本文關鍵詞：HN-02菌脫氮性能與抗氧化酶體系對鹽脅迫響應特征研究　出處：《成都理工大學》2015年碩士論文　論文類型：學位論文

  更多相關文章： 鹽脅迫 生物脫氮 異養(yǎng)硝化-好氧反硝化 抗氧化酶系統(tǒng)

【摘要】：目前,氮素是造成我國水體污染的主要原因之一,脫氮技術,特別是廢水生物脫氮技術因其具有經(jīng)濟、高效、無害的特點,引起世界各國的普遍關注。脫氮微生物是廢水生物脫氮技術的核心,但其脫氮效率容易受水質條件如鹽度等脅迫因素影響。本研究基于實驗室從淡水環(huán)境篩選的異養(yǎng)硝化-好氧反硝化菌HN-02(Aeromonas hydrophila sp.)展開,研究其在不同鹽度沖擊下(Na Cl濃度0~20g/L)的脫氮性能和抗氧化酶體系的響應變化特征,探究鹽分脅迫下HN-02菌株的響應機制;此外,通過對HN-02菌株進行不同鹽度馴化,比較研究了馴化后HN-02菌株脫氮特性和抗氧化酶響應特征。研究結果表明:(1)HN-02是一株耐鹽菌,可在0~20g/L的鹽度沖擊下生長、繁殖。菌株生長狀況和脫氮速率與鹽濃度呈反相關,6h內,鹽度0 g/L、5 g/L、10g/L、15g/L和20g/L氨氮降解速率分別為3.66 mg/L·h、2.95 mg/L·h、2.82 mg/L·h.1.92 mg/L·h和1.08 mg/L·h。(2)HN-02在遭遇鹽脅迫時,機體內抗氧化酶的應急反應是系統(tǒng)性的,抗氧化酶體系如SOD(superoxide dismutase,超氧化物歧化酶)和POD(peroxidase,過氧化物酶)是協(xié)同作用的。就抗氧化酶體系抵抗鹽度脅迫敏感性而言:SODPOD,但就酶活力變化幅度來看CATSODPOD,CAT(catalase,過氧化物酶)活力調節(jié)幅度分別較SOD、POD高32.06 U/g和117.24 U/g。(3)馴化后HN-02生長狀況和脫氮速率仍與鹽度濃度成反相關,6h內鹽度5 g/L、10 g/L、15g/L和20 g/L的OD600和生長速率分別為0.647(0.097 h-1)、0.590(0.087 h-1),0.522(0.076 h-1)和0.233(0.028 h-1);生長速率分別較馴化前提高0.058 h-1(148.93%)、0.054 h-1(160.20%)、0.056 h-1(276.03%)和0.025h-1(773.68%);其脫氮速率分別為5.17mg/L·h,5.21 mg/L·h,3.87 mg/L·h和2.14mg/L·h,分別較馴化前提高2.22 mg/L·h(75.14%),2.39 mg/L·h(85.04%),1.95 mg/L·h(101.25%)和1.06 mg/L·h(98.10%)。(4)SOD在HN-02耐鹽性方面起到了關鍵作用,鹽度馴化后HN-02能夠迅速的誘導啟動SOD抗氧化酶體系來進行防御。SOD在整個脅迫時期都將發(fā)揮作用,并且在脅迫初段表現(xiàn)的更為敏感。(5)馴化后,鹽脅迫下POD的活力受抑制的程度大于SOD,POD的誘導產(chǎn)生能力可能小于SOD。同時,推斷抗氧化酶系統(tǒng)發(fā)揮作用的順序是:SODPODCAT,但是當POD不足以清除H2O2危害時,CAT和POD會同時協(xié)同作用調節(jié)機體不利影響,解除或緩解脅迫。(6)15 g/L可能是HN-02解除或者緩解鹽度脅迫的臨界點,鹽度15g/L以內SOD的活力隨著鹽度升高而提高,最大平均增加速率(鹽度15g/L)為30.05U/g·h。當鹽度高于15 g/L,POD和CAT活性受到抑制。(7)HN-02-05、HN-02-10、HN-02-15和HN-02-20在遭受20 g/L鹽度沖擊時,氨氮降解能力和生長狀況不一致。其平均生長速率分別為0.027 h-1,0.033 h-1,0.058 h-1和0.013 h-1,其中HN-02-15生長速率最快。就脫氮能力而言,馴化鹽度越接近沖擊鹽度(20g/L)脫氮效果越好,其氨氮降解速率分別為1.71 mg/L·h、1.91 mg/L·h、5.92 mg/L·h和6.99 mg/L·h,其中HN-02-20效果最好�，F(xiàn)階段,異養(yǎng)硝化—好氧反硝化菌應用于高鹽廢水脫氮還處于研究初期,其耐鹽機理的研究十分缺乏。加強微生物在鹽度脅迫下脫氮特性和抗氧化酶體系響應特征研究,有助于完善鹽脅迫下廢水生物脫氮的機理,為應對策略與技術研發(fā)提供參考。
[Abstract]:At present, nitrogen is one of the main causes of water pollution in China, nitrogen removal technology, especially wastewater biological nitrogen removal technology because of its economic, efficient, harmless, caused widespread concern of the world. Microbial nitrogen removal is the core technology for nitrogen removal wastewater, but the removal efficiency of nitrogen is easily affected by water conditions as salinity stress factors. This research is based on the screening of heterotrophic nitrification from freshwater environment laboratory aerobic denitrifying bacteria HN-02 (Aeromonas hydrophila sp.), on the impact of different salinity (Na Cl concentration 0~20g/L) nitrogen removal performance and antioxidant system response characteristics, response mechanisms under salt stress strain HN-02; in addition, the effects of salinity on HN-02 was domesticated of domesticated strain HN-02 nitrogen removal characteristics and antioxidant response characteristics. The results show that: (1) HN-02 is a strain of resistance Salt bacteria can grow, in 0~20g/L under salinity shock propagation. The growth of strains and the denitrification rate was negatively correlated with salt concentration, 6h, salinity of 0 g/L, 5 g/L, 10g/L, 15g/L and 20g/L ammonia degradation rate were 3.66 mg/L, 2.95 h, mg/L, h, mg/L, h.1.92, mg/L 2.82 h and 1.08 mg/L h. (2) HN-02 in the event of emergency response to salt stress, antioxidant enzymes in the body is systemic, antioxidant enzyme system such as SOD (superoxide dismutase, superoxide dismutase (peroxidase) and POD, peroxidase). It is the synergistic effect of antioxidant enzyme system resistance to salinity stress sensitivity: SODPOD, but the amplitude change of enzyme activity of CATSODPOD, CAT (catalase, peroxidase) activity amplitude compared with SOD POD, 32.06 U/g and 117.24 U/g. (3 HN-02) after acclimation growth and nitrogen removal rate is inversely correlated with salinity concentration, salinity in 6h 5 g/L, 10 g/L 15g/L. 鍜，

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