[Susceptibility of archaea to the antibiotic effect of the parasporal inclusion proteins from Bacillus thuringiensis subspecies]. / Chuvstvitel'nost' arkhei k antibioticheskomu deistviiu belkov parasporal'nykh vkliuchenii razlichnykh podvidov Bacillus thuringiensis.

The proteins of parasporal inclusions from three Bacillus thuringiensis subspecies (kurstaki, amagiensis, and monterrey) inhibited growth of methanogenic archaea of two species belonging to two genera, Methanobrevibacter arboriphilus and Methanosarcina barkeri. The minimal inhibitory concentrations of these proteins were 20 to 50 micrograms/ml. Lysozyme exhibited similar bactericidal effect on archaea. The perspective of comparative studies on the effect of polyfunctional proteins on bacteria and archaea is discussed.

[A comparison of the antibacterial activity of the parasporal bodies of different bacilli]. / Sravnenie antibakterial'noi aktivnosti parasporal'nykh vkliuchenii razlichnykh batsill.

Solutions of the parasporal bodies of Bacillus sphaericus, B. laterosporus, and several B. thuringiensis subspecies display antibacterial activity showing the potential of membranotropic action of the body proteins. Comparison of the antibiotic effect of various delta-endotoxins of B. thuringiensis made it possible to identify highly active unique proteins. This approach forms the basis of goal-directed search for organisms sensitive to polypeptides of various bodies. It has already been established that delta-endotoxins of B. thuringiensis ssp. amagiensis cause the death of representatives of the fourth (in addition to the three previously known) order of insects, Isoptera.

[Sensitivity of dissociation variants of Micrococcus luteus to the action of delta-endotoxins of Bacillus thuringiensis]. / Chuvstvitel'nost' dissotsiantov Micrococcus luteus k deistviiu delta-éndotoksinov Bacillus thuringiensis.

Endotoxins of Bacillus thuringiensis subsp. tenebrionis produced an antibiotic effect on three out of the four species of micrococci tested, showing an activity of 10-23 units/mg, comparable with that of bacitracin. The R variants of Micrococcus luteus were more than twice as resistant to the action of delta-endotoxins as cells of the S and M types. Enhanced growth of the tested microorganisms at concentrations of antibiotics large enough to inhibit the growth of the S and M variants, but insufficient to suppress the R-variant, was shown to be determined by the intense development of the latter variant.

[Scanning tunneling and electron microscopy of parasporal crystals in Bacillus thuringiensis]. / Skaniruiushchaia tunnel'naia i élektronnaia mikroskopiia parasporal'nykh kristallov Bacillus thuringiensis.

Comparison of the forms of parasporal inclusions in Bacillus thuringiensis subsp. kurstaki and B. thuringiensis subsp. tenebrionis under a scanning electron microscope showed that, in addition to bipyramidal and cuboid crystals, cells of the subspecies kurstaki are able to form crystals taking the shape of flat parallelopipeds typical of the subspecies tenebrionis. The inclusions in the subspecies tenebrionis vary in size and electron density. Examination of the structure of crystals in B. thuringiensis subsp. tenebrionis under a scanning tunneling microscope showed that delta-endotoxins in the crystals are assembled in globules 5.0 nm in diameter and 1.0 nm in height. The globules are connected by its bases and form chains. The subunits of tetragonal crystals in the subspecies tenebrionis are vertically oriented with respect to the chain axis, as was revealed by other methods for subunits of bipyramidal crystals of the subspecies kurstaki.

[Comparative characteristics of mutants of Bacillus thuringiensis subsp. Kurstaki]. / Sravnitel'naia kharakteristika mutantov Bacillus thuringiensis subsp. Kurstaki.

