[Globin coupled sensor and photosensitive signaling network--receptors of monochromatic light in bacteria Escherichia coli cells].

The effect of He-Ne laser radiation in wide range of intensities on E. coli cells division was studied in dependence on dose of light, on time of irradiation as well as on cAMP content in initial bacterial culture. Two maxima in E.coli growth stimulation vs dose or irradiation time curves were observed: first--irradiation time-independent, near 55 J/m2, second--dose-independent, near 100 s. It was proposed that latter maximum reflects kinetic parameters of photosensitive signaling network, and the former one reflects redox state of globin-coupled direct photosensor--EcDOS phosphodiesterase cAMP.

[Effect of He-Ne-laser irradiation on plasmid transformation of Escherichia coli bacteria]. / Vliianie izlucheniia He-Ne-lazera na plazmidnuiu transformatsiiu bakterii Escherichia coli.

The influence of the of radiation a He-Ne laser (632.8 nm, 30 W/m2, 5-20 J/m2) on the transformation of Escherichia coli cells with plasmid DNA was studied. The irradiation of a mixture of bacterial cells and plasmid DNA increased the transformation efficiency 2.5-3 times, thus offering an alternative to the heat treatment commonly used. In contrast to the standard techniques, the laser-induced increase in the transformation efficiency was accompanied by a 1.7- to 2-fold increase in cell survival. The effect of the 632.8-nm light, know to be absorbed by membrane porphyrin components, is supposed to be mediated via a modification in the replication and transformation DNA-membrane complexes in E. coli cells.

[A bacterial model for research on the effect of laser radiation on the intensity of cell division]. / Bakterial'naia model' dlia issledovaniia vliianiia lazernogo izlucheniia na intensivnost' kletochnogo deleniia.

A bacterial model is proposed for the prognosing, at the cellular level, of the effectiveness and safety of low-intensity laser therapy. In experiments with E. coli WP2, a study was made of the effect of continuous optical radiation as well as of pulse radiation at medical installations "Uzor" (890 nm, 1.2 x 10(-1) W/m2, 3400 Hz) and "Omega" (950 nm, 1.2 x 10(3) W/m2, 2-5000 Hz). A technique has been developed to determine a minimum dose of low-intensity radiation that provides normalization of the cell division rate at a pathological site excluding the risk of the uncontrolled proliferation of the surrounding tissues.

[The effect of substrates and irradiation with low intensity visible light on the rate of division of Escherichia coli]. / Vliianie substratov i oblucheniia nizkointensivnym vidimym svetom na skorost' deleniia bakterii Escherichia coli.

The effect of He--Ne laser irradiation (lambda = 632.8 nm, D = 4.10(3) J/m2) on the growth of Escherichia coli cultures was studied in a minimal medium containing glucose, glycerol of arabinose. The irradiated cultures immediately started to divide with a virtually identical specific growth rate (kappa = 0.78, 0.8 and 0.8 h-1) whatever the growth rate and the latent period of the parent cultures were. The ratio between cell numbers in the irradiated and non-irradiated cultures was highest 1 h after the irradiation: 1.25, 1.3 and 1.5 for the glucose, glycerol and arabinose cultures, respectively. Apparently, the irradiation with visible light of a low intensity creates an additional proton gradient and thus stimulates a new replication and division cycle in the population of cells whose membranes do not have delta pH necessary for the initiation of these processes. The system under study can serve as a model for studying the delta pH-dependent stages in the regulation of cell division.

[Effect of He-Ne laser radiation on the bacteriophage T4-Escherichia coli system]. / Vliianie izlucheniia He-Ne lazera na sistemu bakteriofag T4-Escherichia coli.

Exposure of T4 bacteriophage, having no red light chromophores, to He-Ne laser (lambda = 632.8 nm) of 10(3)-6 X 10(4) J/m2 does not influence its lytic properties. Irradiation of E. coli WP2 bacteria with doses of 4-6 X 10(3) J/m2 causes a 1.25-1.35-fold increase in their ability to keep on the development of nonirradiated bacteriophage T4.

[Specificity of the lethal and mutagenic actions of pico-second laser pulses of 532-nm wavelength]. / Issledovanie spetsifiki letal'nogo i mutagennogo deistviia pikosekundnykh lazernykh impul'sov s dlinoi volny 532 nm.

A study was made of the lethal effect of pulse laser (second harmonic Nd+3:YAG laser of 532 nm, pulse length 3.3.10(-11) s, peak intensity from 4.10(12) to 1.10(14) W/m2) on HeLa cells at the phases of active and stationary growth, and lethal and mutagenic effects of this radiation on E. coli cells. As was shown, HeLa cells at both growth phases and E. coli cells exhibited low sensitivity to laser radiation at lambda = 532 nm.

[Lethal and mutagenic effect of the XeCl laser on Escherichia coli]. / Letal'noe i mutagennoe deistvie izlucheniia XeCl lazera na bakterii Escherichia coli.

The survival rate and reversions to tryptophan-independence of Escherichia coli after XeCl laser irradiation (lambda = 308 nm) within the dose range from 10(3) to 10(5) J/m2 have been studied to show that LD37 is 10(4) J/m2, the survival rate at a maximum dose of 10(5)J/m2 is 1 per cent, and the number of mutants per 10(6) cells survived is 100.

[Effect of low-intensity monochromatic visible light on the growth of Escherichia coli cultures]. / Vliianie nizkointensivnogo monokhromaticheskogo vidimogo sveta na rost kul'tury Escherichia coli.

The goal of this work was to study the effect of monochromatic visible light having a low intensity on Escherichia coli WP2 growth. The growth was accelerated by violet light (lambda = 404 nm) at a dose of 10--100 J/m2 and by blue (lambda = 454 nm), green (lambda = 520 to 560 nm), red (lambda = 633 nm) and far red light (lambda = 700 to 750 nm) at a dose of 10(3)--10(4) J/m2). The components of E. coli respiration chain may be primary photoreceptors in the cells.

[The effect of low-intensity light from the red and far red regions of the spectrum on Escherichia coli]. / Deistvie nizkointensivnogo sveta krasnoi i dal'nei krasnoi oblastei spektra na bakterii Escherichia coli.

The effect of red and far red light having a low intensity on Escherichia coli growth was studied. The growth accelerated when the culture was irradiated with the light at a dose of 1--4 X 10(3) J/m2. When the light of the two spectral regions was used together, the effect depended on the dose and order of the irradiation. It is possible that receptors for red light and for far red light interact in E. coli cells.

[Action of the radiation from a neon laser and from noncoherent blue light on Escherichia coli bacteria]. / Deistvie izlucheniia argonovogo lazera i nekogerentnogo sinego sveta na bakterii Escherichia coli.

It was shown that under defined conditions blue light can accelerate E. coli WP2 growth. The stimulatory effect is a function of radiation dose, intensity wave length, and postirradiation incubation time.