Taxonomic patterns in the nitrogen assimilation of soil prokaryotes

Environ Microbiol. 2018 Mar;20(3):1112-1119. doi: 10.1111/1462-2920.14051. Epub 2018 Mar 14.

Abstract

Nitrogen (N) is frequently a limiting nutrient in soil; its availability can govern ecosystem functions such as primary production and decomposition. Assimilation of N by microorganisms impacts the availability of N in soil. Despite its established ecological significance, the contributions of microbial taxa to N assimilation are unknown. Here we measure N uptake and use by microbial phylotypes and taxonomic groups within a diverse assemblage of soil microbes through quantitative stable isotope probing (qSIP) with 15 N. Following incubation with 15 NH4+, distinct patterns of 15 N assimilation among taxonomic groups were observed. For instance, glucose addition stimulated 15 N assimilation in most members of Actinobacteria and Proteobacteria but generally decreased 15 N use by Firmicutes and Bacteriodetes. While NH4+ is considered a preferred and universal source of N to prokaryotes, the majority (> 80%) of N assimilation in our soils could be attributed to a handful of active orders. Characterizing N assimilation of taxonomic groups with 15 N qSIP may provide a basis for understanding how microbial community composition influences N availability in the environment.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Actinobacteria / classification
  • Actinobacteria / metabolism*
  • Ammonium Compounds / metabolism*
  • Bacteroidetes / classification
  • Bacteroidetes / metabolism*
  • Ecology
  • Firmicutes / classification
  • Firmicutes / metabolism*
  • Microbiota
  • Nitrogen / analysis*
  • Nitrogen Isotopes / metabolism*
  • Proteobacteria / classification
  • Proteobacteria / metabolism*
  • Soil
  • Soil Microbiology

Substances

  • Ammonium Compounds
  • Nitrogen Isotopes
  • Nitrogen-15
  • Soil
  • Nitrogen