AUTHOR=Sepp Siim-Kaarel , Vasar Martti , Davison John , Oja Jane , Anslan Sten , Al-Quraishy Saleh , Bahram Mohammad , Bueno C. Guillermo , Cantero Juan José , Fabiano Ezequiel Chimbioputo , Decocq Guillaume , Drenkhan Rein , Fraser Lauchlan , Garibay Oriel Roberto , Hiiesalu Inga , Koorem Kadri , Kõljalg Urmas , Moora Mari , Mucina Ladislav , Öpik Maarja , Põlme Sergei , Pärtel Meelis , Phosri Cherdchai , Semchenko Marina , Vahter Tanel , Vasco Palacios Aida M. , Tedersoo Leho , Zobel Martin TITLE=Global diversity and distribution of nitrogen-fixing bacteria in the soil JOURNAL=Frontiers in Plant Science VOLUME=14 YEAR=2023 URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2023.1100235 DOI=10.3389/fpls.2023.1100235 ISSN=1664-462X ABSTRACT=

Our knowledge of microbial biogeography has advanced in recent years, yet we lack knowledge of the global diversity of some important functional groups. Here, we used environmental DNA from 327 globally collected soil samples to investigate the biodiversity patterns of nitrogen-fixing bacteria by focusing on the nifH gene but also amplifying the general prokaryotic 16S SSU region. Globally, N-fixing prokaryotic communities are driven mainly by climatic conditions, with most groups being positively correlated with stable hot or seasonally humid climates. Among soil parameters, pH, but also soil N content were most often shown to correlate with the diversity of N-fixer groups. However, specific groups of N-fixing prokaryotes show contrasting responses to the same variables, notably in Cyanobacteria that were negatively correlated with stable hot climates, and showed a U-shaped correlation with soil pH, contrary to other N-fixers. Also, the non-N-fixing prokaryotic community composition was differentially correlated with the diversity and abundance of N-fixer groups, showing the often-neglected impact of biotic interactions among bacteria.