A centrifuge tube reactor for the determination of bacterial methane oxidation enrichment factors without influence of diffusion related isotope fractionation.
A centrifuge tube reactor for the determination of bacterial methane oxidation enrichment factors without influence of diffusion related isotope fractionation.
复制标题
DOI：
10.1016/j.scitotenv.2018.12.283
复制
发表时间：
2019-04
期刊：
影响因子：
--
通讯作者：
S. Schulte;M. Jochmann;J. Wolbert;T. Gehrke;Torsten C. Schmidt
中科院分区：
文献类型：
--
作者：
S. Schulte;M. Jochmann;J. Wolbert;T. Gehrke;Torsten C. Schmidt
通过对填埋场厌氧区和覆盖层表层的甲烷化合物特定稳定同位素分析，可以估算填埋场甲烷的生物转化。除了这两个输入参数之外，仅需要关于细菌甲烷氧化的碳同位素分馏的知识（富集因子（ε））。然而，许多因素和条件已被描述为影响ε。这些包括温度、应用的垃圾填埋场覆盖物、表达的甲烷单加氧酶（MMO）类型和细胞密度。在这项工作中，我们研究了微生物甲烷氧化与温度和甲烷营养型富集培养的类型。使用新设计的装置来克服潜在的CH 4-底物限制，例如扩散，其可能通过不适当和不均匀的混合影响ε的测定值。根据甲烷和二氧化碳的稳定碳同位素分析确定了同位素分馏。得到的同位素分馏值为ε22°C= −0.0136 ± 0.0036。此外，首次通过流动注射分析同位素比质谱法对细菌细胞团进行批量稳定同位素分析。
Biotransformation of methane at landfill sites can be estimated by applying compound specific stable isotope analysis of methane from the anaerobic and the cover layer surface zone. Next to these two input parameters, merely the knowledge of the carbon isotopic fractionation of the bacterial methane oxidation in terms of the enrichment factor (ε) is required. However, many factors and conditions have been described to affectε. These include temperature, the applied landfill cover, the type of expressed methane monooxygenase (MMO), and cell density. In this work we investigated the microbial methane oxidation with respect to temperature and type of methanotrophic enrichment culture. A newly designed setup was used to overcome potential CH4-substrate limitations such as diffusion that could affect the determined values ofεby improper and inhomogeneous mixing. The isotopic fractionation was determined based on the stable carbon isotope analysis of methane and carbon dioxide. The obtained value for isotopic fractionation wasε22°C= −0.0136 ± 0.0036. Also for the first time, bulk stable isotope analysis of bacterial cell mass was performed by flow injection analysis isotope ratio mass spectrometry.