The effect of narrow bandwidth infrared radiation on the growth of Escherichia coli

While broad band infrared has a number of biomedical applications, the effects with specific wavelengths on biomolecule remain unclear. In this study, narrow band infrared plasmonic thermal emitters with peak wavelengths from 3.0 to 5.0 mu m were developed to irradiate Escherichia coli (E. coli) cultures for 24 h. It was found that with peak wavelengths at 4.0, 4.5, and 5.0 mu m, they could promote the growth of cells. Systems biology analyses were performed to investigate the underlying molecular mechanisms. Furthermore, specific wavelengths (4.0-5.0 mu m) induced the expression of transporters and enzymes involved in metabolism and respiration, thus stimulating the proliferation of E. coli. (C) 2011 American Institute of Physics. [doi:10.1063/1.3655031]