Association of magnetotactic multicellular prokaryotes with Pseudoalteromonas species in a natural lagoon environment

• Published in: Antonie van Leeuwenhoek Vol. 111; no. 11; pp. 2213 - 2223
• Main Authors: Leão, Pedro, Gueiros-Filho, Frederico J., Bazylinski, Dennis A., Lins, Ulysses, Abreu, Fernanda
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01-11-2018; Springer Nature B.V
• Subjects: Bacteria; Biomedical and Life Sciences; Cell culture; Freshwater environments; Lagoons; Life Sciences; Medical Microbiology; Microbiology; Microorganisms; Original Paper; Parasites; Plant Sciences; Prokaryotes; Pseudoalteromonas; Soil Science & Conservation; Species; Water analysis; Water sampling; Microbial association; Magnetosome; Magnetotactic bacteria; Magnetotaxis; Magnetotactic multicellular prokaryotes
• ISSN: 0003-6072; 1572-9699
• DOI: 10.1007/s10482-018-1113-x

Magnetotactic bacteria, for the most part, are free-living, motile, unicellular prokaryotes that inhabit almost all marine and freshwater environments. One notable exception to the unicellular mode, however, are the magnetotactic multicellular prokaryotes. These morphologically unique prokaryotes (e.g.,
Candidatus
Magnetoglobus multicellularis) are motile aggregates of 20–40 genetically identical, Gram-negative cells organised as a sphere (or ovoid in shape) and only motile as a unit. No specific close physical association between magnetotactic bacteria and non-magnetotactic microorganisms has ever been reported. Here, using culture-independent approaches, we show an unusual association between the spherical magnetotactic multicellular prokaryote
Ca.
Magnetoglobus multicellularis and
Pseudoalteromonas
species in environmental sediment and water samples collected from the Araruama Lagoon in Brazil. Cells of
Pseudoalteromonas
species were observed to be physically attached to the surface and, notably, even in the intercellular space of these spherical magnetotactic multicellular prokaryotes. An attempt to correlate the frequency of association between
Pseudoalteromonas
and magnetotactic multicellular prokaryotes with sediment depth was made but only a slight decrease in the number of
Pseudoalteromonas
cells per magnetotactic multicellular prokaryote was observed with increasing depth. Similar observations were made with magnetotactic multicellular prokaryotes from another Brazilian Lagoon (Rodrigo de Freitas) and the putative symbiont/parasite was detected. Although our results suggest some sort of specificity in the relationship between these prokaryotes, the precise nature of this association remains unclear.