@article{141,
  author = {J.-P. Bellenger and Y. Xu and X. Zhang and F.M.M. Morel and },
  title = {Possible contribution of alternative nitrogenases to nitrogen fixation by asymbiotic N2-fixing bacteria in soils},
  abstract = {The relative contributions of the alternative (V- and Fe-only) and canonical (Mo-) nitrogenases to N2 fixation in natural environments are still largely unknown. Here we combine chemical and molecular approaches to examine their role in terrestrial ecosystems. Pure-culture studies show that while the R ratio (defined as R=acetylene reduction rate/N2 fixation rate by nitrogenase) is highly variable, low R ratios (0.5\<R\<2) are usually an indication of alternative nitrogenase activity. Microcosm experiments with temperate soils showed low R ratios and a large increase in N2 fixation rates in response to vanadium amendments, indicating V-nitrogenase activity. Using RT-PCR, we were able to demonstrate expression of the V-nitrogenase, together with the Mo-nitrogenase, in these soils. An analysis of published R ratios showed that the contribution of alternative nitrogenases to asymbiotic N2 fixation in soils may be more prevalent than previously recognized. {\textcopyright} 2013 Elsevier Ltd.},
  year = {2014},
  journal = {Soil Biology and Biochemistry},
  volume = {69},
  pages = {413-420},
  url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84890883796\&doi=10.1016\%2fj.soilbio.2013.11.015\&partnerID=40\&md5=b185c878d52f6f0e46cd6bb296a83631},
  doi = {10.1016/j.soilbio.2013.11.015},
}