A study of physiological and biochemical properties of 12 strains of Bacillus thuringiensis subsp. kurstaki was performed. The strains studied included natural isolates similar to the type strain in their properties, a Cry-Spo+ mutant, and also mutants assigned to C-1 or C-73 crystovar according to the properties of their parasporal crystals and the ability to hydrolyze esculin, generate acid from salicin, and exert urease activity. The crystals produced by C-1 crystovar cultures were three times larger than those formed by C-73 crystovar bacteria; their distinctive feature was pathogenicity for mosquito larvae, and their effect on other insects (gypsy moth and meadow moth) was on the average twofold greater than the effect of C-73 crystovar crystals. A study of the antibacterial action of delta-endotoxins of B. thuringiensis subsp. kurstaki allowed us to more clearly elucidate the reasons for the differences in biological activity of C-1 and C-73 crystovars. Comparative analysis of the data obtained confirmed that the effect of delta-endotoxins, formed per unit volume of the culture liquid, on insects and microorganisms is an important characteristic of B. thuringiensis strains. Of all the strains studied, the Cry-Spo+ mutant was the most potent producer of proteases and lecithinase.

[Influence of carbon sources on the biological activity and morphology of Bacillus thuringiensis parasporal crystals]. / Vliianie istochnikov ugleroda na biologicheskuiu aktivnost' i morfologiiu parasporal'nykh kristallov Bacillus thuringiensis.

The influence of the carbon source on biological activity and morphological properties of the parasporal crystals of Bacillus thuringiensis subsp. kurstaki cultivated on three different media has been studied. Biological activity of delta-endotoxins contained in crystals was tested according to their impact on insects and microorganisms. Variations in carbon sources composition resulted in changes of biological activity and morphology of crystals, caused by alterations in synthesis rate of various delta-endotoxins contained in the crystals. Variations in the content of a certain carbon source (e.g. starch) in the medium produced no effect on the crystals properties, and the content variations of the delta-endotoxins content was proportional to the producer biomass. Control of the antibacterial effect of delta-endotoxins allows a valid evaluation of their biological activity under various growth conditions as well as comparison of the biological potential of entomopathogenic chemicals for plant protection containing delta-endotoxins with different specificity of insecticidal activity.

[Correlation between insecticidal and antibiotic activities of Bacillus thuringiensis parasporal crystals]. / O korreliatsii mezhdu insektitsidnoi i antibioticheskoi aktivnostiami parasporal'nykh kristallov Bacillus thuringiensis.

The work was concerned with studying the insecticide and antibiotic activities of solutions containing parasporal crystals of several Bacillus thuringiensis subspecies. The correlation coefficients of these values were determined. A direct correlation was established between the insecticide and antibiotic activities of solutions of parasporal crystals from several B. thuringiensis subspecies. Therefore, the quality of bacterial insecticides can be controlled by assaying the antibiotic activity of polypeptide crystals in biotechnology.

[The role of bitoxibacillin components in the manifestation of its biological activity]. / Opredelenie roli komponentov bitoksibatsillina v proiavlenii ego biologicheskoi aktivnosti.

New methods were developed and applied to quantitative determination of beta-exotoxin and antibiotic activity of delta-endotoxin with respect to Micrococcus spp. in bitoxibacillin (BTB) and the fermentation broths prepared under industrial conditions. The biosynthesis of beta-exotoxin in the period of its maximum accumulation during the fermentation was estimated. It was shown that the primary biological effect of BTB on insects consisted in the actions of beta-exotoxin and delta-endotoxin. Biological activity of each of the entomocidal components of the entomocidal components of BTB did not practically correlated with the number of viable spores. There was a correlation between the antibiotic activity of crystalline B. thuringiensis subsp. thuringiensis solutions and the insecticidal activity of the entomopathogenic preparations. Determination of beta-exotoxin and antibiotic activity of delta-endotoxin might be used as a complex procedure for testing the quality of BTB. The method for estimating antibiotic activity of the crystal solutions allowed one to assay the biological activity of other preparations based on Bacillus thuringiensis non-synthesizing beta-exotoxin.

[Effect of amino acids on exoprotease synthesis by Bacillus thuringiensis]. / Vliianie aminokislot na sintez ékzoproteazy Bacillus thuringiensis.

The influence of certain L-amino acids and their mixtures on the synthesis of exoprotease from Bacillus thuringiensis was studied. Physiological experiments showed that the mixture of 20 amino acids added to the artificial medium repressed the synthesis of exoprotease. Among the compounds studied there are both the compounds which stimulate the synthesis of exoprotease (glutamic and aspartic acids, glycine), and the compounds which repress the synthesis of the enzyme (proline, tryptophane, tyrosine, asparagine, serine, cystein). None of the amino acids caused a change in the exoprotease activity. It has been assumed that the repression of the protease synthesis in the presence of the amino acids is accomplished by ammonium ions, which are formed when using the amino acids of Bac. thuringiensis. The glutamine synthetase activity of cells was determined during the growth of Bac. thuringiensis both on a medium containing triptone and after the addition of certain amino acids to the cell suspension. The correlation between the influence of different amino acids on the synthesis of exoprotease and the glutamine synthetase activity was demonstrated.

