STIMULATION OF Escherichia coli DIVISION BY LOW‐INTENSITY MONOCHROMATIC VISIBLE LIGHT

Abstract

Abstract— Bacterial suspensions in a phosphate buffer were irradiated at 364, 404, 434, 454, 484, 520, 560. 570, 599, 619, 630, 633, 640, 693, 730 and 750 nm, incubated in Hottinguer broth, and assayed for viability by the standard surface plating technique. When irradiated at 404, 454, 560, 619, and 750 nm, the cells started dividing more rapidly, the growth stimulation effect reaching170–180% 60 min after irradiation. The shape of the action spectrum and the reduced‐minus‐oxidized difference spectrum of the bacterial suspensions suggest that respiratory chain components of the bacterium such as dehydrogenases and cyt d might be the photoacceptors involved. The growth stimulation effect is believed to be due to the ability of the irradiation‐activated respiratory chain to produce the necessary pH gradient more rapidly, thus enabling the cells to start dividing earlier.

The Effects of Daily Irradiation with Polychromatic Visible Polarized Light on Human Lymphocyte Populations

“…40,41 At a certain spectral range, the absorption of visible light results in an increase in intracellular pH, which then leads to stimulation of mitosis. 42 In our laboratory, after irradiation of distilled water with polychromatic visible polarized light from the Photomedi device, the pH of the water increased from 6.84 to 8.30 in 39 h (unpublished data). Perhaps this occurred because the water molecules ionized to form hydrated electrons due to the irradiation.…”

Effects on the mitosis of normal and tumor cells induced by light treatment of different wavelengths

“…It was found that the action spectra of visible and near-infrared light of various growth-stimulating and damaging effects of certain organisms correspond to the absorption bands of respiratory chain components such as the flavins and the cytochromes [3][4][5]22,23]. It was reported that the absorption of light in this spectral range resulted in an increase of the intracellular pH which stimulated the mitosis [24]. Support in favor of the assumption that the primary photo-acceptors are pigments located in the mitochondrion is provided by the observation of enhanced ATP-synthesis in isolated mitochondria at appropriate wavelengths [7,[24][25][26].…”

“…It was reported that the absorption of light in this spectral range resulted in an increase of the intracellular pH which stimulated the mitosis [24]. Support in favor of the assumption that the primary photo-acceptors are pigments located in the mitochondrion is provided by the observation of enhanced ATP-synthesis in isolated mitochondria at appropriate wavelengths [7,[24][25][26]. As the spectrum [5][6][7]27] of cytochrome a/a3 or cytochrome oxidase extends with a weak tail to the near-infrared spectral range between ‫ס‬ 700 nm and ‫ס‬ 900 nm, these pigments seem to be the primary photo-acceptors of the experiments performed.…”

Photobiostimulation effects caused by a high power IR laser with λ=850nm in wheat (Triticum aestivum L)

“…In most of the cases He-Ne lasers with λ=632.8 nm are the grounds of these studies. In some cases they vary the wavelength to obtain a λ=650 nm or for using near infrared radiation [1][2][3][4][5][6].…”

“…Up today He-Ne lasers with λ=632.8 nm, semiconductors lasers, and LED´s in the range of l=600-1000 nm are used. It is important to stay that we only irradiate one time and the next reactions occur in the dark [5].…”