The role of microbial low-molecular-weight autoregulatory factors (alkylhydroxybenzenes) in resistance of microorganisms to radiation and heat shock

Эль-Регистан, Г. И.; Mulyukin, A. L.; Nikolaev, Yu. A.; Stepanenko, I. Yu.; Kozlova, A. N.; Martirosova, E. I.; Shanenko, E. F.; Strakhovskaya, M. G.; Ревина, А. А.

doi:10.1016/j.asr.2005.02.070

Cited by 28 publications

(12 citation statements)

References 22 publications

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“…Also soils contain various organics, including pigments and microbial's growth autoregulators. It is shown that these substances play an important role in the stress tolerance of microorganisms [18,[78][79][80][81]. There is also information on the higher radioresistance of microorganisms in soils with high concentrations of humus, but these data are contradictory [82].…”

Section: Irradiation Of Pure Bacterial Cultures With Accelerated Elecmentioning

confidence: 99%

Survivability of Soil and Permafrost Microbial Communities after Irradiation with Accelerated Electrons under Simulated Martian and Open Space Conditions

et al. 2018

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Abstract:One of the prior current astrobiological tasks is revealing the limits of microbial resistance to extraterrestrial conditions. Much attention is paid to ionizing radiation, since it can prevent the preservation and spread of life outside the Earth. The aim of this research was to study the impact of accelerated electrons (~1 MeV) as component of space radiation on microbial communities in their natural habitat-the arid soil and ancient permafrost, and also on the pure bacterial cultures that were isolated from these ecotopes. The irradiation was carried out at low pressure (~0.01 Torr) and low temperature (−130 • C) to simulate the conditions of Mars or outer space. High doses of 10 kGy and 100 kGy were used to assess the effect of dose accumulation in inactive and hypometabolic cells, depending on environmental conditions under long-term irradiation estimated on a geological time scale. It was shown that irradiation with accelerated electrons in the applied doses did not sterilize native samples from Earth extreme habitats. The data obtained suggests that viable Earth-like microorganisms can be preserved in the anabiotic state for at least 1.3 and 20 million years in the regolith of modern Mars in the shallow subsurface layer and at a 5 m depth, respectively. In addition, the results of the study indicate the possibility of maintaining terrestrial like life in the ice of Europa at a 10 cm depth for at least~170 years or for at least 400 thousand years in open space within meteorites. It is established that bacteria in natural habitat has a much higher resistance to in situ irradiation with accelerated electrons when compared to their stability in pure isolated cultures. Thanks to the protective properties of the heterophase environment and the interaction between microbial populations even radiosensitive microorganisms as members of the native microbial communities are able to withstand very high doses of ionizing radiation.

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Section: Irradiation Of Pure Bacterial Cultures With Accelerated Elecmentioning

confidence: 99%

Survivability of Soil and Permafrost Microbial Communities after Irradiation with Accelerated Electrons under Simulated Martian and Open Space Conditions

et al. 2018

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“…Formation of AHBs com plexes with enzyme proteins caused changes in their conformation and, accordingly, in their functional activity and stability [7,10,11]. In addition, our ear lier works demonstrated a direct interaction between AHBs and the DNA accompanied by alterations in its topology and physicochemical properties [8].…”

mentioning

confidence: 93%

“…Previous studies on this subject revealed that the molecular mechanisms of the regulatory effects of AHBs were based on their capacity for nonspecific binding to cell biopolymers such as proteins and the DNA, as well as to membrane lipids, due to the forma tion of hydrogen bonds and hydrophobic and electro static interactions [7][8][9][10]. Formation of AHBs com plexes with enzyme proteins caused changes in their conformation and, accordingly, in their functional activity and stability [7,10,11].…”

