[Artificial immobilization of the two-membered bacterial system Bdellovibrio bacteriovorus 109D--Escherichia coli B in polyacrylamide gel]. / Iskusstvennaia immobilizatsiia dvukhkomponentnoi bakterial'noi sistemy Bdellovibrio bacteriovorus 109D--Escherichia coli v poliakrilamidnom gele.

The interaction of a parasite with a host was studied in the two-membered bacterial system, Bdellovibrio bacteriovorus 109D and Escherichia coli B, immobilised in polyacrylamide gel (PAAG). The parasite localised inside the host cells was found to be more resistant to the toxic action of PAAG components than free B. bacteriovorus. The latter lost its mobility and was inactivated in the matrix of the carrier whereas the intracellular parasite had a normal cycle of development in the periplasm of the infected cells. The dynamics of B. bacteriovorus and E. coli incidence in the liquid phase and in PAAG granules was studied while the immobilised system was incubated. The interaction in the immobilised system could be intensified by growing more bacterial host cells in PAAG particles. The immobilisation was shown to favour the survival of the parasite and the host in the two-membered system.

[Role of carbohydrate-protein recognition in the process of Bdellovibrio attaching to bacterial host cells]. / Rol' uglevod-belkovogo uznavaniia v protsesse prikrepleniia Bdellovibrio k kletkam bakterii-khoziaev.

The authors discuss the role of carbohydrates in the surface layer of the cell wall in the process of Bdellovibrio attachment to host-bacteria cells. The paper presents the results of inhibitory analysis using sugars conducted with two model systems as well as the data about the effectiveness of the interaction between parasite cells and host cells after the modification of their surface polysaccharide layer with concanavalin A and sodium periodate.

[Separation of exoparasitic bacteria of the genus Micavibrio from the cells and membranes of the host bacterium]. / Otdelenie ékzoparaziticheskikh bakterii roda Micavibrio ot kletok i membran bakterii-khoziaina.

Conditions for separation of Micavibrio aeruginosavorus ARL-1 from cells and membranes of host-bacteria Pseudomonas aeruginosa have been developed. Differential centrifugation and ficoll density-gradient centrifugation were applied to purify a mixed culture. A fraction localized in the zone of 12-15% ficoll is a sufficiently homogenous suspension of the exoparasite . It meets requirements of purity of the biomass destined for biochemical investigations.

[New species of exoparasitic bacteria of the genus Micavibrio infecting gram-positive bacteria]. / Novyi vid ékzoparaziticheskikh bakterii roda Micavibrio, porazhaiushchikh gramotritsatel'nye bakterii.

A new species of exoparasitic bacteria, Micavibrio aeruginosavorus sp. nov., was isolated on the host bacterium, Pseudomonas aeruginosa. Its diagnosis is given.

Peculiarities of the fatty acid composition of Bdellovibrio.

The fatty acid composition of twelve Bdellovibrio strains isolated upon the growth on bacteria of various taxonomic groups was studied. A dependence of the lipid composition of bdellovibrios on that of bacteria they were parasitizing on was shown. Data pointing to the selective incorporation of fatty acids of host bacteria by bdellovibrios were obtained. Bdellovibrio membranes were shown to contain monounsatured fatty acids with different positions of double bonds indicating that there are at least two alternative mechanisms of synthesis of these acids in the parasites.

[Method of determining the pteridine sensitivity of parasitic bacteria of the genus Bdellovibrio]. / Sposob opredeleniia chuvstvitel'nosti k pteridinu paraziticheskikh bakterii roda Bdellovibrio.

The method of determination of parasitic bacteria Bdellovibrio sensitivity to pteridine has been described. The method suggested can be used in research work for diagnostics of Bdellovibrio genus bacteria.

[Micavibrio admirandus gen. et sp. nov]. / Micavibrio admirandus gen. et sp. nov.

Micavibrio gen. nov. (M.L. fem. n. mica--a tiny thing and M.L. masc. n. Vibroia generic name, M.L. masc. n. Micavibrio a tiny vibrio). Cells are single, small curved rods, in motile stage with a single polar not sheathed flagellum. Reproduced by binary division, gram-negative. Cells attach to host-bacteria cells and grow as exoparasites destroying the host, may exhibit a host-range specificity. The G + C content of the DNA of the strain examined is 57,1% M. Isolated from sewage waters. The type species is M. admirandus sp. nov. M. admirandus sp. nov (M.L. adj. admirable). Curved gram-negative rods 0,25-0,35X0,6-1,0 micron with a single flagellum 13-15 nm in width. Motile cells attach to the cell wall of the bacterium. Pseudomonas maltophilia, lose the motility and grow as exoparasites destroying the host. Develops only on. P. maltophilia cells and is unable to multiply in the absence of a host organism. Resistant to a vibriostatic agent pteridine 0/129. The G + C content of the DNA of the strain examined is 57,1% M. The type strain ARL-14 is maintained in the culture collection of the Institute of Biochemistry and Physiology of Microorganisms, USSR Academy of Sciences. The type strain has been isolated from sewage waters of the town of Pushchino.

