[Effect of chitosan oligomer on phage particles and reproduction of phage 1-97A in Bacillus thuringiensis culture]. / Vliianie oligomera khitozana na fagovye chastitsy i reproduktsiiu faga 1-97A v kul'ture Bacillus thuringiensis.

The causes of bacteriophage 1-97A inactivation by the chitosan oligomer with a polymerization degree of 15 and the influence of the oligomer on the phage reproduction in the culture of Bacillus thuringiensis subsp. galleriae, strain 1-97, were studied. The study of the inactivation kinetics showed that, in 1 h, virtually all chitosan was bound to the phage particles, causing, as evidenced by electron microscopy, DNA release from the phage head, destruction of the phage particles, and agglutination of the phage particles or of their tails in the region of the endplate. High-polymeric chitosan caused more pronounced destruction of the phage particles than the oligomer. It was established that chitosan prevented the production of complete phage particles. One of the mechanisms of such an influence may be the production in the presence of chitosan of phage particles devoid of DNA.

[Coliphages inactivation using chitosan derivatives]. / Inaktivatsiia kolifagov proizvodnymi khitozana.

The effect of chitosan fragments with different degrees of polymerization and the chemical derivatives of chitosan differing in the number of amino groups and total molecule charge on phages T2, T4, and T7 was studied. The interaction of chitosan with bacteriophage particles inactivated them to the extent dependent on the chemical properties of chitosan and its concentration. Phage T2 was found to be most susceptible to inactivation by chitosan. The polycationic nature of chitosan plays an important role in the inactivation of phages. It is assumed that the abnormal rearrangement of the basal plate of phages, the loss of long tail fibers, and probably, modification of the receptor-recognizing phage proteins may be responsible for the inactivation of coliphages by chitosan.

[Effect of chitosan derivatives on the development of phage infection in cultured Bacillus thuringiensis]. / Vliianie proizvodnykh khitozana na razvitie fagovoi infektsii v kul'ture Bacillus Thuringiensis.

The influence of chitosan fragments with different degrees of polymerization and some chemical chitosan derivatives on the infection of Bacillus thuringiensis by phage 1-97A was studied. It was shown that chitosan inhibits phage infection and inactivates phage particles. The extent of inhibition of phage infection inversely depended on the degree of polymerization of chitosan fragments. On the contrary, the extent of inactivation of phage virulence was proportional to the degree of polymerization. Chitosan derivatives did not inhibit the growth of bacilli. Deaminated chitosan derivatives at a concentration of 100 mg/ml efficiently inhibited phage reproduction, exhibiting no correlation between the degree of deamination and antiviral activity. The anionic derivative chitosan sulfate and N-succinate-6-O-sulfate did not inactivate phage, did not influence bacterial growth, and did not inhibit the process of viral infection.

[Effect of chitosan derivatives on the reproduction of Coliphages T2 and T7]. / Vliianie proizvodnykh khitozana na reproduktsiiu kolifagov T2 i T7.

The effect of chitosan derivatives with different degrees of polymerization and deamination, as well as of chitosan 6-O-sulfate and chitosan N-succinate-6-O-sulfate, on the reproduction of coliphages T2 and T7 in Escherichia coli and on the growth of this bacterium was studied. Chitosan derivatives decreased the yield of coliphages and exhibited bactericidal activity. The efficiency of inhibition of viral infection and the bactericidal activity of chitosan were found to be dependent on the degree of its polymerization. At the same time, there was no correlation between the degree of chitosan deamination and the extent of inhibition of viral infection. Anionic chitosan derivatives virtually did not possess antiviral or bactericidal activity. It is assumed that chitosan blocks some stages of phage reproduction. The decrease in the phage-producing ability of E. coli may also be due to the bactericidal effect of chitosan.

[Inhibition of phagolysis in a Bacillus thuringiensis culture by chitosan]. / Ingibirovanie khitozanom fagolizisa kul'tury Bacillus thuringiensis.

The ability of chitosan (poly-D-glucosamine) and two chitosan salts to prevent the phagolysis of Bacillus thuringiensis subsp. galleriae strain 1-97 was studied. Chitosan and its salts inhibited the productive infection caused by two nonrelated bacteriophages 1-97A and 1-97B and suppressed the culture lysis upon spontaneous prophage induction. The efficiency of inhibition depended on the chitosan concentration, medium composition, and bacteriophage type.

[Inhibition by chitosan of productive infection of T-series bacteriophages in the Escherichia coli culture]. / Ingibirovanie khitozanom produktivnoi infektsii bakteriofagov T-serii v kul'ture Escherichia coli.