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Involvement of alkylhydroxybenzenes in the Escherichia coli response to the lethal effect of UV irradiation

et al. 2012

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This work is concerned with the role of alkylhydroxybenzenes (AHBs), chemical analogs of the autoregulatory microbial d 1 factors, on the development of the stress response of bacterial cells to UV irradi ation, including SOS system induction, preservation of cell viability, and S R phase transitions of the Escherichia coli test strain with the bioluminescence genes cloned under the control of the recA gene pro moter. UV irradiation, a natural stress factor, and an increase in AHB concentrations were found to elicit uni form responses in bacteria, indicating that AHBs function as alarmones, i.e., alarm signals. It was revealed that preincubating bacteria with alkylhydroxybenzenes considerably enhanced their viability upon irradiation with lethal UV doses; this was accompanied by a relative decrease in the SOS response activity and a concom itant increase in the frequency of phase transitions. The efficiency of the protective action of AHBs increased with an increase in their hydrophobicity degree. The probable mechanism of the protective effect of AHBs is discussed, based on their capacity for the interaction with biopolymers, which results in changing their struc tural organization and conferring resistance to a broad spectrum of stress factors. Such a "passive" protective mechanism reduces the susceptibility of DNA to UV irradiation, causing a decrease in the parameters related to the SOS system induction that is responsible for the "active" protective mechanism in bacterial cells. As a result, viability retention under the lethal influence of UV irradiation is possible at minimal values of repair activity and is accompanied by an increase in the phenotypic variability of the surviving part of a bacterial population.

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“…In recent years, experimental works appeared in which the action of new biologically active substances, chemical analogues of microbial anabiosis autoinductors such as hexyl and methylre sorcinols [7][8][9][10][11][12][13], on the structural, dynamic, and functional properties of proteins was studied. Alkylre sorcinols are known and are of interest because, at cer tain concentrations, fairly rapidly cause the transition of microbial cells from the vegetative into dormant (anabiotic) state [14,15]. It was suggested in several works that biologically active substances with such a strong action can be chemical shaperons [7,10,13,16].…”

Section: Introductionmentioning

confidence: 98%

Possible mechanisms of the influence of hexylresorcinol on the structure-dynamic and functional properties of lysozyme protein

Krupyanskiǐ

Abdulnasyrov

Лойко

et al. 2012

Russ. J. Phys. Chem. B

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The influence of hexylresorcinol on the structure, equilibrium fluctuations, and functional activ ity of water soluble enzyme lysozyme was studied over a wide range of hexylresorcinol concentrations. Hex ylresorcinol was found to be not only a stabilizer of lysozyme. At low hexylresorcinol concentrations (2 to 10 molecules per lysozyme globule), the activity of lysozyme sharply increased; activity began to decrease as the concentration grew. The influence of hexylresorcinol on the structural, dynamic, and functional lysozyme characteristics is well described by models of preferential hydration and preferential protein interaction with hexylresorcinol. The hexylresorcinol molecule consists of hydrophobic (alkyl radical) and hydrophilic (aro matic nucleus) moieties, which has additional regulatory action on the functional activity of lysozyme. As the concentration of hexylresorcinol increases, the effect of regions with preferential hydration begins to notice ably predominate over the effect of preferential interaction with hexylresorcinol. At hexylresorcinol concen trations higher than 100 molecules per lysozyme globule, the activity of lysozyme is fully inhibited. This is caused by the preferential hydration of the protein with the displacement of hexylresorcinol from direct con tacts with it. The displacement of hexylresorcinol causes the formation of high density hexylresorcinol micelles. Dense micelles interfere with the approach of substrates to the protein and fully inhibit its functional activity. The complete inhibition of lysozyme activity occurs at hexylresorcinol concentrations lower by an order of magnitude than glycerol inhibiting concentrations.

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The role of microbial low-molecular-weight autoregulatory factors (alkylhydroxybenzenes) in resistance of microorganisms to radiation and heat shock

Cited by 28 publications

References 22 publications

Survivability of Soil and Permafrost Microbial Communities after Irradiation with Accelerated Electrons under Simulated Martian and Open Space Conditions

Survivability of Soil and Permafrost Microbial Communities after Irradiation with Accelerated Electrons under Simulated Martian and Open Space Conditions

Involvement of alkylhydroxybenzenes in the Escherichia coli response to the lethal effect of UV irradiation

Possible mechanisms of the influence of hexylresorcinol on the structure-dynamic and functional properties of lysozyme protein

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