Coupled sulfur and oxygen isotope insight into bacterial sulfate reduction in the natural environment
Coupled sulfur and oxygen isotope insight into bacterial sulfate reduction in the natural environment
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DOI：
10.1016/j.gca.2013.05.005
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发表时间：
2013-10-01
影响因子：
5
通讯作者：
Sivan, Orit
中科院分区：
文献类型：
--
作者：
Antler, Gilad;Turchyn, Alexandra V.;Sivan, Orit
我们提出了新的硫和氧同位素数据硫酸盐（三角洲S-34（SO 4）和三角洲O-18（SO 4），分别），从全球分布的海洋和河口孔隙流体。我们将这些数据与细菌硫酸盐还原（BSR）所涉及的生化步骤模型一起使用，以探索Delta O-18（SO 4）与Delta S-34（SO 4）图的斜率如何与净硫酸盐还原率（nSRR）相关在不同的自然环境中。我们的数据表明，nSRR与残余硫酸盐池中氧和硫同位素的相对演化斜率（δ O-18（SO 4）与δ S-34（SO 4））之间存在相关性，因此nSRR越高，斜率越低（硫同位素相对于氧同位素增加得更快）。我们结合联合收割机这些结果与以前发表的文献数据表明，这种相关性尺度超过许多数量级的nSRR。我们的模型的机制，BSR表明，在硫酸盐中的氧和硫同位素在自然环境中的BSR过程中的相对演变的关键参数是细胞内的亚硫酸盐氧化的速率。在硫酸盐还原快速的环境中，如河口和边缘海洋环境，这种亚硫酸盐再氧化是最小的，并且相对于S-34（SO 4），δ O-18（SO 4）的增加更慢。相比之下，在硫酸盐还原非常缓慢的环境中，例如深海沉积物，我们的模型表明亚硫酸盐的再氧化要广泛得多，多达99%的硫酸盐因此被回收;在这些环境中，δ O-18（SO 4）相对于δ S-34（SO 4）的增加要快得多。我们推测，亚硫酸盐的再循环在BSR过程中起着生理作用，有助于维持微生物活性，其中电子供体的可用性（e。G.有机质含量低。(C)2013爱思唯尔有限公司保留所有权利。
We present new sulfur and oxygen isotope data in sulfate (delta S-34(SO4) and delta O-18(SO4), respectively), from globally distributed marine and estuary pore fluids. We use this data with a model of the biochemical steps involved in bacterial sulfate reduction (BSR) to explore how the slope on a delta O-18(SO4) vs. delta S-34(SO4) plot relates to the net sulfate reduction rate (nSRR) across a diverse range of natural environments. Our data demonstrate a correlation between the nSRR and the slope of the relative evolution of oxygen and sulfur isotopes (delta O-18(SO4) vs. delta S-34(SO4)) in the residual sulfate pool, such that higher nSRR results in a lower slope (sulfur isotopes increase faster relative to oxygen isotopes). We combine these results with previously published literature data to show that this correlation scales over many orders of magnitude of nSRR. Our model of the mechanism of BSR indicates that the critical parameter for the relative evolution of oxygen and sulfur isotopes in sulfate during BSR in natural environments is the rate of intracellular sulfite oxidation. In environments where sulfate reduction is fast, such as estuaries and marginal marine environments, this sulfite reoxidation is minimal, and the delta O-18(SO4) increases more slowly relative to the delta S-34(SO4). In contrast, in environments where sulfate reduction is very slow, such as deep sea sediments, our model suggests sulfite reoxidation is far more extensive, with as much as 99% of the sulfate being thus recycled; in these environments the delta O-18(SO4) increases much more rapidly relative to the delta S-34(SO4). We speculate that the recycling of sulfite plays a physiological role during BSR, helping maintain microbial activity where the availability of the electron donor (e. g. available organic matter) is low. (C) 2013 Elsevier Ltd. All rights reserved.