| 引用本文: | 陈小锋,王润竹,陈静,朱诗雅.太湖沉积物中厌氧铁氨氧化过程.湖泊科学,2023,35(5):1604-1612. DOI:10.18307/2023.0521 |
| Chen Xiaofeng,Wang Runzhu,Chen Jing,Zhu Shiya.Ferric iron reduction coupled to anaerobic ammonium oxidation in the sediments of Lake Taihu. J. Lake Sci.2023,35(5):1604-1612. DOI:10.18307/2023.0521 |
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| 摘要: |
| 铁氨氧化(Feammox)是近年来发现的一种新型的厌氧氨氧化耦合三价铁[Fe(Ⅲ)]还原的脱氮途径,该途径对于水生态系统中的氮素自净可能有着重要的作用。但是相对于废水处理和农田土壤,目前自然水体中Feammox相关的研究相对甚少。为此,本研究采集太湖不同区域沉积物进行厌氧培养,并借助同位素技术和分子生物学等手段,对沉积物中铁、氮循环相关细菌、Feammox影响因素以及潜在速率等进行了探究。厌氧培养过程中,亚铁[Fe(Ⅱ)]和各形态氮的浓度以及沉积物形态和颜色的变化,表明沉积物中发生了Feammox反应,并且硝酸盐(NO-3)是铵(NH+4)氧化的重要产物之一。不同氨氮(NH+4-N)添加量的厌氧培养实验表明,NH+4可以促进Fe(Ⅲ)的还原,但过量的NH+4可能会产生抑制效应。不同Fe(Ⅲ)添加量的各处理中,NH+4-N浓度的变化无显著差异(P>0.05,ANOVA),但是高Fe(Ⅲ)添加量的处理中,硝酸盐氮(NO-3-N)浓度显著高于其它处理(P<0.01,ANOVA),表明Fe(Ⅲ)的添加可以促进NH+4氧化为NO-3的过程。厌氧培养过程中,NO-3-N浓度急剧上升后又快速下降,伴随着反硝化功能相关的菌属相对丰度的大大增加,说明体系中可能发生了Feammox和反硝化的耦合。同位素富集培养结果表明,太湖不同区域沉积物均有较高的Feammox潜在速率(0.17~0.51 mg N/(kg·d)),表明Feammox在太湖氮素自净过程中可能发挥了重要的作用。 |
| 关键词: 铁氨氧化 沉积物 太湖 蓝藻水华 |
| DOI：10.18307/2023.0521 |
| 分类号: |
| 基金项目:国家自然科学基金项目(42177185)资助。 |
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| Ferric iron reduction coupled to anaerobic ammonium oxidation in the sediments of Lake Taihu |
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Chen Xiaofeng, Wang Runzhu, Chen Jing, Zhu Shiya
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School of Environmental Science and Engineering, Yangzhou University, Yangzhou 225127, P.R. China
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| Abstract: |
| Ferric iron [Fe(Ⅲ)] reduction coupled with anaerobic ammonium oxidation (Feammox), a novel nitrogen removal pathway discovered in recent years, may play an important role in nitrogen self-purification in aquatic ecosystems. However, current research on this process is mainly focused on wastewater treatment or agricultural soils, with limited studies in natural lakes. In this study, sediments collected from different areas of Lake Taihu were anaerobically cultured and the bacteria involved in the iron and nitrogen cycles, the factors influencing Feammox and the potential rates in the sediments were investigated using high-throughput sequencing and isotope technology. During anaerobic culture, changes in the concentrations of iron [Fe(Ⅱ)] and various forms of nitrogen, as well as the morphology and colour of the sediments, indicated the presence of Feammox in the sediments, with nitrate (NO-3) being an important product of ammonia (NH+4) oxidation. The addition of NH+4 can promote the reduction of Fe(Ⅲ), but excessive NH+4 can have an inhibitory effect. In the treatments with different Fe(Ⅲ) additions, there were no significant changes in NH+4-N (P>0.05, ANOVA). However, the NO-3-N concentration in the treatment with the highest Fe(Ⅲ) addition was significantly higher than in the other treatments (P<0.01, ANOVA), indicating that Fe(Ⅲ) addition could promote the production of NO-3-N. The concentration of NO-3-N increased sharply and then decreased rapidly during anaerobic culture, accompanied by a significant increase in the relative abundance of genera associated with denitrification, indicating that the coupling of Feammox and denitrification occurred in the system. The results of the isotope enrichment experiment showed that the potential rates of Feammox were relatively high in different regions of Lake Taihu (0.17-0.51 mg N/(kg·d)), indicating that Feammox may play an important role in the nitrogen self-purification of Lake Taihu. |
| Key words: Feammox sediments Lake Taihu cyanobacterial bloom |
