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Abstract

Non-symbiotic are among the most abundant and ubiquitous microbes in bulk soils globally. Despite this, most available genomic resources for are derived from plant-associated strains. We present high-quality draft genomes for 17 and four cultures isolated from bulk semiarid soils in Arizona, USA. The genome sizes range from 5.99 to 10.4 Mbp. Phylogenomic analysis of the 21 genomes indicates they fall into four clades. Two of the clades are nested within the genus. The other two clades were associated with outgroups basal to . All genomes lack genes coding for molybdenum or vanadium nitrogenases, and genes that code for proteins involved in nodulation, suggesting these isolates are free-living, non-symbiotic and do not fix dinitrogen gas. These genomes offer new resources for investigating free-living lineages.

Funding
This study was supported by the:
  • Joint Genome Institute (Award 10.46936/10.25585/60000446)
    • Principal Award Recipient: PaulCarini
  • Division of Integrative Organismal Systems (Award 2141605)
    • Principal Award Recipient: PaulCarini
  • Simons Foundation (Award 929716)
    • Principal Award Recipient: PaulCarini
  • This is an open-access article distributed under the terms of the Creative Commons Attribution License. This article was made open access via a Publish and Read agreement between the Microbiology Society and the corresponding author’s institution.
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/content/journal/acmi/10.1099/acmi.0.000884.v3
2025-02-13
2026-03-08

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