulated, as well as phase 鈪，

本文編號(hào)：2483622