Evaluation of the 18O-H2O incubation method for measurement of soil microbial carbon use efficiency
Evaluation of the 18O-H2O incubation method for measurement of soil microbial carbon use efficiency
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DOI：
10.1016/j.soilbio.2020.107802
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发表时间：
2020-06
影响因子：
9.7
通讯作者：
Lingrui Qu;Chao Wang;E. Bai
中科院分区：
文献类型：
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作者：
Lingrui Qu;Chao Wang;E. Bai
18O标记水法已被广泛用于估计微生物碳利用效率(CUE)。然而，这种方法假设微生物DNA合成中的氧气是100%来自水，而这一假设尚未得到验证。我们使用18O标记的葡萄糖和18O标记的水来测试这一假设，以了解它们在微生物DNA合成中对氧的贡献。结果表明，微生物合成DNA所需的葡萄糖-氧气低于8.3%，水氧大于91.7%。~(18)O标记水法在土壤水中~(18)O含量较低的情况下是可靠的。我们建议使用一个修正系数(即本研究中的1.1)来说明从水以外的其他来源进入DNA的氧。
The18O-labelled water approach has been widely used to estimate microbial carbon use efficiency (CUE). However, this approach assumes that oxygen in microbial DNA synthesis is 100% from water while this assumption has not been tested. We tested this assumption using18O-labelled glucose and18O-labelled water to see their contributions to the oxygen in microbial DNA synthesis. Results showed microbes used less than 8.3% glucose-oxygen and more than 91.7% water-oxygen for their DNA synthesis. The18O-labelled water method for estimation of CUE has proven to be reliable under low enrichment of18O in soil water. We suggest to use a correction factor (i.e., 1.1 in this study) to account for oxygen incorporated into DNA from other sources than water.