Metabolic effects of static magnetic fields on Streptococcus Pyogenes
ABSTRACT This study aimed to develop a simple experimental system utilising bacterial cells to investigate the dose responses resulting from exposures to static magnetic flux densities ranging from 0.05 to 0.5 T on viability, bacterial metabolism and levels of DNA damage in Streptococcus pyogenes. Exposure of S. pyogenes to a field of 0.3 T at 24 degrees C under anaerobic conditions resulted in a significant (P < 0.05) decrease in growth rate, with an increased mean generation time of 199 +/- 6 min compared to the control cells at 165 +/- 6 min (P < 0.05). Conversely, exposure to magnetic fields of 0.5 T significantly accelerated the growth rate at 24 degrees C compared to control cells, with a decreased mean generation time of 147 +/- 4 min (P < 0.05). The patterns of metabolite release from cells incubated in phosphate buffered saline (PBS) at 24 degrees C and exposed to different magnetic flux densities (0.05-0.5 T) were significantly (P < 0.05) altered, compared to non-exposed controls. Concentrations of metabolites, with the exception of aspartic acid (r = 0.44), were not linearly correlated with magnetic flux density, with all other r < 0.20. Instead, "window" effects were observed, with 0.25-0.3 T eliciting the maximal release of the majority of metabolites, suggesting that magnetic fields of these strengths had significant impacts on metabolic homeostasis in S. pyogenes. The exposure of cells to 0.3 T was also found to significantly reduce the yield of 8-hydroxyguanine in extracted DNA compared to controls, suggesting some possible anti-oxidant protection to S. pyogenes at this field strength.
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ABSTRACT: Biological systems can respond to a wide range of static magnetic fields (SMF). Some of these responses seem to be mediated partly through free radical reactions. For example, in magnetic sense and navigation using the geomagnetic field, one of the most promising mechanisms for explaining magnetic compass is "a radical pair mechanism". Biological free radicals are most commonly oxygen or nitrogen based with an unpaired electron, leading to the terms "reactive oxygen species (ROS)" or "reactive nitrogen species (RNS)". When applying SMF to medical treatment, coupling SMF exposure with possible chemotherapy of cancers is a novel fascinating area that SMF could enhance agent-induced ROS production against tumors. In addition, one of the potent mechanisms of SMF effects on hemodynamics and blood pressure has sometimes been linked to nitric oxide pathway. However, health and environmental concerns have been raised because the SMF effects on oxidative stress leading to genetic mutation and apoptosis/necrosis have been found. It seems to take place from free radical generation.Frontiers in Bioscience 02/2008; 13(13):6106-25. DOI:10.2741/3141 · 4.25 Impact Factor
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ABSTRACT: The viability of the microbes Saccharomyces cerevisiae, Bacillus circulans, Escherichia coli, Micrococcus luteus, Pseudomonas fluorescens, Salmonella enteritidis, Serratia marcescens, and Staphylococcus aureus was tested under static magnetic field exposure up to 24 hours in an either homogeneous (159.2 ± 13.4 mT) or 3 types of inhomogeneous static magnetic fields: i) peak-to-peak magnetic flux density 476.7 ± 0.1 mT with a lateral magnetic flux density gradient of 47.7 T/m, or ii) 12.0 ± 0.1 mT with 1.2 T/m, or iii) 2.8 ± 0.1 mT with 0.3 T/m. Even the longest period of exposure failed to produce any effect in the growth of bacteriae that could have been correlated to static magnetic field exposition.Bioelectromagnetics 01/2009; 31(3). DOI:10.1002/bem.20551 · 1.86 Impact Factor
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ABSTRACT: In this study, effect of magnetic field on the activity of activated sludge in wastewater treatment was investigated. During the experiment, biodegradation duration, magnetic density, operating temperature and medium pH value were changed within the ranges from 0 to 60h, 0 to 500.0mT, 10.0 to 50.0 degrees C and 3.0 to 12.0, respectively. These results revealed that activated sludge acclimatization and organic pollutant biodegradation processes under magnetic field were stimulated, resulting in a higher efficiency of wastewater treatment. Biodegradation of organic compounds under magnetic field could reach stable states after 48h. The organic compounds removal rate first roared up and then fell down with the increase of magnetic density of the field, turning at 20.0mT. On account of application of magnetic field, the range of temperature and pH, which is suitable for the growth of microbe, were 20.0-40.0 degrees C and 6.0-10.0, respectively, which were expanded compared with those without the magnetic field.Bioresource Technology 11/2010; 101(22):8535-40. DOI:10.1016/j.biortech.2010.05.094 · 5.04 Impact Factor