The crystal-forming strains of Bacillus laterosporus.

Bacillus laterosporus is a spore-forming bacterium characterized by its ability to produce a canoe-shaped lamellar parasporal inclusion, adjacent to the spore. In some B. laterosporus strains crystalline inclusions of various shapes and sizes, which are released separately from spores during the lysis of the sporangium, were also produced. The morphological characteristics of two crystal-forming strains, B. laterosporus BL 16-92 and LAT 006, were investigated.

[Structural and molecular-biological characteristics of a new transducing phage from Bacillus thuringiensis Tt 91]. / Strukturnaia i molekuliarno-biologicheskaia kharakteristika novogo transdutsiruiushchego faga Bacillus thuringiensis Tt 91.

A new bacteriophage Tt91 of larger size and broad lytical spectrum has been isolated from soil to widen the possibility to study new Bacillus thuringiensis strains. The Tt91 bacteriophage was shown to perform the intravariant transduction and, thus, can be used for genetic mapping. The ultrastructural analysis made it possible to refer bacteriophage Tt91 to morphotype A1 and showed similarity of Tt91 morphological structure to the one of CP-group bacteriophages. The performed comparative analysis of phage-specific proteins has confirmed a possible relation of the bacteriophages and revealed the differences between them. The data on the resistance of Tt91 DNA to majority of site-specific restriction endonucleases (17 out of 18 tested) and on DNA melting in the wide interval of temperatures suggests the presence of possible anomalies in the Tt91 DNA.

[Genetic properties of the nonflagellar Bacillus thuringiensis mutant]. / Geneticheskie svoistva bezzhgutikovogo mutanta Bacillus thuringiensis.

The nonflagellar mutant has been selected in Bacillus thuringiensis strain 33-69 var. galleriae. The absence of flagella in the mutant cells is confirmed by electron microscopy, by the specific "trench transit" test. The mutant preserved the biochemical characteristics of the parent strain, possesses the same phage sensitivity but lower sporulation ability. Fla+ phenotype is cotransduced with the His+ one in general transduction.

[Characteristics of Bacillus thuringiensis phages with circular permutation in the DNA molecule]. / Kharakteristika fagov Bacillus thuringiensis s tsirkuliarnoi permutatsiei molekul DNK.

Bacteriophages Tm2 and Tg27 of different origins but identical in biological properties have been compared. Physicochemical characteristics of bacteriophages have revealed the existence of end repeats and circular permutation of phage DNA. Phages Tm2 and Tg27 share the same dimensions of incapsulated DNA, differing in the sizes of phage genome and end repeats. Bacteriophage Tm2 genome is 45.2 kb. long with the end repeats containing 5.7%. The genome of Tg27 is 42.53 kb and 11.8% of end repeat. The bacteriophages relation has been confirmed by heteroduplex and restriction analysis. Tm2 and Tg27 share 84% of homology. Two regions of nonhomology are found representing a single-stranded loop and equishouldered vesicle with the sizes 2.19 kb and 5.03 kb, respectively.

Pseudomonas bacteriophage phi KZ contains an inner body in its capsid.

Electron microscopical examination of the new virulent bacteriophage phi KZ, specific for Pseudomonas aeruginosa, has revealed an unusual structure in its capsid. In the center of the phage head is a cylinder of low electron density ("inner body"), surrounded by fibrous material which is packed around the inner body in a spoollike manner. The inner body itself has a springlike appearance. These structures disappear after adsorption of phage particles to bacteria. Various morphological forms, which can be interpreted as intermediate steps in phi KZ DNA condensation, have been seen in ultrathin sections of phi KZ-infected cells.

[Electron microscope study of the intracellular development of the Pseudomonas aeruginosa bacteriophage phi KZ]. / Elektronno-mikroskopicheskoe izuchenie vnutrikletochnogo razvitiia bakteriofaga phi KZ Pseudomonas aeruginosa.

The study of the ultrathin sections of cells infected with virulent phage phi KZ has confirmed the presence of a specific cylindrical formation, an inner body, in the head of this phage and revealed the spiral structure of this inner body. The formation of DNA condensates whose structure resembles a spring wound around the core (the inner body) has been shown to occur in the cells in the process of the ultracellular development of phage phi KZ. This development leads to characteristic changes in the cellular structure, and in particular in the cell walls and the nucleoid.

[Lysogeny in Bacillus thuringiensis]. / Lizogeniia u Bacillus thuringiensis.

Different strains of several Bacillus thuringiensis serotypes were analyzed for lysogeny. All of the studied cultures released phages. Phages with an isometric capsid and a noncontractible tail were detected in preparations of the majority of the cultures. The growth of a group of related phages was limited upon lysogenization of the galleriae serotype with Tm2 phage isolated from a culture of the morrisoni serotype. The physico chemical parameters of the phages were determined.

[Electron microscopic study of the interaction between phages and Bacillus thuringiensis cells]. / Elektronno-mikroskopicheskoe i zuchenie vzaimodeistviia fagov s kletkami Bacillus thuringiensis.

