| 摘要: |
the 18o-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 using 18o-labelled glucose and 18o-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. the 18o-labelled water method for estimation of cue has proven to be reliable under low enrichment of 18o 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. |
论文
