The oil-contaminated soil diazotroph Azoarcus olearius DQS-4T is genetically and phenotypically similar to the model grass endophyte Azoarcus sp. BH72

Helisson Faoro, Rodrigo Rene Menegazzo, Federico Battistoni, Prasad Gyaneshwar, Fernanda P. do Amaral, Cecilia Taulé, Sydnee Rausch, Patricia Gonçalves Galvão, Cecilia de los Santos, Shubhajit Mitra, Gabriela Heijo, Shih Yi Sheu, Wen Ming Chen, Cintia Mareque, Michelle Zibetti Tadra-Sfeir, J. Ivo Baldani, Marta Maluk, Ana Paula Guimarães, Gary Stacey, Emanuel M. de SouzaFabio O. Pedrosa, Leonardo Magalhães Cruz, Euan K. James

Research output: Contribution to journalArticlepeer-review

25 Scopus citations


The genome of Azoarcus olearius DQS-4T, a N2-fixing Betaproteobacterium isolated from oil-contaminated soil in Taiwan, was sequenced and compared with other Azoarcus strains. The genome sequence showed high synteny with Azoarcus sp. BH72, a model endophytic diazotroph, but low synteny with five non-plant-associated strains (Azoarcus CIB, Azoarcus EBN1, Azoarcus KH32C, A. toluclasticus MF63T and Azoarcus PA01). Average Nucleotide Identity (ANI) revealed that DQS-4T shares 98.98% identity with Azoarcus BH72, which should now be included in the species A. olearius. The genome of DQS-4T contained several genes related to plant colonization and plant growth promotion, such as nitrogen fixation, plant adhesion and root surface colonization. In accordance with the presence of these genes, DQS-4T colonized rice (Oryza sativa) and Setaria viridis, where it was observed within the intercellular spaces and aerenchyma mainly of the roots. Although they promote the growth of grasses, the mechanism(s) of plant growth promotion by A. olearius strains is unknown, as the genomes of DQS-4T and BH72 do not contain genes for indole acetic acid (IAA) synthesis nor phosphate solubilization. In spite of its original source, both the genome and behaviour of DQS-4T suggest that it has the capacity to be an endophytic, nitrogen-fixing plant growth-promoting bacterium.

Original languageEnglish (US)
Pages (from-to)223-238
Number of pages16
JournalEnvironmental Microbiology Reports
Issue number3
StatePublished - Jun 2017
Externally publishedYes

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Agricultural and Biological Sciences (miscellaneous)


Dive into the research topics of 'The oil-contaminated soil diazotroph Azoarcus olearius DQS-4<sup>T</sup> is genetically and phenotypically similar to the model grass endophyte Azoarcus sp. BH72'. Together they form a unique fingerprint.

Cite this