Application of stable‐isotope labelling techniques for the detection of active diazotrophs

In the above article, it came to the authors' attention that the 15N-N2 gas used only for the ‘Comparison of 15N2-tracer assay with the acetylene reduction assay’ (data in Figure 1A,C) contained traces of 15N-labeled ammonia gas (155.16 ppm). The authors repeated the experiment with 15N-N2 gas free of such contamination and observed the same patterns, as shown in the figure below (Figure 1A,C); they detected incorporation of 15N with the 15N2-tracer assay when nitrogenase activity was not detectable with the acetylene reduction assay. Thus, this repeat confirmed that the application of the 15N2-tracer assay had a higher sensitivity than the acetylene reduction assay. The updated results do not change the implications or interpretations of the study. The authors thank Gaute Lavik from the Max Planck Institute for Marine Microbiology, Bremen, Germany, for analyzing the 15N-N2 gas samples.