Combined genomic and structural analyses of a cultured magnetotactic bacterium reveals its niche adaptation to a dynamic environment

Authors

A C. V. Araujo, Universidade Federal do Rio de JaneiroFollow
Viviana K Morillo, University of Nevada, Las VegasFollow
J Cypriano, Universidade Federal do Rio de JaneiroFollow
L CRS Teixeira, Universidade Federal do Rio de Janeiro
P Leão, Universidade Federal do Rio de JaneiroFollow
S Lyra, Universidade Federal do Rio de Janeiro
L G. de Almeida, Laboratório Nacional de Computação Científica
Dennis Bazylinski, University of Nevada, Las VegasFollow
A T.R. de Vasconcelos, Laboratório Nacional de Computação CientíficaFollow
F Abreu, Universidade Federal do Rio de JaneiroFollow
U Lins, Universidade Federal do Rio de JaneiroFollow

Document Type

Article

Publication Date

1-1-2016

Publication Title

BMC Genomics

Volume

17

Issue

1

Abstract

Background: Magnetotactic bacteria (MTB) are a unique group of prokaryotes that have a potentially high impact on global geochemical cycling of significant primary elements because of their metabolic plasticity and the ability to biomineralize iron-rich magnetic particles called magnetosomes. Understanding the genetic composition of the few cultivated MTB along with the unique morphological features of this group of bacteria may provide an important framework for discerning their potential biogeochemical roles in natural environments. Results: Genomic and ultrastructural analyses were combined to characterize the cultivated magnetotactic coccus Magnetofaba australis strain IT-1. Cells of this species synthesize a single chain of elongated, cuboctahedral magnetite (Fe3O4) magnetosomes that cause them to align along magnetic field lines while they swim being propelled by two bundles of flagella at velocities up to 300 μm s-1. High-speed microscopy imaging showed the cells move in a straight line rather than in the helical trajectory described for other magnetotactic cocci. Specific genes within the genome of Mf. australis strain IT-1 suggest the strain is capable of nitrogen fixation, sulfur reduction and oxidation, synthesis of intracellular polyphosphate granules and transporting iron with low and high affinity. Mf. australis strain IT-1 and Magnetococcus marinus strain MC-1 are closely related phylogenetically although similarity values between their homologous proteins are not very high. Conclusion:Mf. australis strain IT-1 inhabits a constantly changing environment and its complete genome sequence reveals a great metabolic plasticity to deal with these changes. Aside from its chemoautotrophic and chemoheterotrophic metabolism, genomic data indicate the cells are capable of nitrogen fixation, possess high and low affinity iron transporters, and might be capable of reducing and oxidizing a number of sulfur compounds. The relatively large number of genes encoding transporters as well as chemotaxis receptors in the genome of Mf. australis strain IT-1 combined with its rapid swimming velocities, indicate that cells respond rapidly to environmental changes.

Language

English

Repository Citation

Araujo, A. C., Morillo, V., Cypriano, J., Teixeira, L. C., Leão, P., Lyra, S., de Almeida, L. G., Bazylinski, D., de Vasconcelos, A. T., Abreu, F., Lins, U. (2016). Combined genomic and structural analyses of a cultured magnetotactic bacterium reveals its niche adaptation to a dynamic environment. BMC Genomics, 17(1),
http://dx.doi.org/10.1186/s12864-016-3064-9