[Species specificity and reaction of bacteria to a 50 GHz magnetic field]. / Vidovaia spetsifichnost' reaktsii bakterii na magnitnoe pole chastotoi 50 Gts.

The growth of cultures of bacteria with different lipid content of cell membranes in response to a 40 min exposure to alternating magnetic field of 50 Hz, 18 mT was studied. Three important phenomena were revealed. A species specificity of responses of bacteria to the magnetic field, including both inhibition and activation, was observed. The changes in the kinetics of growth of bacterial culture correlate with the type of membrane lipid complex. The information on the exposure to magnetic field is memorized by the previously exposed distilled water, which makes itself evident in responses much more intensive than the responses of the same cultures exposed immediately in the culture medium.

[High resistance of some oligotrophic bacteria to ionizing radiation]. / Vysokaia ustoichivost' k ioniziruiushchei radiatsii nekotorykh oligotrofnykh bakterii.

The resistance against ionizing radiation of seven cultures of oligotrophic and eutrophic bacteria was investigated in the interval 0-360 Gr/h. It is determine that all of tested bacteria are distributed into three groups according to the lever of their resistance. Most resistant were: Methylobacterium organophilum, Pedodermatophilus halotolerans (LD50 = 270 Cr/h). These organisms are close to Deinococcus radiodurans in the survival. Middle resistance shown water-born ring-forming bacteria Flectobacillus major, Arcocella aquatica (LD50 = 173 and 210 Gr/h respectively). High sensitive were eutrophs: Pseudomonas fluorescens, Escherichia coli (LD50 = 43 and 38 Gr/h respectively). By use of X-ray microanalysis was shown that after the radiation potassium content in cell was increased and calcium content was decreased. The elements content in the cells of eutrophs (Escherichia coli) remains without change. In present paper are also discussed possible mechanisms of the resistance of oligotrophs against gamma-irradiation.

[Natural variability of Actinomyces lavendulae, a producer of cholesterol oxidase]. / Estestvennaia izmenchivost' Actinomyces lavendulae--produtsenta kholesterinoksidazy.

Five variants of Actinomyces lavendulae differing in the morphology of their colonies were found when natural variability of this organism was studied. A correlation was established between the colony morphology of the variants and their activity of cholesterol decomposition. The variants forming colonies of the basic and folded type had the highest activity. A variant with an elevated activity of cholesterol oxidase was selected. In order to maintain the high activity of the culture, it is necessary to examine its variability and to select variants corresponding to the basic type in their morphology.

[Hypocholesterinemic effect of cholesterol oxidase in the rabbit]. / Gipokholesterinemicheskoe deistvie kholesterinoksidazy v éksperimentakh na krolikakh.

Cholesterol oxidase (3 beta-hydroxysteroid oxidase) from the Actinomyces lavendulae mycelium oxidizes cholesterol of blood serum in vitro. The half-inactivation time for the enzyme in blood serum (37 degrees) is 90 min. After intravenous injection of the enzyme (1--2 units per kg) to rabbits with experimental hypercholesterinemia the cholesterol content in the blood is decreased directly proportional to the single dose of the enzyme and duration of injection. After 6-8 injections the level of non-esterified and total cholesterol is drastically decreased (by 90-97% and 65-68%, respectively). The acute toxicity of cholesterol oxidase preparations for mice decreases depending on the degree of the enzyme purification.

[Decomposition of human blood cholesterol by the enzyme from Actinomyces lavendulae]. / Razlozhenie kholesterina, soderzhashchegosia v krovi cheloveka, fermentnym preparatom iz Actinomyces Lavendulae.

In vitro experiments with enzymic decomposition of cholesterol contained in the human blood were carried out. The enzyme was obtained from the mycelium of Actinomyces lavendulae. As a result of incubation of blood samples in the presence of the enzyme at 37 degrees, the cholesterol content decreased and reached 30--43% of the initial value within 2 hours. The enzyme showed its specific effect only upon free cholesterol but not on its esters.

[Cholesterol breakdown by enzyme preparations extracted from Streptomyces lavendulae]. / Razlezhenie kholesterina fermentnymi preparatami, poluchennymi iz Streptomyces lavendulae

Cholesterol was decomposed by 75-90% during two hours by enzyme preparations from the disintegrated mycelium of Streptomyces lavendulae. The effect of concentrations of cholesterol and protein on the decomposition of cholesterol by the enzyme was studied; the higher the content of protein in a sample, the more rapidly cholesterol is decomposed; the rate of cholesterol decomposition increases with a decrease of its concentration. The optimum pH is 7.5-9.0. After dialysis and lyophilization, the activity of the enzyme preparations remains the same during two weeks, and then decreases by a factor of 1.5-2 in the course of the following thirty days.

[Activity of microorganisms decomposing cholesterol]. / Ob aktivnosti mikroorganizmov, razlagaiushchikh kholesterin

The rates of cholesterol decomposition was compared among cell suspensions of different microorganisms. Fifty seven cultures were studied: 2 strains of actinomycetes, 23 strains of proactinomycetes, 22 strains of mycobacteria, and 10 strains of bacteria. During four hours of incubation, 11 strains virtually did not decompose cholesterol at all, 10 strains decomposed it by up to 20 per cent, 21 strains by 20 to 70 per cent, and 15 strains by 70 to 100 per cent. The highest activity was displayed by Mycobacterium rubrum 297 and Mycobacterium sp. 2B, which decomposed all cholesterol in the sample within 4 hours. The high activity was also displayed by Proactinomyces sp. 2006, Nocardia opaca JMET 7030, and Nacardia erythropolis JMET 7252.

[Decomposition of cholesterol by Achromobacter candicans]. / Razlozhenie kholesterina Achromobacter candicans

The decomposition of cholesterol by the cell suspensions of Achromobacter candicans 42 and by the cell-free extracts of this bacterium was studied. The decomposition of cholesterol in the presence of the wet biomass during four hours of the incubation was 72.5 percent, and with the cells that were preliminarily lyophilized or treated by acetone 49.8 and 23.0 percent, respectively. The activity decreased from 70.0 to 50.0 percent if the biomass was kept at minus 3 degrees C during 70 days. The decomposition of cholesterol by the cell-free preparations (supernatant and protein after precipitation with ammonium sulphate to 0.7 saturation) constituted 40.0 percent of the cholesterol contained in a sample. One of the intermediate products of cholesterol decomposition was delta4-cholesten-3-one.