磁场对E.cloacae与E.aerogenes厌氧发酵产氢的影响研究

发布时间：2018-04-26 05:38

本文选题：磁场 + 阴沟肠杆菌　；参考：《湘潭大学》2015年硕士论文

【摘要】：氢气是清洁能源的突出代表,是未来最理想的燃料之一。暗发酵生物制氢法具有工艺简单、适应性强的特点,成为了最具潜力的制氢方法之一,但该法受各方面因素影响而限制了产氢率,所以仍不足以使其产业化。有相关研究指出,磁场作用可以促进细胞酶活性与微生物生长,从而提高对污染物的降解效果,但有关磁场对厌氧生物发酵产氢的影响还未见报道。本文在两株产氢菌E.cloacae和E.aerogenes厌氧中温(37±1℃)发酵葡萄糖产氢体系中引入磁场,在优化产氢条件的基础上,探讨了不同磁场(单N极磁场、N-S极磁场)和磁场强度(0mT、8mT、15mT、25mT、42mT、56mT)对该两株细菌的生长及厌氧发酵产氢特性的影响,并通过测定代谢产物、脱氢酶活性、16S rDNA测序等手段,初步探讨了磁场对E.cloacae和E.aerogenes厌氧发酵葡萄糖产氢的作用机制,得到如下的结论:(1)磁场对E.cloacae的生长有促进作用,在56mT N极磁场条件下细菌的生长量比空白最大提高了17.5%,56mT N-S极磁场则最大提高了19.1%。(2)N-S极磁场能提高细菌厌氧发酵葡萄糖产氢效率:在10g/L葡萄糖的条件下,42mT N-S极磁场对E.cloacae和E.aerogenes的产氢率提高得最大,分别是0.751和0.762mol氢/mol葡萄糖,比空白分别提高了6.6%和9%;最大产氢速率分别为10.27和7.31m L/h,提高了11.5%和14.9%。(3)用Gompertz公式较好地拟合了E.cloacae和E.aerogenes的产氢过程,由Gompertz参数可知,在42mT N-S极磁场作用下该两株细菌的累积产氢量分别比空白提高了7.9%和8.7%;用双倒数法求解Monod方程中的动力学参数,所得曲线的拟合优度较高,说明不论是否在磁场作用下E.aerogenes对葡萄糖的降解都符合该动力学方程。(4)E.cloacae和E.aerogenes在42mT N-S极磁场条件下生成的丁二醇分别提高了34.3%和12.5%,生成的乙醇分别提高了4.5%和2.9%,但这些产物的积累在一定程度上可能会限制细菌的产氢效果。(5)磁场对细菌外貌和基因无显著影响,但可促进细菌增殖,而且也提高了脱氢酶的活性,因而加强了细菌的产氢能力。42mT N-S极磁场对E.cloacae和E.aerogenes细菌生长量最大提高了5.1%和14.4%,对脱氢酶活性也分别最大提高了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.
【学位授予单位】：湘潭大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ116.2;TQ920.6

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