Open AccessGenome-based reclassification of Azospirillum brasilense Sp245 as the type strain of Azospirillum baldaniorum sp. nov
Author(s) -
Natália dos Santos Ferreira,
Fernando Hayashi Sant ́Anna,
Verônica Massena Reis,
Adriana Ambrosini,
Camila Gazolla Volpiano,
Michael Rothballer,
Stefan Schwab,
Valter A. Baura,
Eduardo Balsanelli,
Fábio de Oliveira Pedrosa,
Luciane Maria Pereira Passaglia,
Emanuel Maltempi de Souza,
Anton Hartmann,
Fabricio Cassán,
Jerri Édson Zilli
Publication year - 2020
Publication title -
international journal of systematic and evolutionary microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 173
eISSN - 1466-5034
pISSN - 1466-5026
DOI - 10.1099/ijsem.0.004517
Subject(s) - azospirillum brasilense , biology , housekeeping gene , strain (injury) , microbial inoculant , genome , 16s ribosomal rna , microbiology and biotechnology , botany , bacteria , gene , genetics , anatomy , gene expression
Azospirillum sp. strain Sp245 T , originally identified as belonging to Azospirillum brasilense , is recognized as a plant-growth-promoting rhizobacterium due to its ability to fix atmospheric nitrogen and to produce plant-beneficial compounds. Azospirillum sp. Sp245 T and other related strains were isolated from the root surfaces of different plants in Brazil. Cells are Gram-negative, curved or slightly curved rods, and motile with polar and lateral flagella. Their growth temperature varies between 20 to 38 °C and their carbon source utilization is similar to other Azospirillum species. A preliminary 16S rRNA sequence analysis showed that the new species is closely related to A. brasilense Sp7 T and A. formosense CC-Nfb-7 T . Housekeeping genes revealed that Azospirillum sp. Sp245 T , BR 12001 and Vi22 form a separate cluster from strain A. formosense CC-Nfb-7 T , and a group of strains closely related to A. brasilense Sp7 T . Overall genome relatedness index (OGRI) analyses estimated based on average nucleotide identity (ANI) and digital DNA–DNA hybridization (dDDH) between Azospirillum sp. Sp245 T and its close relatives to other Azospirillum species type strains, such as A. brasilense Sp7 T and A. formosense CC-Nfb-7 T , revealed values lower than the limit of species circumscription. Moreover, core-proteome phylogeny including 1079 common shared proteins showed the independent clusterization of A. brasilense Sp7 T , A. formosense CC-Nfb-7 T and Azospirillum sp. Sp245 T , a finding that was corroborated by the genome clustering of OGRI values and housekeeping phylogenies. The DNA G+C content of the cluster of Sp245 T was 68.4–68.6 %. Based on the phylogenetic, genomic, phenotypical and physiological analysis, we propose that strain Sp245 T together with the strains Vi22 and BR12001 represent a novel species of the genus Azospirillum , for which the name Azospirillum baldaniorum sp. nov. is proposed. The type strain is Sp245 T (=BR 11005 T =IBPPM 219 T ) (GCF_007827915.1, GCF_000237365.1, and GCF_003119195.2).