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Magnetic field is the dominant factor to induce the response of Streptomyces avermitilis in altered gravity simulated by diamagnetic levitation.

Liu M, Gao H, Shang P, Zhou X, Ashforth E, Zhuo Y, Chen D, Ren B, Liu Z, Zhang L - PLoS ONE (2011)

Bottom Line: The results showed that diamagnetic levitation could induce a physiological response in S. avermitilis.The difference between 1 g* and the control group grown without the strong magnetic field (1 g), showed that the magnetic field was a more dominant factor influencing changes in morphology and secondary metabolite production, than altered gravity.We have discovered that magnetic field, rather than altered gravity, is the dominant factor in altered gravity simulated by diamagnetic levitation, therefore care should to be taken in the interpretation of results when using diamagnetic levitation as a technique to simulate altered gravity.

View Article: PubMed Central - PubMed

Affiliation: Chinese Academy of Sciences Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Beijing, People's Republic of China.

ABSTRACT

Background: Diamagnetic levitation is a technique that uses a strong, spatially varying magnetic field to simulate an altered gravity environment, as in space. In this study, using Streptomyces avermitilis as the test organism, we investigate whether changes in magnetic field and altered gravity induce changes in morphology and secondary metabolism. We find that a strong magnetic field (12T) inhibit the morphological development of S. avermitilis in solid culture, and increase the production of secondary metabolites.

Methodology/principal findings: S. avermitilis on solid medium was levitated at 0 g*, 1 g* and 2 g* in an altered gravity environment simulated by diamagnetic levitation and under a strong magnetic field, denoted by the asterix. The morphology was obtained by electromicroscopy. The production of the secondary metabolite, avermectin, was determined by OD(245 nm). The results showed that diamagnetic levitation could induce a physiological response in S. avermitilis. The difference between 1 g* and the control group grown without the strong magnetic field (1 g), showed that the magnetic field was a more dominant factor influencing changes in morphology and secondary metabolite production, than altered gravity.

Conclusion/significance: We have discovered that magnetic field, rather than altered gravity, is the dominant factor in altered gravity simulated by diamagnetic levitation, therefore care should to be taken in the interpretation of results when using diamagnetic levitation as a technique to simulate altered gravity. Hence, these results are significant, and timely to researchers considering the use of diamagnetic levitation to explore effects of weightlessness on living organisms and on physical phenomena.

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Related in: MedlinePlus

Photograph of the diamagnetic levitation apparatus.The apparatus is located in the Key Laboratory for Space Biosciences & Biotechnology of the Northwestern Polytechnical University, China.
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pone-0024697-g001: Photograph of the diamagnetic levitation apparatus.The apparatus is located in the Key Laboratory for Space Biosciences & Biotechnology of the Northwestern Polytechnical University, China.

Mentions: The experiments were carried out using a ground-based bioreactor within a large gradient superconducting magnet, developed by the Northwestern Polytechnical University, China (Fig. 1). The magnet had a 51-mm vertical bore and produced a 16.12-T maximum field. The experimental samples were viewed with a subminiature CCD camera (QN42HL, EMLO, USA), and images were recorded with a computer. The temperature of the chambers containing the samples was kept at 28°C using a digital water-circulating bath, with variation over time of less than 0.5°C. A water jacket was installed in the bore to guarantee minor temperature fluctuation, and brass was chosen for the wall of the water jacket to allow the temperature control system to continue to work at a high magnet field. The temperature-controlled chamber consisted of a tube, inserted into the magnet bore, with three slots, one at each of the 0 g*, 1 g* and 2 g* gravitational positions (the asterisk on the label indicated the sample was in a strong magnetic field). The 1 g* sample was located at the centre of the coil, since at this point, the sample was not exposed to any change in normal gravitational force; the 0 g* sample was located above the center, where the magnetic force balanced the gravitational force; and the 2 g* sample was located below the 1 g* position, where gravity and the magnetic force were additive [15]. A control‘1 g’ sample was also included, which is grown outside of the magnet and compared to the 1 g* sample. This enabled us to distinguish experimentally between the effects of magnetic forces and that of altered gravity.


