Allison Cockrell - Life in a Microwave: Effects of Microwave Radiation on Thermus sp.

Document created by Allison Cockrell Zugell on May 21, 2015Last modified by Allison Cockrell Zugell on May 21, 2015
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  Publication Details (including relevant citation   information):

  Oral and Poster presentations,   FEMS 2015: 6th Congress of European   Microbiologists,   Maastricht, Netherlands (2015)


  Background:  Biological systems are frequently exposed to microwave radiation.   Many studies have investigated the influence of microwaves on   biological systems, but controversy over methods to distinguish   between thermal and non-thermal microwave effects remains.

  Objectives: To   differentiate between thermal and non-thermal microwave effects   on a physiology of a microorganism, a thermophilic bacterium was   grown in a constant-temperature microwave and was compared to   convection heating under identical conditions. Comparing the   growth properties of a thermophile will reveal non-thermal   microwave effects on cell growth and physiology. Biophysical and   biochemical analysis will demonstrate changes in morphology and   chemical composition arising from microwave exposure.

  Methods: Cell   growth was analyzed by optical density (OD) measurements   (supported by independent quantitative DNA analysis), and cell   morphologies were characterized using electron microscopy imaging   (SEM, TEM), dynamic light scattering (DLS), and atomic force   microscopy (AFM). AFM was also used to probe the biophysical   characteristics of the cells, in conjunction with nano-infrared   spectroscopy (Nano-IR). Attenuated total reflectance infrared   spectroscopy (ATR-IR) and fatty acid methyl ester (FAMEs)   analysis were used to determine biochemical differences between   cells grown in microwave and oven conditions.

  Conclusions:  Thermophilic bacteria were grown in a synthetic microwave such   that thermal effects and microwave effects were distinguishable.   These data demonstrate that there are physiological differences   between cells cultured in a dielectric field and a convection   oven, and that microwaves induce non-thermal changes to the   structure, physiology, and chemical composition of the organism.


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