Using stable isotopes and gas concentrations for independent constraints on microbial methane oxidation at Arctic Ocean temperatures
Using stable isotopes and gas concentrations for independent constraints on microbial methane oxidation at Arctic Ocean temperatures
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使用稳定同位素和气体浓度对北冰洋温度下微生物甲烷氧化进行独立约束
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
B. Loose
中科院分区：
文献类型：
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作者：
C. Uhlig;B. Loose
含氧水体中甲烷的微生物氧化作用是控制海洋向大气释放的溶解甲烷量的重要因素。我们探索了使用稳定同位素甲烷峰值来量化北极海水样品中的甲烷氧化速率。用Picarro G2201‐i型腔环下光谱仪测定了箔培养箱顶空样品的甲烷浓度和同位素比值。甲烷质量平衡和稳定同位素比值的变化是甲烷氧化的独立约束条件。当分馏因子为1.025时，用两种方法测定的氧化速率常数在同位素比率的微小变化（例如，10‰）范围内一致。对于超出校准范围的同位素比率的较大变化（例如90‰），方法出现分歧。速率常数低至0.01 d−1，具有很高的统计支持度。在阿拉斯加乌特基亚维克的冰下海水中，通过从每个孵育容器中重复取样，成功地测试了稳定同位素红外光谱法测定箔状孵育箱中甲烷氧化（ISMOFI）。根据添加同位素峰的数量，我们确定了原位甲烷浓度下的氧化速率为0.15±0.02 nmol L−1 d−1，最大氧化电位为271±41 nmol L−1 d−1。ISMOFI方法允许在单个培养箱中从几天到几个月不等的孵化时间。该方法可运输，适用于各种野外或海上实验室环境，避免使用放射性同位素和有毒化学品等有害物质。
Microbial oxidation of methane in oxic water bodies is an important control on the amount of dissolved methane which is released from the ocean to the atmosphere. We explored the use of stable isotope methane spikes to quantify methane oxidation rates in Arctic seawater samples. A Picarro G2201‐i cavity ring‐down spectrometer was used to determine methane concentration and isotope ratios from headspace samples in foil incubators. The methane mass balance and the change in stable isotope ratios served as independent constraints on methane oxidation. For a fractionation factor of 1.025 oxidation rate constants determined with both methods agreed within 20% for small changes in isotope ratio (e.g., 10‰). For large changes in isotope ratio (e.g., 90‰), which was outside the calibration range, methods diverged. Rate constants down to 0.01 d−1 could be resolved with high statistical support. Stable isotope infrared spectroscopy to determine methane oxidation in foil incubators (ISMOFI) was successfully tested on under ice seawater from Utqiagvik, Alaska, by repeated sampling from each incubation vessel. Depending on the amount of isotope spike added, we determined oxidation rates of 0.15 ± 0.02 nmol L−1 d−1 at in situ methane concentration and a maximal oxidation potential of 271 ± 41 nmol L−1 d−1. The ISMOFI method permits variable incubation durations from days to months in a single incubator. The method is transportable and applicable in a variety of field or seagoing laboratory environments, and it avoids the use of hazardous substances such as radioisotopes and toxic chemicals.
哥特兰深海和兰索特深海（波罗的海中部）氧化还原区内的中上层微生物甲烷氧化的比较研究
影响因子：
4.9
作者：
Jakobs G;Rehder G;Jost G;Kießlich K;Labrenz M;Schmale O.
通讯作者：
Schmale O.
影响因子：
18.3
作者：
Crespo-Medina, M.;Meile, C. D.;Joye, S. B.
通讯作者：
Joye, S. B.