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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

Effect of magnetic field (A) and gravity (B) on mutation ratios.***P<0.001, **P<0.01, *P<0.05.
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pone-0024697-g003: Effect of magnetic field (A) and gravity (B) on mutation ratios.***P<0.001, **P<0.01, *P<0.05.

Mentions: Significant changes in the avermectin production profile of PE1 were seen after levitation. The strong 12T magnetic field caused the positive mutation ratio to increase from 7.2±0.4% in group 1 g, to 29.6±2.7% in 1 g* (Fig. 3A). The negative mutation ratio increased from 10.1±0.3% in the group 1 g, to 63.2±6.3% in 1 g*, suggesting magnetic field promoted the instability inherent in Streptomyces [16]. An increase in gravitational force (Fig. 3B) was found to cause an increase in the percentage of negative mutants: 51.0±5.3% at 0 g*; 63.2±6.3% at 1 g*; and 66.1±6.3% at 2 g*. The positive mutation ratio remained more stable with an increase in gravitational force: 26.5±2.4% at 0 g*; 29.6±2.7% at 1 g*; and 27.5±2.6% at 2 g*. These results demonstrated that changes in avermectin production could be mainly attributed to the magnetic field rather than altered gravity environment, especially those mutations resulting in positive increases in avermectin production.


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)

Effect of magnetic field (A) and gravity (B) on mutation ratios.***P<0.001, **P<0.01, *P<0.05.
© Copyright Policy
Related In: Results  -  Collection

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

pone-0024697-g003: Effect of magnetic field (A) and gravity (B) on mutation ratios.***P<0.001, **P<0.01, *P<0.05.
Mentions: Significant changes in the avermectin production profile of PE1 were seen after levitation. The strong 12T magnetic field caused the positive mutation ratio to increase from 7.2±0.4% in group 1 g, to 29.6±2.7% in 1 g* (Fig. 3A). The negative mutation ratio increased from 10.1±0.3% in the group 1 g, to 63.2±6.3% in 1 g*, suggesting magnetic field promoted the instability inherent in Streptomyces [16]. An increase in gravitational force (Fig. 3B) was found to cause an increase in the percentage of negative mutants: 51.0±5.3% at 0 g*; 63.2±6.3% at 1 g*; and 66.1±6.3% at 2 g*. The positive mutation ratio remained more stable with an increase in gravitational force: 26.5±2.4% at 0 g*; 29.6±2.7% at 1 g*; and 27.5±2.6% at 2 g*. These results demonstrated that changes in avermectin production could be mainly attributed to the magnetic field rather than altered gravity environment, especially those mutations resulting in positive increases in avermectin production.

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