过表达亚硝酸盐还原酶的重组大肠杆菌辅助污水短程硝化

发布时间：2018-02-21 09:25

本文关键词： 亚硝酸盐还原酶大肠杆菌重组短程硝化污水污泥脱氮　出处：《微生物学报》2017年12期 　论文类型：期刊论文

【摘要】：【目的】为了体现并突出亚硝酸盐还原酶在污水脱氮以及短程硝化中的重要性,对过表达亚硝酸盐还原酶的大肠杆菌进行了污水脱氮的研究。【方法】通过转化带有亚硝酸盐还原酶基因的重组质粒,将亚硝酸盐还原酶在大肠杆菌中过表达,通过分析重组大肠杆菌的产物研究了该酶的表达及还原亚硝酸盐的情况,通过将该重组菌与已报道的硝化-反硝化细菌或生活污水进行混合培养,研究重组菌用于辅助氨氮去除的短程硝化能力。【结果】重组大肠杆菌能正确表达亚硝酸盐还原酶,OD600=2.0的菌悬液在2 h内还原约1 mmol/L的亚硝酸盐,并产生几乎等量的一氧化氮;重组大肠杆菌与Acinetobacter sp.YF14菌株等比例混合时,12 h能够提高氨氮脱氮效率约(36.0±7.4)%,且在4 h时,最大亚硝酸盐的积累量减少37%;重组大肠杆菌(OD600=1.0)12 h内能够提高污水厂活性污泥的脱氮效率约(31.0±5.7)%,且未检测到亚硝酸盐和硝酸盐的积累;溶氧水平对于亚硝酸盐还原酶重组菌辅助脱氮具有明显的影响,中等溶氧量[(6.4?0.7)mg/L]时脱氮效果最好。【结论】过表达亚硝酸盐还原酶的大肠杆菌可以提高污水脱氮的短程硝化能力。
[Abstract]:[Objective] to highlight the importance and nitrite reductase in wastewater denitrification and nitrification in the overexpression of nitrite reductase of Escherichia coli were studied for nitrogen removal wastewater. [method] by transformation with nitrite reductase gene recombinant plasmid, the nitrite reductase expression in Escherichia coli, the recombinant product analysis Escherichia coli expression of the enzyme and the reduction of nitrite, the nitrification of the recombinant bacteria and denitrifying bacteria have been reported or sewage mixed culture, the research of recombinant bacteria for nitrification ability of auxiliary ammonia removal. [result] recombinant Escherichia coli can correctly express nitrite reductase, OD600=2.0 bacteria suspension of nitrite reduction of about 1 mmol/L solution within 2 h, and almost the same amount of nitric oxide; recombinant Escherichia coli Acineto Hybrid bacter sp.YF14 strain ratio, 12 h can improve the nitrogen removal efficiency of ammonia nitrogen is about (36 + 7.4)%, and in 4 h, the maximum accumulation of nitrite reduced 37%; recombinant Escherichia coli (OD600=1.0) within 12 h of activated sludge of a sewage treatment plant can improve the nitrogen removal efficiency of about (31 + 5.7)%, and did not detect nitrate and nitrite accumulation; dissolved oxygen levels for nitrite reductase recombinant auxiliary nitrogen has obvious influence, medium dissolved oxygen [(6.4? 0.7) mg/L] when the nitrogen removal effect is the best. [Conclusion] over expression of nitrite reductase of Escherichia coli can improve the ability of nitrification and denitrification of wastewater.

【作者单位】：曲阜师范大学生命科学学院;
【基金】：山东省自然科学基金青年基金(ZR2012CQ011) 曲阜师范大学校级基金资助(XJ201108)~~
【分类号】：X172;X703

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