[Fibrinolytic activity of bacteria from Pseudomonas genus]. / O fibrinoliticheskoi aktivnosti bakterii roda Pseudomonas.

A strain of the genera Pseudomonas genera was found to possess hemolytic, fibrinolytic and thrombolytic activities. The fibrinolytic activity of the lyophilized unpurified preparation was 900 conventional units/mg. After incubation in the blood plasma, the activity completely remained. The preparation (1 microgram/ml, 750 micrograms of protein) obtained by precipitation with ammonium sulfate (80% saturation) completely lysed in vitro human blood thrombi for 50 min. The strain studied can find practical applications in medical industry.

[Survival of bacteria in the Artificial Mars unit]. / Vyzhivaemost' bakterii v ustanovke "Iskusstvennyi Mars".

The survival of bacteria was studied in the "Artificial Mars" apparatus reproducing a complex of physical extreme factors. Bacteria isolated from microbiocenoses subjected to the action of chemical extreme factors (hydrogen peroxide, catalytically active minerals) were shown to be most resistant among soil heterotrophic bacteria. Cells in the resting state caused by dehydration survived better than vegetative cells. It has been concluded that microorganisms quite different in their physiological requirements and ecological properties can exist in the habitats extreme for life conditions.

Biological studies of Martian soil analogues.

Results of the study of the influence of Martian soil analogues, both as described by American scientists and as prepared by us, and of hydrogen peroxide on the viability of microorganisms are presented. The experiments were carried out using mixtures of soil analogues with desert soil and black earth (chernozem) samples, and pure cultures of microorganism. Microorganisms capable of withstanding a concentration of hydrogen peroxide in the medium as high as 1.5-2.0% were isolated. None of the 40 strains of microorganisms studied, all belonging to different systematic and physiological groups, exhibited growth inhibition on solid media in the presence of Martian soil analogues. In view of the fact that Martian soil cannot contain microorganisms in great quantities, we suggest using electroadsorption for their concentration, to make detection reliable. A device was designed for this purpose, using the principle of electroadsorption on a polarisable carrier (sterile cotton wool or cheesecloth). The concentrated suspension of microorganisms thus obtained was then characterized by various physicochemical methods.

[Effect of hydrogen peroxide and hydrated ferric oxides on the metabolism of soil microflora]. / Vliianie perekisi vodoroda i gidratirovannykh okislov zheleza na metabolizm pochvennoi mikroflory.

The effect of hydrogen peroxide and the mineral limonite on the rate of microbial processes was studied in poor and rich soils. The dynamics of CO2 evolution can be registered upon addition of hydrogen peroxide to chernozem samples, which confirms the existence of metabolism of soil microorganisms. In experiments with desert soil, the evolution of O2 increases rather than that of CO2, which is probably due to an increase in the number of microorganisms producing catalase. Limonite stimulates the metabolic activity of microrganisms. The cultural and morphological properties of microflora are described, which are typical of soils incubated in the presence of limonite and hydrogen peroxide. This work supports the conclusion that, theoretically, the ground of Mars may contain microorganisms which have adapted, in the course of evolution, to high concentrations of hydrogen peroxide and hydrated iron oxides (of the limonite type) in the surrounding medium.

On methods of detection of extraterrestrial life.

New methods have been developed for detecting microbial growth from the microflora of desert soils. The first is a polarimetric method in which the fall in optical activity due to assimilation of D-glucose is followed. Detectable changes with desert soils were seen in a few hours, and the method can be employed with small amounts of material. The second method is the release of heat from metabolizable substrates as measured by a microcalorimeter. In the presence of glucose a characteristic response from desert soils was found within 24 hours.

[Determination of optical activity of the growth medium as a method for detection of extraterrestrial life]. / Opredelenie opticheskoi aktivnosti pitatel'noi sredy kak metod obnaruzheniia zhizni vne zemli

Determination of optical activity of the cultural medium can be used for detection of extraterrestrial life. The composition of the growth medium depends on the duration of the experiment. Automatic biological stations are sent to planets for a short time, and the best components of the growth medium are D-glucose and D-maltose; optical activity of the cultural broth disappears upon assimilation of these compounds. Tartaric acid is less suitable since the duration of the experiment increases several times and desert soils do not always contain microorganisms assimilating tartaric acid.