[Screening of α-L-Rhamnosidases and Peptidases among Actinobacterium and Bacilli].

Purpose: To carry out screening of peptidases and α-L-rhamnosidases producers among actinobacterium and bacilli. Methods: The biochemical methods of α-L-rhamnosidase, elastase, caseinolytic, fibrinolytic and collagenase activity determination have been used. Results: Among 31 strains of actinobacterium and 24 strains of bacilli it was not exhibited any enzyme with elactolytic activity, while a number of actinobacterium strains displayed high collagenase activity. As to bacilli, elastolytic activity was observed only in five strains, however its level is not an interest for future investigations. Bacillus subtilis 121 and 108 exerted enough high activity (0.100 and 0.092 U/mg of protein respectively). Conclusion: The most effective producer of collagenase and α-L-rhamnosidase is actinobacterium strain 6/5 isolated from nettle zhisosphere,while peptidase with fibrinolytic activity - B. subtilis 121 and 108. We believe these strains may be perspective for further researches.

[Research of Metachromatic Reaction of Saccharomyces cerevisiae].

This work is a continuation of research of the Chizhevsky-Velhover's bio-astronomic effect. Monitoring of volutin granule metachromatic staining of Saccharomyces yeasts (S. cerevisiae UCM Y-517, S. cerevisiae CRY, S. cerevisiae CNX, S. bayanus UCM Y-493, S. unisporus UCM Y-2065, S. rosinii UCM Y-2614, S. exiguus UCM Y-649) under conditions of different space weather was carried out. S. cerevisiae UCM Y-517, which displayed the metachromatic reaction in 96.7 % cases, showed the biggest sensitivity to the space weather changes. The changes in phosphoric metabolism of S. cerevisiae CNX cells, which can not synthesize exopolyphosphatases PPX1 and PPN1 (CF 3.6.1.11), did not influence the metachromatic reaction. Yeast cells grown on wort-agar displayed more intensive metachromatic reaction compared to those grown on YEPD-agar. However, increasing concentration of phosphorus in YEPD-agar improved visualization of the metachromatic staining. The strain S. cerevisiae UCM Y-517 is recommended as a model for monitoring of volutin granules metachromatic reaction in the research project "Heliomed" because of its high sensitivity to the space weather changes.

[GROWTH OF MICROMYCETES FROM DIFFERENT ECOLOGICAL NICHES ON AGAR NUTRIENT MEDIA].

Radial growth rate of (K(r)) 153 strains 6 species of micromycetes from different ecological niches was studied on 7 agar media: three standard (malt extract agar, potato-dextrose agar, Czapek's agar), and on agar media with plant polymers (carboxymethylcellulose, xylan, soluble starch and apple pectin). Endophytic and plant pathogenic strains (biotrophs) of all studied species did not differ significantly in their ability to grow on nutrient media of different composition--average values of K(r) for these two groups were the same (0,200 and 0,199 mm/h, respectively). Soil micromycetes (saprophytes) characterized by the lowest average growth rate (0,169 mm/h) and significantly differed from the endophytic and plant pathogenic ones. Average of the radial growth rates of studied microscopic fungi were higher on standard nutrient media than with plant polymers ones. Growth parameters of endophytes and plant pathogens of all studied species on various agar media differed from the soil strains. High growth rate of endophytic and plant pathogenic strains of Fusarium poae, Alternaria alternata and Ceratocystis sp. provides them the rapid colonization of plants. Penicillium funiculosum strains equally can exist as saprophytes in soil and as endophytic plant symbionts. A wide range of K(r) variation of endophytic dark pigmented Mycelia sterilia indicates the presence in this group of different species of micromycetes, which have no sporulation.

Study of adenovirus reproduction in different lymphoblastoid cell lines.

The comparative characteristic of the reproduction of adenovirus serotypes 2 and 5 (HAdV-C2 and -C5) in the various lymphoblastoid cell lines were studied. Rapid formation of infectious viruses in Raji, MP-1, Namalwa, BJAB, MT4 and Jurkat cells was marked and it was found to be close to the level of viruses during reproduction in permissive Hep-2 epithelial cells. Yield of infective adenovirus was low in B95-8 cells, which were chronically infected with Epstein-Barr virus (EBV). This may indicate the interference of Ad with EBV during super-infection. The CEM cells produced chronically low amounts of human adenovirus serotype 2.

Antibacterial activity of cerium colloids against opportunistic microorganisms in vitro.

The CeO2 sol with the size of nanoparticles 2-4 nm has been synthesized. It has been determined that the synthesized nanocrystalline cerium has antibacterial activity in vitro against different groups of opportunistic microorganisms: clinical strains of Escherichia coli, Staphylococcus aureus and Candida albicans. The rate of viability depression of test-cultures depends on the concentration of cerium dioxide nanoparticles and time of incubation. It is shown that the sol interacts with the bacterial cell surface. It is suggested that the observed differences of antibacterial action of nanocrystalline cerium dioxide can be related to the structural characteristics of the cell surface.

Microbial growth fluctuating in response to solar-terrestrial activity variations.

Populations of microorganisms display fluctuations in the variable physiological and biochemical properties during cultivation under constant laboratory conditions. A series of explanations were proposed for this phenomenon, and different factors were studied as possible regulators. It was found that such fluctuations possess cosmic rhythms, but no factor(s) were proposed that could sufficiently explain and predict the magnitude of changes that happened on a daily basis in the long-term experiments. In this study we investigated specific growth rate fluctuations of Saccharomyces cerevisiae yeasts that were marked daily during cultivation under constant conditions. The effects of different solar and terrestrial factors were then analysed. The significant correlation indices were found for growth rate fluctuations against solar wind speed and the number of flares M on the Sun. These two factors determined the cyclic nature of the growth rate fluctuations, and thus its general course of increase or decrease. The effects of several other factors (Flares C number, planetary A index variation, and changes in the atmospheric factors such as temperature and humidity) and their two-way interactions were significant in producing an equation to describe the magnitude of changes of the yeast's growth parameters. The R2 of the equation achieved 91% and adjusted R2 was 78%. It is obvious that temperature and humidity are the factors that cannot directly influence the yeast populations under laboratory conditions and thus we suppose that they only reflect modifications of the really important factor(s) that take place in the Earth's atmosphere. We have concluded that different solar and terrestrial factors are responsible for the fluctuations in the daily kinetic parameters of the yeast growth.