[Effect of proteins on exoprotease synthesis by Bacillus thuringiensis]. / O vliianii belkov na sintez ékzoproteazy Bacillus thuringiensis.

Bacillus thuringiensis was shown to grow better in media with albumin, gelatin and casein than in a chemically defined medium; proteins did not induce the synthesis of exoprotease. Two maxima were found in the enzyme synthesis: the first one at the exponential phase of the cultural growth, and the second one during spore formation by the culture. The synthesis at the exponential growth phase was susceptible to nitrogen metabolite repression while the synthesis of exoprotease at the stationary phase of growth was not repressed in the presence of high concentrations of ammonium ions in the medium.

[Effect of different carbon and purine nucleotide sources on exoprotease synthesis by Bacillus thuringiensis]. / Vliianie razlichnykh istochnikov ugleroda i purinovykh nukleotidov na sintez ékzoptoteazy Bacillus thuringiensis.

Bacillus thuringiensis cells, depending on their physiological state, produce different quantities of exoprotease. Easily metabolizable carbon sources in the medium can affect the process in the opposite way: they inhibit synthesis of the enzyme by the cells in the exponential growth phase, and stimulate it by the sporulating cells. Apparently, cAMP is not an effector of catabolite repression regulating exoprotease synthesis by the cells in the exponential growth phase, inspite of stimulating the enzyme synthesis at the background of easily metabolizable carbon sources. The same effect is produced by cAMP in the absence of additional carbon sources. AMP, adenine, GMP and guanine exhibit a similar action on the enzyme synthesis; the effect is most pronounced in the medium without easily metabolizable carbon sources. The action of cGMP is specific: cGMP inhibits the synthesis of exoprotease in the presence of additional carbon sources, and stimulates it in the absence of easily metabolizable compounds.

[Relationship between spore formation and exoproteinase synthesis in Bacillus thuringiensis]. / O zavisimosti mezhdu sporoobrazovaniem i sintezom ékzoproteinazy u Bacillus thuringiensis.

The localization of exoproteinase in the conventionally "periplasmic" space of Bacillus thuringiensis was established. The enzyme located at the outer surface of the membrane was found, in the course of sporogenesis, within the spore where it could fulfill various functions. The role of glutamine synthetase was determined in the regulation of exoproteinase synthesis and sporogenesis. The both processes were inhibited in the conditions suppressing the activity of glutamine synthetase.

[Morphologic heterogeneity under different conditions of living and destruction in Anabaena variabilis cyanobacteria]. / Morfologicheskaia geterogennost' pri razlichnykh usloviiakh zhizni i destruktsii tsianobakterii Anabaena variabilis.

The proportion between various morphological forms of the cyanobacterium Anabaena variabilis was studied under different conditions of its growth and destruction. When the cells lost viability at the stationary phase of cultural growth under the optimal conditions of illumination (1500--2000 lx), in the dark or when nitrogen was deficient, the filaments became shorter (4 to 2.2 cells per filament on the average), the cells larger, 4.5x6 microns). Under the conditions of nitrogen deficiency, the content of phycocyanin sharply decreased as well as that of chlorophyll. "Aging" under the conditions of optimal illumination was accompanied with "weighting" of the cells at the prolonged stationary phase and a gradual decrease in the content of phycocyanin and chlorophyll. When the cells were exhausted in the dark, the content of protein, RNA and phycocyanin decreased while that of chlorphyll hardly changed for a considerably long period of time. The most versatile morphological heterogeneity, when the cells were rapidly destroyed under the conditions of high light intensity, was as follows: both larger and more spherical as well as smaller and longer than in the control cells was found and catenuate cells were detected. The colour of the culture was light-brown or blue. When grown in a medium containing aspartic acid, the culture consisted of long filaments (ca. 18 cells per fragment instead of 4 cells in the control).