Dual nitrogen and oxygen isotope fractionation during anaerobic ammonium oxidation by anammox bacteria
ISME JOURNAL(2019)
摘要
Natural abundance of stable nitrogen (N) and oxygen (O) isotopes are invaluable biogeochemical tracers for assessing the N transformations in the environment. To fully exploit these tracers, the N and O isotope effects ( 15 ε and 18 ε) associated with the respective nitrogen transformation processes must be known. However, the N and O isotope effects of anaerobic ammonium oxidation (anammox), one of the major fixed N sinks and NO 3 − producers, are not well known. Here, we report the dual N and O isotope effects associated with anammox by three different anammox bacteria including “ Ca . Scalindua japonica ”, a putative marine species, which were measured in continuous enrichment culture experiments. All three anammox species yielded similar N isotope effects of NH 4 + oxidation to N 2 ( 15 ε NH4→N2 ) ranging from 30.9‰ to 32.7‰ and inverse kinetic isotope effects of NO 2 − oxidation to NO 3 − ( 15 ε NO2→NO3 = −45.3‰ to −30.1‰). In contrast, 15 ε NO2→N2 (NO 2 − reduction to N 2 ) were significantly different among three species, which is probably because individual anammox bacteria species might possess different types of nitrite reductase. We also report the combined O isotope effects for NO 2 − oxidation ( 18 E NO2→NO3 ) by anammox bacteria. These obtained dual N and O isotopic effects could provide significant insights into the contribution of anammox bacteria to the fixed N loss and NO 2 − reoxidation (N recycling) in various natural environments.
更多查看译文
关键词
Microbial ecology,Microbiology,Life Sciences,general,Ecology,Evolutionary Biology,Microbial Genetics and Genomics,Microbial Ecology
AI 理解论文
溯源树
样例
生成溯源树,研究论文发展脉络
Chat Paper
正在生成论文摘要