[Effect of light-isotope water on growth of bacterial culture].

The stimulating effect of light-isotope water on microbial growth was demonstrated in bacterial culture Pseudomonas esterophilus. Nutrient medium was prepared of mineral salts and ethyl acetate as a source of carbon dissolved in light-isotope water with ppm 35 and 70; the control medium contained same components dissolved in distilled water. The investigation showed an increase in the number of bacterial cells in the exponential stage of growth in static culture in light-isotope water as compared with the control. Specifically, accretion made up 87.3 and 35.2% in light-isotope water with ppm 35 and 70, respectively. In an hour, the number of cell divisions increased by 6.7% and 3.3%, respectively. Therefore, light-isotope water stimulates the metabolic activity and, consequently, growth of bacterial cells.

[Iodine-containing urine preservative].

One of the formidable problems of exploration missions is creation of autonomous water-closed life support systems. Sources of water for regeneration could be various water-containing human wastes including urine, the most chemically contaminated liquid. Prior to physical/chemical regeneration, urine first must be decontaminated in order to put a stop to microbiological processes that form harmful and volatile compounds contaminating condensate and drastically reducing the service life of afterpurifucation filters. Bactericide, sporocide and fungicide effectiveness of two iodine-containing preservatives was tested. One of them contains a water solution of iodine--potassium iodide and sulphuric acid. The other has medical poly-vinyl pyrrolidone to neutralize iodine toxicity. The broad antimicrobial spectrum of two iodine-containing urine preservatives and adaptability of microorganisms to a new environment are key arguments for serial use of these and other preservatives in regenerative physical/chemical systems of water supply in space exploration missions.

[Removal of harmful admixtures from a surrogate atmospheric condensate of a closed habitat with the help of a cultivated bacterial association].

Tested was an idea to eliminate six harmful admixtures reside in a surrogate of atmospheric condensate of closed habitats by a cultivated bacterial association. The purpose was to select members of the bacterial associations that would assimilate acetone, acetic acid, ethanol, ethyl acetate, methylamine and ammonia as free, so immobilized on insoluble cellular polyvinylformal. The resulted association of three bacterial species showed the ability to transform into end products a six-component surrogate of atmospheric condensate. Methylopila capsulata VKM V-1606 metabolized methylamine, Paracoccus denitrificans VKM V-1324--acetone. Pseudomonas esterophilus VKM V-1736 D was found to act as an ethyl acetate destructor decomposing the admixture to ethanol and acidic acid which were oxidized also by this species to carbon dioxide and water. Each of these bacterial strains in the test association metabolized ammonia as a source of nitric nutrition.

[Biotransformation of organic substances by an immobilized associative bacterial culture]. / Biotransformatsiia organicheskikh veshchestv immobilizovannoi assotsiativnoi bakterial'noi kul'turoi.

Bacterial strains were screened to transform to end-products (carbon monoxide and water) elevated concentrations of acetone, acidic acid, and ethanol in a biocatalyst with an immobilized bacterial association cultivated on solid foam polyvinyl acetate (FPVA). The innocuous association amalgamated Paracoccus denitrificans VKM V-1324, Pseudomonas esterophilus VKM V-1736D and Achromobacter parvulus VKM V-1541D. The biocatalyst was tested with the help of classic methods and equipment for microbes cultivation. Microbial growth was assessed in the optical density units. Comparative evaluation of the biocatalytic activity was performed on gas-chromatographer Pue Unicam-104. Based on test results, specific rates of oxidation of acidic acid, ethanol and acetone per one g of FPVA were 0.75, 0.72, and 0.67 mg/hr, respectively.

[Principles of developing methods for decontamination and preservation of water-containing human wastes in a mission to Mars]. / Printsipy podkhoda k razrabotke sredstv obezzarazhivaniia i konservatsii vodosoderzhashchikh otkhodov zhiznedeiatel'nosti cheloveka primenitel'no k marsianskoi ékspeditsii.

Chemical and microbial safety will be one of the major functions of a closed eco-system aboard piloted interplanetary vehicle. Methods for decontamination and preservation of water-containing human wastes (WHW) should be developed on the assumption that WHW are a labile biochemical system biological and chemical processes of which are intricately dependent on preservatives, regenerative water quality, structural material off-gassing, and methods of WHW collection, storage, and management.

[Immobilized catalase in water purification systems]. / Immobilizovannaia katalaza v sistemakh ochistki vody.

The results of studies on producing the biocatalyst based on catalase immobilized in the fibers from triacetate are presented. The catalase producer is Penicillium fungus. Catalase was produced by precipitation with the use of ethyl alcohol from the cultural fluid with separate and unseparate mycelium. The highest activity of catalase in the cultural fluid is seen on the nutrient medium containing 4% of carbon source. For immobilization the water solution of enzyme was concentrated in the vacuum-rotor evaporator at temperature of 25 degrees C. The enzyme was included in the structure of fibers during the process of their formation. Of the fiber-producing polymers (cellulose triacetate, chlorine, polysulphone) the most enzymatic activity has the catalase-containing fibers derived from the cellulose triacetate, in this case, the fine fibers of biocatalyst have the higher specific activity. It is established that the fibers obtained by using catalase of microbiological origin possess high stability and their activity does not practically change in the aqueous environment. The unpurified catalase is one and a half higher than at purified catalase. Under laboratory conditions there turned out the experimental batches of fibers and there conducted their endurance tests. Catalase included in cellulase triacetate has effectively functioned during a period of 2 years purifying the distilled water containing 50 mg/l of hydrogen peroxide.