Radiocarbon in marine bacteria: Evidence for the ages of assimilated carbon
Radiocarbon in marine bacteria: Evidence for the ages of assimilated carbon
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DOI：
10.4319/lo.1999.44.3.0730
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发表时间：
1999-05-01
影响因子：
4.5
通讯作者：
Chanton, JP
中科院分区：
文献类型：
--
作者：
Cherrier, J;Bauer, JE;Chanton, JP
人们普遍认为，海洋细菌利用不稳定的，最近产生的散装溶解有机物的成分。这一解释主要是基于间接测量使用模型化合物和莱顿衍生的有机物。在这里，我们提出了一个现代和旧的溶解有机碳（DOC）利用海洋细菌的相对比例的评估。从河口（圣罗莎湾，佛罗里达州）和开放的海洋（北太平洋东部）网站收集细菌核酸，并在这两个系统中的核酸碳的天然放射性碳签名进行了测定。细菌核酸从圣罗莎声音显着丰富的放射性碳相对于散装DOC和大气中的二氧化碳在采样时的放射性碳签名相似，表明这些细菌完全同化的河口散装狗的现代成分。与此相反，从海洋站点的细菌核酸富集在C-14相对于散装DOC，但耗尽在C-14相对于现代表面溶解无机碳（DIC）和悬浮颗粒有机碳（POCsusp）。这表明，开放的海洋细菌同化现代和旧的组成部分狗。在这两个位点上的核酸的不同放射性碳特征（即，+120 +/- 17%河口与-34 +/- 24%海洋）表明，细菌生物标志物的天然C-14丰度测量是研究不同水生系统中微生物群落碳循环的有力工具。
It is generally accepted that marine bacteria utilize labile, recently produced components of bulk dissolved organic matter. This interpretation is based largely on indirect measurements using model compounds and plankton-derived organic matter. Here, we present an assessment of the relative proportions of modem and older dissolved organic carbon (DOC) utilized by marine bacteria. Bacterial nucleic acids were collected from both estuarine (Santa Rosa Sound, FL) and open-ocean (eastern North Pacific) sites, and the natural radiocarbon signatures of the nucleic acid carbon in both systems were determined. Bacterial nucleic acids from Santa Rosa Sound were significantly enriched in radiocarbon with respect to the bulk DOC and were similar to the radiocarbon signature of atmospheric CO2 at the time of sampling, indicating that these bacteria exclusively assimilate a modem component of the estuarine bulk DOG. In contrast, bacterial nucleic acids from the oceanic site were enriched in C-14 relative to the bulk DOC but depleted in C-14 with respect to modem surface dissolved inorganic carbon (DIC) and suspended particulate organic carbon (POCsusp). This suggests that open-ocean bacteria assimilate both modem and older components of DOG. The distinct radiocarbon signatures of the nucleic acids at these two sites (i.e., +120 +/- 17% estuarine vs. -34 +/- 24% oceanic) demonstrate that natural C-14 abundance measurements of bacterial biomarkers are a powerful tool for investigations of carbon cycling through microbial communities in different aquatic systems.