title: Spatiotemporal distribution of the magnetotactic multicellular prokaryote Candidatus Magnetoglobus multicellularis in a Brazilian hypersaline lagoon and in microcosms.
abstract: Candidatus Magnetoglobus multicellularis is an unusual morphotype of magnetotactic prokaryotes. These microorganisms are composed of a spherical assemblage of gram-negative prokaryotic cells capable of swimming as a unit aligned along a magnetic field. While they occur in many aquatic habitats around the world, high numbers of Ca. M. multicellularis have been detected in Araruama Lagoon, a large hypersaline lagoon near the city of Rio de Janeiro, in Brazil. Here, we report on the spatiotemporal distribution of one such population in sediments of Araruama Lagoon, including its annual distribution and its abundance compared with the total bacterial community. In microcosm experiments, Ca. M. multicellularis was unable to survive for more than 45 days: the population density gradually decreased coinciding with a shift to the upper layers of the sediment. Nonetheless, Ca. M. multicellularis was detected throughout the year in all sites studied. Changes in the population density seemed to be related to the input of organic matter as well as to salinity. The population density of Ca. M. multicellularis did not correlate with the total bacterial counts; instead, changes in the microbial community structure altered their counts in the environment.
authors.affiliation: Institute of Microbiology Prof. Paulo de Góes, Federal University of Rio de Janeiro, Center of Health Sciences, Rio de Janeiro, Brazil. jlmartins@inmetro.gov.br
authors.forename: Juliana L
authors.initials: JL
authors.lastname: Martins
authors.forename: Thais S
authors.initials: TS
authors.lastname: Silveira
authors.forename: Fernanda
authors.initials: F
authors.lastname: Abreu
authors.forename: Fernando P
authors.initials: FP
authors.lastname: de Almeida
authors.forename: Alexandre S
authors.initials: AS
authors.lastname: Rosado
authors.forename: Ulysses
authors.initials: U
authors.lastname: Lins
mesh_terms: D001938:Brazil; D020564:Deltaproteobacteria / Q000254:growth & development* / Q000302:isolation & purification / Q000648:ultrastructure; D060526:Magnetic Fields; D054712:Salinity; D014871:Water Microbiology