Study on the biological effect of Tourmaline on the cell membrane of E. coli

The biological effect of tourmaline on the cell membrane of E. coli by microcalorimetry, fluorescence polarization, ion analysis and fourier transform infrared was studied. It was observed that tourmaline of low concentration can promote growth of the bacteria, while tourmaline of high concentration has inhibitory effects on E. coli. Fluorescence polarization has shown a significant decrease in membrane fluidity and the increase of permeability of cell membrane. The ion analysis result suggested that the absorbability of nutrition from the medium becomes easier. Thus, E. coli grew faster in the presence of tourmaline than the native. With high concentration of tourmaline, however, the growth of E. coli was inhibited because the selective barrier of cell membrane for the bacteria was seriously damaged. Besides, changes of the spectral profile of E. coli were observed, which has shown the damages of surface groups on the cell membrane, which is the molecular basis for the biological effect of tourmaline.