| 菌株Desulfovibrio sp. CMX的DNRA性能和影响因素 |
| 摘要点击 1835 全文点击 911 投稿时间：2016-03-21 修订日期：2016-05-07 |
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| 中文关键词 硝酸盐异化还原为铵 硫酸盐还原菌 外加氮源 SO42- S2- |
| 英文关键词 dissimilatory nitrate reduction to ammonium(DNRA) sulfate-reducing bacteria extra nitrogen sources sulfate sulfide |
| 作者 | 单位 | E-mail | | 谢柄柯 | 大连理工大学环境学院, 工业生态与环境工程教育部重点实验室, 大连 116024 | xbk1024@163.com | | 张玉 | 大连理工大学环境学院, 工业生态与环境工程教育部重点实验室, 大连 116024 | zhangyu@dlut.edu.cn | | 王晓伟 | 大连理工大学环境学院, 工业生态与环境工程教育部重点实验室, 大连 116024 | | | 孙超越 | 大连理工大学环境学院, 工业生态与环境工程教育部重点实验室, 大连 116024 | | | 周集体 | 大连理工大学环境学院, 工业生态与环境工程教育部重点实验室, 大连 116024 | |
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| 中文摘要 |
| 微生物的硝酸盐异化还原为铵（DNRA）过程对自然界中铵根离子的存在和转化具有重要影响，然而关于SRB菌株DNRA过程影响和机制尚未探明. 本文考察了实验室筛选的SRB菌株Desulfovibrio sp. CMX的DNRA能力、影响因素及其影响机制. 结果表明，无外加氮源的情况下，分别以10 mmol·L-1 NO3-和NO2-作为唯一电子受体，菌株Desulfovibrio sp. CMX最终NH4+生成率分别达到85.8%和97.3%，且无N2和N2O等副产物产生. 实验探究了不同外加氮源、不同初始浓度的SO42-、S2-对菌株DNRA过程的影响. 酵母浸粉作为外加氮源可促进菌株的生长和代谢从而促进菌株DNRA过程；SO42-对于NO3-还原为NO2-阶段起促进作用，而对NO2-还原为NH4+阶段起抑制作用，综合两方面影响，最终表现出对菌株DNRA过程的抑制作用；S2-对菌株生长及DNRA过程都表现出抑制作用，且S2-浓度越高抑制作用越强，当S2-浓度达到6 mmol·L-1 后，S2-对于NO3-还原为NO2-阶段的抑制作用强于NO2-还原为NH4+阶段的抑制作用，NO3-还原为NO2-速率低于NO2-还原为NH4+速率，此时体系中不再有NO2-的积累. |
| 英文摘要 |
| The process of dissimilatory nitrate reduction to ammonium (DNRA) plays an important role in the presence and conversion of ammonium ions in nature. However, the influencing factors and mechanisms of DNRA process in sulfate-reducing bacteria (SRB) have not yet been identified. The ability, influencing factors and mechanisms of DNRA was investigated in Desulfovibrio sp. CMX isolated previously in our laboratory. The results showed that the production rate of ammonium reached 85.8% and 97.3% respectively with NO3- and NO2- (10 mmol·L-1) as the sole electron donor and nitrogen source. Meanwhile, there was no by-products such as N2 and N2O. Then the effects of different extra nitrogen sources and initial concentrations of sulfate and sulfide on DNRA process were also investigated. As a result, extra nitrogen, yeast extract, could promote DNRA process by improving both growth and metabolism of the strain. In another study, sulfate promoted the nitrate reduction stage while inhibited the nitrite reduction. Overall, the DNRA process by Desulfovibrio sp. CMX was inhibited by sulfate. In addition, both the growth and two stages of the DNRA process were inhibited in the presence of sulfide. Dose effect of sulfide was observed. Inhibition was enhanced with the increase of sulfide concentration. It's noticeable that the inhibition on nitrate reduction was stronger than the inhibition on nitrite reduction with 6 mmol·L-1 of sulfide, leading to the lower reduction rate of nitrate than that of nitrite. In this condition, no accumulation of nitrite was observed in the system. |
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