[Comparative study of the membrane protein composition of bacteria in the genus Bdellovibrio]. / Sravnitel'noe izuchenie belkovogo sostava membran bakterii roda Bdellovibrio.

The protein composition of membranes was studied in 17 Bdellovibrio strains by electrophoresis in polyacrylamide gel in the presence of sodium dodecyl sulfate. No similarity in the protein composition of membranes was found in the strains grown on cells of one and the same host. A dendrogram constructed basing on the similarity coefficients between the strains allowed to subdivide them into 3 groups according to the protein composition of their membranes. This correlated with the other phenotypic features and genotaxonomic data.

[Comparative characteristics of the Bdellovibrio strains isolated from river water and sewage]. / Sravnitel'naia kharakteristika shtammov Bdellovibrio, vydelennykh iz rechnoi i stochnykh vod.

The morphology, the host ranges, the resistance to pteridine and the nucleotide composition of DNA were compared in 12 newly isolated and 10 collection strains of Bdellovibrio. The significance of properties used for the taxonomy of these organisms was evaluated. The host ranges of Bdellovibrio strains are heterogeneous with respect to the taxonomy of host bacteria. The specificity of the parasite depends to a significant degree on the host bacterium in which it grows. All the strains including Bd. starrii which was described earlier as a pteridine resistant species are sensitive to pteridine. Therefore, such properties as the host range action and the response to pteridine cannot be used for diagnostics of Bdellovibrio species. The strains were found to be very heterogeneous with regard to the nucleotide composition of the DNA. Eight out of the 12 newly isolated strains were assigned to the species Bd, bacteriovorus.

Protein composition of Bdellovibrio bacteriovorus and Escherichia coli membranes during their interaction.

A comparative study of membrane proteins of Bdellovibrio bacteriovorus and host-bacteria Escherichia coli was performed by polyacrylamide gel electrophoresis in presence of sodium dodecyl sulphate. Infection of E. coli cells by bdellovibrions resulted in the loss of some high-molecular proteins and appearance of new ones in the host-bacteria membranes. The possible role of parasite proteases in degradation of host-bacteria membrane proteins is discussed.

Detection of polyphosphates and enzymes of polyphosphate metabolism in Bdellovibrio bacteriovorus.

Bdellovibrio bacteriovorus cells, parasitizing in E. coli, contain a considerable amount of inorganic polyphosphates, 55% of the total pool of which is due to the most polymeric acid-insoluble polyphosphates. B. bacteriovorus contains enzymes participating both in the synthesis and consumption of polyphosphates, i.e. 1,3-diphosphoglycerate: polyphosphate phosphotransferase, polyphosphate glucokinase, polyphosphatase, tripolyphosphatase, pyrophosphatase, acid and alkaline phosphatases. The possible role of high-molecular polyphosphates in the vital activity of the bacterial parasite B. bacteriovorus is discussed.

[Dynamics of the interaction of Bdellovibrio bacteriovorus with the bacterial host under aerobic and anaerobic conditions]. / O dinamike vzaimodeistviia Bdellovibrio bacteriovorus s bakteriei-khoziainom v aérobnykh i anaérobnykh usloviiakh.

Bdellovibrio bacteriovorus can interact with the host bacterium cells under aerobic and anaerobic conditions. The dynamics of the interaction between the parasite and the host depended on the regime of incubation. The latent period and the time at which Bd. bacteriovorus reached the stationary level became shorter under aerobic conditions. Lysis of the host bacterium cells under aerobic conditions proceeded more effectively, at a higher rate, and after a shorter period of the constant titre than under anaerobic conditions.

[Fluctuations in the numbers of Bdellovibrio bacteriovorus and host bacteria in a 2-component system]. / Kolebaniia chislennosti Bdellovibrio bacteriovorus i bakteriikhoziaina v dvukhkomponentnoi sisteme.

The number of interacting organisms in a two-membered bacterial "Bdellovibrio bacteriovorus--bacterium-host" system varied within a long period of time. The variations occurred in the counterphase and had a complicated irregular character with an altering period. The Volterra principle of collisions can be applied to this type of interaction between microorganisms.

[Effect of temperature on the dynamics of interaction of Bdellovibrio bacteriovorus with host bacteria]. / Vliianie temperaturnogo faktora na dinamiku vzaimodeistviia Bdellovibrio bacteriovorus s bakteriei-khoziainom.

The dynamics of the interaction between Bdellovibrio bacteriovorus and the host bacterium was found to depend on temperature. The maximum rate of infection was found at 37 degrees C. The maximum yield of Bdellovibrio and the maximum lysis of the host cells occurred at 22.5 degrees C. The cardinal points, at which no interaction was observed, have been determined. It is concluded that B. bacteriovorus belongs to mesophilis microorganisms.