The interaction of phages belonging to different morphological groups with the cells of Bacillus thuringiensis var. galleriae R and S variants was studied. No adsorption of phages Tg11 and Tg18 on the cells of R variant was found upon infection in a liquid medium. What is characteristic of phage Tg11 is that it is predominantly adsorbed at the poles of S variant cells. Phage Tg18 particles are uniformly distributed along the perimeter of S variant cells. Phage Tg13 is adsorbed on the both variant cells. Phage aggregates with the elements of cell walls having a tetrahonal assembly of the subunits can be revealed in phage Tg13 lysates. The size of the subunits is 7 nm and the distance between their centers is 11 nm. A structured element, apparently the T-layer, is involved in the adsorption of phage Tg13 on the cells.

[Bacteriocin-like factor in Bacillus thuringiensis]. / Bakteriotsino-podobnyi faktor Bacillus thuringiensis.

The paper describes Bacillus thuringiensis var. galleriae strains possessing a bacteriocin-like factor (factor K) which inhibits the cultures of a number of serotypes of Bac. thuringiensis. The K+ cultures exhibit no antibacterial effect on other gram-positive and gram-negative microorganisms. The maximal level of factor K is found by the 8--9th hour of cultivation. No correlation has been established between the strucutred elements in the preparations of K+ cultures and the antibacterial activity. Apparently, factor K can be transferred to other strains.

[Isolation and general characteristics of a group of Pseudomonas aeruginosa temperate phages]. / Vydelenie i obshchaia kharakteristika gruppy umernnykh fagov Pseudomonas aeruginosa.

Eighteen temperate phages were isolated from 38 natural strains of Pseudomonas aeruginosa. The phages belong to five heteroimmune groups according to the ability of lysogenic variants of the strains PAO1 and PAT2 to exclude the growth of the superinfecting phage. Phages of the II and V immunity groups are serologically similar; the remaining phages are not inactivated by antisera against phages B26 (II group) and K1338 (V group). Prophages of the II, IV, and V groups are induced by UV for vegetative growth. Phages belonging to different immunity groups vary in their morphology and particle size as was found by electron microscopy. Phages of the I, II, IV and V groups comprise one morphological type, those of the III group are of another morphological type. Phages of the IV group are not adsorbed on the bacterial mutants resistant to phages of the II and V immunity groups.

[Stucture of PhiKZ bacteriophage particles]. / Struktura chastitsy bakteriofaga PhiKZ.

The structure of the particle of a new bacteriophage Pseudomonas phiKZ was studied. The particle of phiKZ bacteriophage was shown to have some features distinguishing this phage from all those known heretofore: a large size of the head and DNA and the presence in the head of a special structural formation named the central body. The central has a cylindrical shape and may be isolated from the head of the phage by repeated freezing-thawing the phage preparation. The structure of the central body is complicated. Possible functions of the central body are discussed.

[Electron microscopic study of Bacillus subtilis mutants differing in the serine proteinase activity and spectrum]. / Elektronno-mikroskopicheskoe issledovanie mutantov Bacillus subtilis, otlichaiushchikhsia po aktivnosti i spektru serinovykh proteinaz.

Vegetative cells and spores of the colonial morphological mutants of Bacillus subtilis A-50 were studied by electron microscopy. The ultrastructure of vegetative cells from both asporogenic colonial-morphological mutants and those which were capable of forming spores in the presence of high concentrations of nitrogen and carbon sources with a decreased activity and a modified spectrum of serine proteases differed from the parent strain by the presence of a microcapsule, the uneven thickness of a cell wall, and the absence of a distinct periplasmic space. Crystalline inclusions of a regular shape were detected in the sporeforming mutant in those cells which were devoid of spores. Spores of the mutant had additional layers.

[Electron microscopic study of the cells of variants of Bacillus thuringiensis var. galleriae forming colonies with altered morphology]. / Elektronno-mikroskopicheskoe izuchenie kletok u variantov Bacillus thuringiensis var. galleriae obrazuiushchikh kolonii s izmenennoi morfologiei.

Colonial-morphological variants of Bacillus thuringiensis var. Galleriae were studied by electron microscopy. The S variant was found to be asporogenous, whereas the R variant produced mature spores. Morphological modifications in the cell were followed in the course of sporulation. Spores were shown to have thin filamentous and tubular protrusions which had not been so far described in crystalliferous bacteria. Preparations from colonies of the R variant contained peculiar structures which resembled phage tails. A possible function of these structures is discussed.

[Characteristics of phages of spore-forming bacteria isolated from the soil]. / Kharakteristika vydelennykh iz pochvy fagov sporoobrazuiushchikh bakterii.

Phages lyzing spore forming bacteria were isolated from soil, and their biological properties and fine structure were studied. The spectrum of lytic activity was determined as well as parameters of the intracellular phage growth. The burst size of the phage varies from 8 to 725 particles per infected cell, the latent period lasts 25-100 min for various phages. According to the data of electron microscopy, the phages are divided into three morphological groups. The phages Tg7, AR13 and BPP10 have a complex structure.

[Preliminary electron microscopic and x-ray study of the crystalline protein of diphtheria toxin]. / Predvaritel'noe élektronno-mikroskopicheskoe i rentgenovskoe izuchenie kristallicheskogo belka difteriinogo toksina

The authors present the results of the electron microscopic and roentgenological study of the crystalline protein of diphtheria toxin. On the basis of direct measurements of the crystal image and diffraction pictures it was possible to calculate the interplane distances of the placement of molecules in the crystal. Examination in polarization microscope showed that the crystals were optically uniaxial with a direct extinction and a positive character of elongation. Molecular aggregates revealed in the protein molecules resembled the caudal part of the bacteriophage by structure.