Molecular transformation of organic nitrogen in Antarctic penguin guano-affected soil.
Molecular transformation of organic nitrogen in Antarctic penguin guano-affected soil.
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DOI：
10.1016/j.envint.2023.107796
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发表时间：
2023-02
影响因子：
11.8
通讯作者：
Libin Wu;Ming Sheng;Xiaodong Liu;Zhangqin Zheng;S. Emslie;N. Yang;Xueying Wang;Yaguang Nie;Jing Jin;Q. Xie;Shuang Chen;Donghuan Zhang;Sihui Su;Shujun Zhong;Wei Hu;Junjun Deng;J. Zhu;Yulin Qi;Cong‐Qiang Liu;P. Fu
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作者：
Libin Wu;Ming Sheng;Xiaodong Liu;Zhangqin Zheng;S. Emslie;N. Yang;Xueying Wang;Yaguang Nie;Jing Jin;Q. Xie;Shuang Chen;Donghuan Zhang;Sihui Su;Shujun Zhong;Wei Hu;Junjun Deng;J. Zhu;Yulin Qi;Cong‐Qiang Liu;P. Fu
有机氮（ON）是地球氮循环的重要参与者。此前的研究表明，企鹅粪便为土壤增加了包括氮在内的丰富营养物质，极大地改变了南极洲无冰地区的生态环境。为了研究企鹅粪染土壤中ON的分子转化，我们收集了南极洲罗斯海地区无鸟粪风化土、企鹅群的现代鸟粪染土、废弃企鹅群的古代鸟粪染土和企鹅粪便，并利用傅里叶变换离子回旋质谱（FT-ICR MS）研究了水可提取的ON的化学成分。通过比较不同样品中ON的分子组成，我们发现风化土壤中ON化合物的数量很少（约4000个），而富含羧基的脂环类分子（cram类）则占主导地位。企鹅粪便向土壤中添加了大约10万个CHON、CHONS和CHN化合物，包括粪粪影响土壤中的类crama、类脂、脂肪/肽类分子和胺。企鹅粪便输入后，大分子继续降解，其他ON化合物往往被氧化为相对稳定的类cramm分子，这是受鸟粪影响的土壤中ON的重要转化过程。我们得出各种形式的ON在N循环中的作用是复杂多样的。结合以往的研究，氮最终转化为无机氮，从土壤中流失。失去的氮最终回到海洋和食物网，从而完成氮循环。本研究初步揭示了受企鹅粪影响的土壤ON的分子转化，对了解南极N循环具有重要意义。
Organic nitrogen (ON) is an important participant in the Earth’s N cycle. Previous studies have shown that penguin feces add an abundance of nutrients including N to the soil, significantly changing the eco-environment in ice-free areas in Antarctica. To explore the molecular transformation of ON in penguin guano-affected soil, we collected guano-free weathered soil, modern guano-affected soil from penguin colonies, ancient guano-affected soil from abandoned penguin colonies, and penguin feces from the Ross Sea region, Antarctica, and Fourier transform ion cyclotron mass spectrometry (FT-ICR MS) was used to investigate the chemical composition of water-extractable ON. By comparing the molecular compositions of ON among different samples, we found that the number of ON compounds (>4,000) in weathered soil is minimal, while carboxylic-rich alicyclic-like molecules (CRAM-like) are dominant. Penguin feces adds ON into the soil with > 10,000 CHON, CHONS and CHN compounds, including CRAM-like, lipid-like, aliphatic/ peptide-like molecules and amines in the guano-affected soil. After the input of penguin feces, macromolecules continue to degrade, and other ON compounds tend to be oxidized into relatively stable CRAM-like molecules, this is an important transformation process of ON in guano-affected soils. We conclude the roles of various forms of ON in the N cycle are complex and diverse. Combined with previous studies, ON eventually turns into inorganic N and is lost from the soil. The lost N ultimately returns to the ocean and the food web, thus completing the N cycle. Our study preliminarily reveals the molecular transformation of ON in penguin guano-affected soil and is important for understanding the N cycle in Antarctica.