The possibility of the use of chitosan aminopolysaccharide (poly-D-glucosamine) and its two salts--acetate and hydrochloride--to prevent phase infection of the Escherichia coli culture, strain B1, was studied. It was shown that chitosan inhibited productive infection caused by the bacteriophages T2 and T7, the efficiency of inhibition of both bacteriophages depending directly on the final concentration of chitosan in a medium. Neither chitosan nor its salts significantly prevented the growth of the bacterial culture.

[Electron microscope study of the serological relations of Bacillus thuringiensis phages]. / Elektronno-mikroskopicheskoe issledovanie serologicheskogo rodstva fagov Bacillus thuringiensis.

The kinetics of neutralization cross-reactions was studied with Bacillus thuringiensis subsp. galleriae 1-97 phages, and serological complexes were investigated using immunoelectron microscopy. The results of these studies have made it possible to locate both common and specific antigenic components of the phages.

[Structural characteristics of DNA of Bacillus thuringiensis phages]. / Strukturnye osobennosti DNK fagov Bacillus thuringiensis.

The spectral characteristics of DNA from two phages of the polylysogenic Bacillus thuringiensis subsp. galleriae culture 1-97 were studied. The typical parameters of melting and the negative reaction with formaldehyde are indicative of the double-helical structure of these DNAs. The phage DNAs differ in the molar content of nitrogen bases (32 and 38 mole% of GC) and in their distribution along the molecule. This distribution is uniform in the DNA of one phage whereas the other phage DNA is composed of heterological segments with a different nucleotide composition.

[Cleavage of DNA from 2 phages of Bacillus thuringiensis by EcoRI and HindIII endonucleases]. / Rasshcheplenie DNK dvukh fagov Bacillus thuringiensis éndonukleazami EcoRI i HindIII.

The DNA of two Bacillus thuringiensis phages was restricted by endonucleases EcoRI and HindIII and the electrophoretic distribution of the fragments in agarose gel was studied. EcoRI was shown to restrict the DNA of phage 1-97A into 8 fragments and the DNA of phage 1-97B into 12 fragments. Restriction with HindIII results in the formation of 22 and 9 fragments for phage 1-97A and phage 1-97B, respectively. The molecular mass of the DNAs determined by summing up EcoRI restricts is 80.87 MDa for phage 1-97A and 32.45 MDa for phage 1-97B.

[Bacteriophages T3 and T7: transcription-dependent mechanism of phage DNA transport into the cell during infection]. / Bakteriofagi T3 i T7: zavisimyi ot trankriptsii mekhanizm transporta fagovoi DNK v kletku pri infektsii.

The mechanism by which bacteriophage T3 DNA is transported into the E. coli cell during infection was studied. The data obtained testify that bacteriophage T3, similarly to what we have earlier found for bacteriophage T7, introduces its DNA into the infected cell is a transcription-dependent way. A detailed discussion is presented on the occurrence of the transcription-coupled transport of viral DNA into the infected cell and on a number of general issues concerning the transport functions of template-directed enzymes.

[Comparative study of the physicochemical and biological properties of Bacillus thuringiensis phages]. / Sravnitel'noe izuchenie nekotorykh fiziko-khimicheskikh i biologicheskikh svoistv fagov Bacillus thuringiensis.

Two phages of the polylysogenic Bacillus thuringiensis subsp. galleriae 1-97 culture differ in the morphology of their particles. A comparative study of their antigenic properties has shown the possibility of cross serological reactions of neutralization with antiphagal sera. The results imply that there is an antigenic relationship between these phages. The data indicate that the nucleic acid component of the both phages is DNA. The sensitivity of phage 1-97 A to some physical factors has been studied.

[Polylysogeny in Bacillus thuringiensis var. Galleriae cultures]. / O polilizogenii kul'tur Bacillus thuringiensis var. galleriae.

The culture of Bacillus thuringiensis var. galleriae was shown to be polylysogenic. As has been found earlier, the culture has a phage with the original structure of particles whose tail possesses a special substructure called a "collar". The phage was described in detail as a phage of Bac. thuringiensis 1-97 with a "collar". Further studies of the culture of Bac. thuringiensis var. galleriae 1-97 has shown that it also contains another phage which differs sharply from the first one in the morphology of particles, the spectrum of lytic action, and other properties. Electron microscopy of the cultural fluid of the Bac. thuringiensis var. galleriae cultures has revealed in them the presence of different amounts of the particles of both morphological types found in the strain 1-97. These data suggest that the cultures of Bac. thuringiensis var. galleriae are polylysogenic. The methods for the isolation of the new phage are described.