Magnetic field is the dominant factor to induce the response of Streptomyces avermitilis in altered gravity simulated by diamagnetic levitation.

Liu M, Gao H, Shang P, Zhou X, Ashforth E, Zhuo Y, Chen D, Ren B, Liu Z, Zhang L - PLoS ONE (2011)

Photograph of the diamagnetic levitation apparatus.The apparatus is located in the Key Laboratory for Space Biosciences & Biotechnology of the Northwestern Polytechnical University, China.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3198441&req=5

pone-0024697-g001: Photograph of the diamagnetic levitation apparatus.The apparatus is located in the Key Laboratory for Space Biosciences & Biotechnology of the Northwestern Polytechnical University, China.
Mentions: The experiments were carried out using a ground-based bioreactor within a large gradient superconducting magnet, developed by the Northwestern Polytechnical University, China (Fig. 1). The magnet had a 51-mm vertical bore and produced a 16.12-T maximum field. The experimental samples were viewed with a subminiature CCD camera (QN42HL, EMLO, USA), and images were recorded with a computer. The temperature of the chambers containing the samples was kept at 28°C using a digital water-circulating bath, with variation over time of less than 0.5°C. A water jacket was installed in the bore to guarantee minor temperature fluctuation, and brass was chosen for the wall of the water jacket to allow the temperature control system to continue to work at a high magnet field. The temperature-controlled chamber consisted of a tube, inserted into the magnet bore, with three slots, one at each of the 0 g*, 1 g* and 2 g* gravitational positions (the asterisk on the label indicated the sample was in a strong magnetic field). The 1 g* sample was located at the centre of the coil, since at this point, the sample was not exposed to any change in normal gravitational force; the 0 g* sample was located above the center, where the magnetic force balanced the gravitational force; and the 2 g* sample was located below the 1 g* position, where gravity and the magnetic force were additive [15]. A control‘1 g’ sample was also included, which is grown outside of the magnet and compared to the 1 g* sample. This enabled us to distinguish experimentally between the effects of magnetic forces and that of altered gravity.

Bottom Line: The results showed that diamagnetic levitation could induce a physiological response in S. avermitilis.The difference between 1 g* and the control group grown without the strong magnetic field (1 g), showed that the magnetic field was a more dominant factor influencing changes in morphology and secondary metabolite production, than altered gravity.We have discovered that magnetic field, rather than altered gravity, is the dominant factor in altered gravity simulated by diamagnetic levitation, therefore care should to be taken in the interpretation of results when using diamagnetic levitation as a technique to simulate altered gravity.

View Article: PubMed Central - PubMed

Affiliation: Chinese Academy of Sciences Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Beijing, People's Republic of China.

ABSTRACT

Background: Diamagnetic levitation is a technique that uses a strong, spatially varying magnetic field to simulate an altered gravity environment, as in space. In this study, using Streptomyces avermitilis as the test organism, we investigate whether changes in magnetic field and altered gravity induce changes in morphology and secondary metabolism. We find that a strong magnetic field (12T) inhibit the morphological development of S. avermitilis in solid culture, and increase the production of secondary metabolites.

Methodology/principal findings: S. avermitilis on solid medium was levitated at 0 g*, 1 g* and 2 g* in an altered gravity environment simulated by diamagnetic levitation and under a strong magnetic field, denoted by the asterix. The morphology was obtained by electromicroscopy. The production of the secondary metabolite, avermectin, was determined by OD(245 nm). The results showed that diamagnetic levitation could induce a physiological response in S. avermitilis. The difference between 1 g* and the control group grown without the strong magnetic field (1 g), showed that the magnetic field was a more dominant factor influencing changes in morphology and secondary metabolite production, than altered gravity.

Conclusion/significance: We have discovered that magnetic field, rather than altered gravity, is the dominant factor in altered gravity simulated by diamagnetic levitation, therefore care should to be taken in the interpretation of results when using diamagnetic levitation as a technique to simulate altered gravity. Hence, these results are significant, and timely to researchers considering the use of diamagnetic levitation to explore effects of weightlessness on living organisms and on physical phenomena.

Show MeSH
Related in: MedlinePlus