title: Isolation, cultivation and genomic analysis of magnetosome biomineralization genes of a new genus of South-seeking magnetotactic cocci within the Alphaproteobacteria.
abstract: Although magnetotactic bacteria (MTB) are ubiquitous in aquatic habitats, they are still considered fastidious microorganisms with regard to growth and cultivation with only a relatively low number of axenic cultures available to date. Here, we report the first axenic culture of an MTB isolated in the Southern Hemisphere (Itaipu Lagoon in Rio de Janeiro, Brazil). Cells of this new isolate are coccoid to ovoid in morphology and grow microaerophilically in semi-solid medium containing an oxygen concentration ([O2]) gradient either under chemoorganoheterotrophic or chemolithoautotrophic conditions. Each cell contains a single chain of approximately 10 elongated cuboctahedral magnetite (Fe3O4) magnetosomes. Phylogenetic analysis based on the 16S rRNA gene sequence shows that the coccoid MTB isolated in this study represents a new genus in the Alphaproteobacteria; the name Magnetofaba australis strain IT-1 is proposed. Preliminary genomic data obtained by pyrosequencing shows that M. australis strain IT-1 contains a genomic region with genes involved in biomineralization similar to those found in the most closely related magnetotactic cocci Magnetococcus marinus strain MC-1. However, organization of the magnetosome genes differs from M. marinus.
authors.affiliation: Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro Rio de Janeiro, Brazil.
authors.forename: Viviana
authors.initials: V
authors.lastname: Morillo
authors.affiliation: Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro Rio de Janeiro, Brazil.
authors.forename: Fernanda
authors.initials: F
authors.lastname: Abreu
authors.affiliation: Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro Rio de Janeiro, Brazil.
authors.forename: Ana C
authors.initials: AC
authors.lastname: Araujo
authors.affiliation: Laboratório Nacional de Computação Científica, Departamento de Matemática Aplicada e Computacional Petrópolis, Brazil.
authors.forename: Luiz G P
authors.initials: LG
authors.lastname: de Almeida
authors.affiliation: Instituto de Biologia, Universidade Federal do Rio de Janeiro Rio de Janeiro, Brazil.
authors.forename: Alex
authors.initials: A
authors.lastname: Enrich-Prast
authors.affiliation: Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro Rio de Janeiro, Brazil.
authors.forename: Marcos
authors.initials: M
authors.lastname: Farina
authors.affiliation: Laboratório Nacional de Computação Científica, Departamento de Matemática Aplicada e Computacional Petrópolis, Brazil.
authors.forename: Ana T R
authors.initials: AT
authors.lastname: de Vasconcelos
authors.affiliation: School of Life Sciences, University of Nevada at Las Vegas Las Vegas, NV, USA.
authors.forename: Dennis A
authors.initials: DA
authors.lastname: Bazylinski
authors.affiliation: Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro Rio de Janeiro, Brazil.
authors.forename: Ulysses
authors.initials: U
authors.lastname: Lins
keywords: Magnetofaba australis strain IT-1; South-seeking magnetotactic bacteria; biomineralization genes; magnetite; magnetosome