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磁場對E.cloacae與E.aerogenes厭氧發(fā)酵產氫的影響研究

發(fā)布時間:2018-04-26 05:38

  本文選題:磁場 + 陰溝腸桿菌 ; 參考:《湘潭大學》2015年碩士論文


【摘要】:氫氣是清潔能源的突出代表,是未來最理想的燃料之一。暗發(fā)酵生物制氫法具有工藝簡單、適應性強的特點,成為了最具潛力的制氫方法之一,但該法受各方面因素影響而限制了產氫率,所以仍不足以使其產業(yè)化。有相關研究指出,磁場作用可以促進細胞酶活性與微生物生長,從而提高對污染物的降解效果,但有關磁場對厭氧生物發(fā)酵產氫的影響還未見報道。本文在兩株產氫菌E.cloacae和E.aerogenes厭氧中溫(37±1℃)發(fā)酵葡萄糖產氫體系中引入磁場,在優(yōu)化產氫條件的基礎上,探討了不同磁場(單N極磁場、N-S極磁場)和磁場強度(0mT、8mT、15mT、25mT、42mT、56mT)對該兩株細菌的生長及厭氧發(fā)酵產氫特性的影響,并通過測定代謝產物、脫氫酶活性、16S rDNA測序等手段,初步探討了磁場對E.cloacae和E.aerogenes厭氧發(fā)酵葡萄糖產氫的作用機制,得到如下的結論:(1)磁場對E.cloacae的生長有促進作用,在56mT N極磁場條件下細菌的生長量比空白最大提高了17.5%,56mT N-S極磁場則最大提高了19.1%。(2)N-S極磁場能提高細菌厭氧發(fā)酵葡萄糖產氫效率:在10g/L葡萄糖的條件下,42mT N-S極磁場對E.cloacae和E.aerogenes的產氫率提高得最大,分別是0.751和0.762mol氫/mol葡萄糖,比空白分別提高了6.6%和9%;最大產氫速率分別為10.27和7.31m L/h,提高了11.5%和14.9%。(3)用Gompertz公式較好地擬合了E.cloacae和E.aerogenes的產氫過程,由Gompertz參數(shù)可知,在42mT N-S極磁場作用下該兩株細菌的累積產氫量分別比空白提高了7.9%和8.7%;用雙倒數(shù)法求解Monod方程中的動力學參數(shù),所得曲線的擬合優(yōu)度較高,說明不論是否在磁場作用下E.aerogenes對葡萄糖的降解都符合該動力學方程。(4)E.cloacae和E.aerogenes在42mT N-S極磁場條件下生成的丁二醇分別提高了34.3%和12.5%,生成的乙醇分別提高了4.5%和2.9%,但這些產物的積累在一定程度上可能會限制細菌的產氫效果。(5)磁場對細菌外貌和基因無顯著影響,但可促進細菌增殖,而且也提高了脫氫酶的活性,因而加強了細菌的產氫能力。42mT N-S極磁場對E.cloacae和E.aerogenes細菌生長量最大提高了5.1%和14.4%,對脫氫酶活性也分別最大提高了8.2%和20.2%。
[Abstract]:Hydrogen is the outstanding representative of clean energy and one of the most ideal fuels in the future. Dark fermentation biological hydrogen production process has the characteristics of simple process and strong adaptability, and it has become one of the most potential hydrogen production methods. However, the hydrogen production rate is limited by various factors, so it is still not sufficient for its industrialization. Some studies have pointed out that magnetic field can promote cell enzyme activity and microbial growth, thus improving the degradation of pollutants, but the effect of magnetic field on anaerobic fermentation hydrogen production has not been reported. In this paper, magnetic field was introduced into the medium temperature medium temperature of E.cloacae and E.aerogenes to ferment hydrogen from glucose, and the conditions of hydrogen production were optimized. The effects of different magnetic fields (single N pole magnetic field N-S pole magnetic field) and magnetic field intensity (0 mTT ~ (8) T ~ (15) T ~ (2 +) on the growth of the two strains and their anaerobic fermentative hydrogen production characteristics were investigated. The metabolic products and dehydrogenase activity were sequenced by 16s rDNA. The mechanism of magnetic field on hydrogen production of E.cloacae and E.aerogenes by anaerobic fermentation of glucose was discussed. The conclusion is as follows: magnetic field can promote the growth of E.cloacae. Under the condition of 56mT N pole magnetic field, the maximum increase of bacteria growth is 17.5mT N-S pole magnetic field and 56mT N-S pole magnetic field, and the maximum increase of 19.1%.(2)N-S polarity magnetic field can improve the hydrogen production efficiency of anaerobic fermentation glucose of bacteria: 42mT N-S pole magnetic field pair under the condition of 10g/L glucose. The hydrogen production rate of E.cloacae and E.aerogenes is the highest. The maximum hydrogen production rate was 10.27 and 7.31m L / h, which increased by 11.5% and 14.9%, respectively. The hydrogen production process of E.cloacae and E.aerogenes was fitted well by Gompertz formula. The Gompertz parameter indicated that the hydrogen production process of E.cloacae and E.aerogenes was better fitted by using the Gompertz formula, the maximum hydrogen production rate was 10.27 and 7.31 m L / h, respectively, and the maximum hydrogen production rate was 10.27 and 7.31 m L / h, respectively. Under the action of 42mT N-S polar magnetic field, the cumulative hydrogen production of the two strains increased by 7.9% and 8.7%, respectively, and the kinetic parameters of the Monod equation were solved by the two-reciprocal method. The results show that the degradation of glucose by E.aerogenes under magnetic field or not accords with the kinetic equation. E.cloacae and E.aerogenes increased 34.3% and 12.5%, respectively, and ethanol increased by 4.5% and 2.9%, respectively, under the conditions of 42mT N-S polarity magnetic field. The accumulation of these products may limit the hydrogen production of bacteria to some extent.) the magnetic field has no significant effect on the appearance and gene of bacteria. But it could promote the proliferation of bacteria and increase the activity of dehydrogenase. Therefore, the hydrogen production ability of bacteria. 42mT N-S polar magnetic field increased the growth of E.cloacae and E.aerogenes bacteria by 5.1% and 14.4%, and the activity of dehydrogenase increased by 8.2% and 20.2% respectively.
【學位授予單位】:湘潭大學
【學位級別】:碩士
【學位授予年份】:2015
【分類號】:TQ116.2;TQ920.6

【參考文獻】

相關博士學位論文 前1條

1 易維潔;碳源對水稻土中鐵還原特征和鐵還原菌多樣性的影響[D];西北農林科技大學;2011年

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