Enhancement of denitrification performance with reduction of nitrite accumulation and N2O emission by Shewanella oneidensis MR-1 in microbial denitrifying process.
Enhancement of denitrification performance with reduction of nitrite accumulation and N2O emission by Shewanella oneidensis MR-1 in microbial denitrifying process.
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DOI：
10.1016/j.watres.2019.115242
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发表时间：
2019-10
期刊：
影响因子：
12.8
通讯作者：
Meng Jiang;Xiong Zheng;Yinguang Chen
中科院分区：
文献类型：
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作者：
Meng Jiang;Xiong Zheng;Yinguang Chen
据报道，生物反硝化（即微生物将硝酸盐还原为气态氮）受到操作和环境参数的影响，例如碳源类型、pH 值和温度。本文对Shewanella oneidensis MR-1通过消除亚硝酸盐积累和一氧化二氮排放来增强反硝化性能进行了研究，并探讨了其机制。结果发现S. oneidensisMR-1本身具有有限的硝酸盐去除能力，但它在经过充分研究的反硝化菌（副球菌脱氮菌）的反硝化系统中的存在，明显提高了硝酸盐去除效率（从65.3％到97.8％），并减少了亚硝酸盐积累（从0.67到不可检测）和N2O生成（从8.87μm/mM-TN到不可检测）。机理研究表明S. oneidensisMR-1通过在细胞间形成纳米管来促进电子转移活性，从而导致反硝化酶活性、碳源代谢、ATP水平和细胞活力的增加。由于S增强了电子的产生、转移和消耗。 oneidensisMR-1，因此实现了反硝化性能的提高，同时减少了亚硝酸盐积累和N2O排放。最后，S增强了反硝化性能。 oneidensisMR-1通过实验室地下水处理实验得到验证。这项研究表明了 S 的潜在作用。 oneidensisMR-1可加速氮地球化学循环中的硝酸盐生物转化，并增加对硝酸盐污染的生物处理，同时有害中间体（亚硝酸盐和N2O）的积累可忽略不计。
Bio-denitrification (i.e., microbial reduction of nitrate to gaseous nitrogen) is usually reported to be affected by operating and environmental parameters, such as carbon source type, pH value, and temperature. In this paper, the enhancement of denitrification performance with the elimination of nitrite accumulation and nitrous oxide emission byShewanella oneidensisMR-1 were investigated and the mechanisms were explored. It was found thatS. oneidensisMR-1 itself had marginal nitrate removal capacity, but its presence in the denitrification system of a well-studied denitrifier(Paracoccus denitrificans) obviously enhanced nitrate removal efficiency (from 65.3% to 97.8%) and reduced nitrite accumulation (0.67 against none-detectable) and N2O generation (from 8.87 μm/mM-TN to none-detectable). The mechanism study showed thatS. oneidensisMR-1 promoted electrons transfer activity via the formation of nanotube between cells, which resulted in the increase of denitrification enzymes activity, carbon source metabolism, ATP level and cell viability. As the generation, transfer and consumption of electrons were enhanced byS. oneidensisMR-1, the improvement of denitrification performance with reduction of nitrite accumulation and N2O emission was therefore achieved. Finally, the performance of denitrification enhanced byS. oneidensisMR-1 was testified by laboratory groundwater treatment experiment. This study suggested the potential role ofS. oneidensisMR-1 in accelerating nitrate bio-transformation in nitrogen geochemical cycle and increasing bio-treatment of nitrate contamination with negligible harmful intermediates (nitrite and N2O) accumulation.