Magnetotactic bacteria are microorganisms that present intracellular chains of magnetic nanoparticles, the magnetosome chain. A challenge in the study of magnetotactic bacteria is the measurement of the magnetic moment associated with the magnetosome chain. Several techniques have been used to estimate the average magnetic moment of a population of magnetotactic bacteria, and others permit the measurement of the magnetic moment of individual bacteria. The U-turn technique allows the measurement of the individual magnetic moment and other parameters associated with the movement and magnetotaxis, such as the velocity and the orientation angle of the trajectory relative to the applied magnetic field. The aim of the present paper is to use the U-turn technique in a population of uncultured magnetotactic cocci to measure the magnetic moment, the volume, orientation angle and velocity for the same individuals. Our results showed that the magnetic moment is distributed in a log-normal distribution, with a mean value of 8.2 × 10–15 Am2 and median of 5.4 × 10–15 Am2. An estimate of the average magnetic moment using the average value of the orientation cosine produces a value similar to the median of the distribution and to the average magnetic moment obtained using transmission electron microscopy. A strong positive correlation is observed between the magnetic moment and the volume. There is no correlation between the magnetic moment and the orientation cosine and between the magnetic moment and the velocity. Those null correlations can be explained by our current understanding of magnetotaxis.
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Abreu F, Acosta-Avalos D (2018) Biology and physics of magnetotactic bacteria. In: Barakat KM (ed) Bacteriology, 1st edn. IntechOpen, London. DOI: 10.5772/intechopen.79965.
Araujo ACV, Morillo V, Cypriano J et al (2016) Combined genomic and structural analyses of a cultured magnetotactic bacterium reveals its niche adaptation to a dynamic environment. BEM Genom 17(Suppl 8):726
Chen H, Zhang SD, Chen L, Cai Y, Zhang WJ, Song T, Wu LF (2018) Efficient genome editing of Magnetospirillum magneticum AMB-1 by CRISPR-Cas9 system for analyzing magnetotactic behavior. Front Microbiol 9:1569
De Melo RD, Acosta-Avalos D (2017) The swimming polarity of multicellular magnetotactic prokaryotes can change during an isolation process employing magnets: evidence of a relation between swimming polarity and magnetic moment intensity. Eur Biophys J 46:533–539
Esquivel DMS, Lins de Barros HGP (1986) Motion of magnetotactic microorganisms. J Exp Biol 121:153–163
Felfoul O, Mohammadi M, Taherkhani S et al (2016) Magneto-aerotactic bacteria deliver drug-containing nanoliposomes to tumour hypoxic regions. Nat Nanotechnol 11:941–947
Frankel RB, Blakemore RP (1980) Navigational compass in magnetic bacteria. J Magn Magn Mater 15–18:1562–1564
Kalmijn AJ (1981) Biophysics of geomagnetic field detection. IEEE Trans Magn 17:1113–1124
Lins U, Freitas F, Keim CN, de Barros HL, Esquivel DMS, Farina M (2003) Simple homemade apparatus for harvesting uncultured magnetotactic microorganisms. Br J Microbiol 34:111–116
Nogueira FS, de Barros HGPL (1995) Study of the motion of magnetotactic bacteria. Eur Biophys J 24:13–21
Perantoni M, Esquivel DMS, Wajnberg E, Acosta-Avalos D, Cernicchiaro G, de Barros HL (2009) Magnetic properties of the microorganism Candidatus Magnetoglobus multicellularis. Naturwissenschaften 96:685–690
Petersen N, Weiss DG, Vali H (1989) Magnetic bacteria in lake sediments. In: Lowes F (ed) Geomagnetism and Paleomagnetism. Kluwer, Amsterdan-Berlin, pp 231-241. DOI: 10.1007/978-94-009-0905-2_17
Pichel MP, Hageman TAG, Khalil ISM, Manz A, Abelmann L (2018) Magnetic response of Magnetospirillum gryphiswaldense observed inside a microfluidic channel. J Magn Magn Mater 460:340–353
Rosenblatt C, de Araujo FFT, Frankel RB (1982) Birefringence determination of magnetic moments of magnetotactic bacteria. Biophys J 40:83–85
Rosenblatt C, de Araujo FFT, Frankel RB (1982) Light scattering determination of magnetic moments of magnetotactic bacteria. J Appl Phys 53:2727–2729
Wajnberg E, de Souza LHS, de Barros HGPL, Esquivel DMS (1986) A study of magnetic properties of magnetotactic bacteria. Biophys J 50:451–455
Zahn C, Keller S, Toro-Nahuelpan M, Dorscht P, Gross W, Laumann M, Gekle S, Zimmermann W, Schuler D, Kress H (2017) Measurement of the magnetic moment of single Magnetospirillum gryphiswaldense cells by magnetic tweezers. Scientific Reports 7:3558
Zhang WY, Zhou K, Pan HM, Yue HD, Jiang M, Xiao T, Wu LF (2012) Two genera of magnetococci with bean-like morphology from intertidal sediments of the Yellow Sea, China. Appl Environ Microbiol 78:5606–5611
Cassia Picanço Conceição, Jayane Julia Pereira da Silva, Kaio José Monteiro São Paulo Aguiar and Marciano de Lima Medeiros thank the financial support for the 3er EAFEX (Escola Avançada de Física Experimental do CBPF) done in February 2018. We thank also the support of LABNANO-CBPF for SEM. F. Abreu acknowledges support from FAPERJ, Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) and thanks the microscopy facilities CENABIO-UFRJ and UniMicro-UFRJ.
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Acosta-Avalos, D., de Figueiredo, A.C., Conceição, C.P. et al. U-turn trajectories of magnetotactic cocci allow the study of the correlation between their magnetic moment, volume and velocity. Eur Biophys J 48, 513–521 (2019). https://doi.org/10.1007/s00249-019-01375-2
- Magnetotactic bacteria
- Magnetic moment
- Bacterial velocity