Anammox细菌铁还原代谢及群体感应现象的研究
发布时间：2019-01-18 10:37
【摘要】：厌氧氨氧化是Anammox菌体将NH4+和NO2-转化为N2的过程。与传统生物脱氮技术相比,厌氧氨氧化技术具有脱氮效率高、不需外加碳源、不需曝气、污泥产量低等优点而受到国内外研究者的广泛关注。但是,Anammox细菌具有倍增缓慢难以富集和环境敏感等缺点,这使其工业应用推广受到了限制。针对上述问题,本论文以Anammox菌体为研究对象,探寻了Anammox菌体的铁还原代谢途径；并通过探索群体感应现象对Anammox菌体生理特性的影响,开发了通过外源添加Anammox菌体颗粒污泥反应器(Anammox Granular Sludge Reactor, AGSR)上清液提高Anammox菌体氮去除能力、加速厌氧氨氧化启动的方法；分析了群体感应信号在维持菌体颗粒稳定和保持储存菌种活性中的作用。本论文的研究成果如下：(1)Anammox菌体具有铁还原能力,在本实验条件下,Anammox菌体铁还原的最适反应条件为pH=7时,以甲酸盐为电子供体,Fe(Ⅲ)-NTA为电子受体进行反应。其中,约有80%的铁还原酶定位于Anammox菌体的膜组分,20%铁还原酶活性存在于可溶性组分。菌体内厌氧氨氧化体铁还原活性占总体活性的51%。Anammox菌体在氮代谢同时铁还原反应中,氮代谢过程不会受到影响,但是其还原产生的Fe2+含量仅为铁还原组的7.02%。(2) AGSR上清液中含有群体感应信号C12-HSL。利用含C12-HSL的AGSR上清液制备反应器进水,能将厌氧氨氧化启动进程从80天缩短到66天。同时,Anammox细菌的氮负荷率(Nigrogen Loading Rate, NLR)也提高到对照组的1.6倍。此外,AGSR上清液还能促进反应器中菌体的胞外聚合物(Extracellular Polymeric Substances, EPS)分泌和Anammox菌体的富集,同时影响菌群演化。(3)群体感应信号能影响Anammox菌体的氮代谢活性,并通过调控EPS分泌影响Anammox菌体颗粒的强度、粒径和稳定性。利用香草醛和猪肾酰化酶对群体感应信号物质进行抑制,Anammox菌体的厌氧氨氧化活性(Specific Anammox Activity, SAA)从178.48 mg N/g VSS·d分别降低到156.66和156.51 mg N/g VSS·d。酶粗提物活性从2.33 μmol cytochrome c/min/mg protein降低到1.63和1.47 μmol cytochrome c/min/mg protein。抑制群体感应信号会造成菌体颗粒稳定性、粒径及强度的下降。这种稳定性的下降主要是由于EPS中的蛋白(Protein, PN)及多糖(Polysaccharide, PS)含量降低和PN/PS比例变化造成的。(4)群体感应信号有助于Anammox菌体在储藏条件下活性和血红素c (Heme c)含量的保持。分别在絮状和颗粒状Anammox菌体中外源添加10mg/LC12-HSL和1g/L猪肾酰化酶,并于室温(20℃)条件下储存90天,加入C12-HSL的Anammox絮状菌体活性比不加入外源物质储存后菌体活性高6.13%,而加入猪肾酰化酶去除群体感应信号的Anammox颗粒状菌体活性仅为对照组菌体活性的86.24%。加入C12-HSL的Anammox絮状菌体的酶粗提物活性提高了27.73%,而加入猪肾酰化酶的Anammox菌体颗粒的酶粗提物活性仅为对照组菌体活性的86.44%。群体感应信号还有助于Anammox菌体中Heme c含量的保持。加入C12-HSL信号储存的絮状Anammox菌体中Heme c含量比对照组高27.03%。而加入猪肾酰化酶后的Anammox颗粒状菌体中Heme c的含量仅为对照组菌体中Heme c含量的59.65%。
[Abstract]:The anaerobic ammoxidation is the process of converting NH4 + and NO2-into N2 by the Anammox cells. Compared with the traditional biological denitrification technology, the anaerobic ammoxidation technology has the advantages of high denitrification efficiency, no need of external carbon source, no need of aeration, low sludge yield and the like, and is widely concerned by the researchers at home and abroad. however, that Anammox bacteria have the disadvantage of being slow to accumulate and sensitive to the environment, which limit their industrial application. In the light of the above-mentioned problems, the paper, taking the Anammox thalli as the research object, explored the iron reduction and metabolic pathway of the Anammox thalli, and developed the Anammox Granular Saudge Reactor by adding the Anammox thalli granular sludge reactor through the study of the effect of the population induction on the physiological characteristics of the Anammox thalli. The method for improving the nitrogen removal capacity of the Anammox cell and accelerating the initiation of the anaerobic ammoxidation is carried out on the AGSR), and the effect of the population induction signal in the maintenance of the cell particle stability and the preservation of the activity of the storage strain is analyzed. The results of this paper are as follows: (1) The Anammox thalli has the ability of iron reduction. Under the conditions of this experiment, the optimum reaction conditions for the reduction of the Anammox thalli are pH = 7, and the acid salt is the electron donor, and the Fe (鈪，
本文编号：2410623
[Abstract]:The anaerobic ammoxidation is the process of converting NH4 + and NO2-into N2 by the Anammox cells. Compared with the traditional biological denitrification technology, the anaerobic ammoxidation technology has the advantages of high denitrification efficiency, no need of external carbon source, no need of aeration, low sludge yield and the like, and is widely concerned by the researchers at home and abroad. however, that Anammox bacteria have the disadvantage of being slow to accumulate and sensitive to the environment, which limit their industrial application. In the light of the above-mentioned problems, the paper, taking the Anammox thalli as the research object, explored the iron reduction and metabolic pathway of the Anammox thalli, and developed the Anammox Granular Saudge Reactor by adding the Anammox thalli granular sludge reactor through the study of the effect of the population induction on the physiological characteristics of the Anammox thalli. The method for improving the nitrogen removal capacity of the Anammox cell and accelerating the initiation of the anaerobic ammoxidation is carried out on the AGSR), and the effect of the population induction signal in the maintenance of the cell particle stability and the preservation of the activity of the storage strain is analyzed. The results of this paper are as follows: (1) The Anammox thalli has the ability of iron reduction. Under the conditions of this experiment, the optimum reaction conditions for the reduction of the Anammox thalli are pH = 7, and the acid salt is the electron donor, and the Fe (鈪，
本文编号：2410623
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