[Characterization of the fluorescent pigment pyoverdine Pm, produced by Pseudomonas putida bacteria]. / Kharakteristika fluorestsiruiushchego pigmenta pioverdina Pm, produtsiruemogo bakteriiami Pseudomonas putida.

It has been shown that under iron-limited conditions Pseudomonas putida M produces large amounts of the fluorescent pigment, pyoverdine Pm, which is a siderophore and exhibits antibacterial activity. The absorption spectrum for the pyoverdine Pm has two main peaks, at 230 nm and 400 nm, respectively. It was demonstrated that pyoverdine Pm molecule besides dihydroxyquinoline moiety has a peptide chain contain five amino acids: threonine, serine, lysine, hydroxyaspartic acid and N delta-hydroxyornithine in a molar ratio 3:2:1:1:1.

[Mapping of the locus encoding the bacteriocinogenicity trait in Erwinia chrysanthemi ENA49]. / Kartirovanie lokusa, determiniruiushchego priznak bakteriotsinogennosti u Erwinia chrysanthemi ENA49.

The bacteria Erwinia chrysanthemi ENA49 have been found to produce bacteriocin that is similar in structure to the tail fibers of bacteriophages and suppressing viability of a number of Erwinia, Pseudomonas and Xanthomonas strains. Genetic control of bacteriocin synthesis is determined by the determinants localized on the 68 min of chromosomal genetic map.

[Induction of bacteriocin synthesis in Erwinia cells]. / Induktsiia sinteza bakteriotsinov kletkami Erwinia.

The effect of UV light and mitomycin C as inductors of bacteriocins biosynthesis by Erwinia was studied. 46 strains of Erwinia were tested and the synthesis of bacteriocins was induced by irradiation with UV light only in 14 of them. The irradiation dose providing the highest increase of the bacteriocin titer was different for every strain. The survival of the strains ranged within 0.06 to 11.3 per cent. The time course of the bacteriocin synthesis induced by UV light in 9 strains of Erwinia was studied and it was shown that the process had common similar characteristics: gradual increasing of the bacteriocin titer immediately after exposure to UV light, reaching the maximum level 5-7 hours after incubation and its persisting for the subsequent observation period. Mitomycin indices bacteriocin production by the Erwinia strains tested only in individual cases, the character of the effect being dependent on the drug concentration and exposure time.

[Some properties of bacteriocins from Erwinia]. / Nekotorye svoistva bakteriotsinov Erwinia.

The following properties of eight bacteriocins produced by Erwinia strains were investigated: thermal stability, sensitivity to proteolytc enzymes and enzymes involved in nucleic acid catabolism, dialyzability through a cellophane membrane. Their molecular weight was also measured. The bacteriocins proved to be protein substances with a molecular weight of 17,000--33,000 that differed in their thermal stability and sensitivity to proteolytic enzymes.

[Bacteriocinogenic activity of strains of the genus Erwinia]. / Bakteriotsinogennaia aktivnost' shtammov roda Erwinia.

Antibacterial activity of 272 Erwinia strains was studied. It was found that 182 or 66.9 per cent of the strains were capable of producing spontaneously antibacterial substances belonging to the class of bacteriocins; 125 bacteriocynogenic strains were divided into 25 groups on the basis of their antibacterial spectrum similarity; 57 bacteriocynogenic strains were not included into any of these groups because of their significant heterogenicity with respect to the feature studied. It was shown that most of the strains inhibited viability of the bacteria of both its own and other species. Investigation of the antagonistic activity of the Erwinia strains with broad antibacterial spectra with respect to E. coli indicative for colicins gave negative results. The study of the Erwinia strains sensitivity to the antibacterial effect of the bacteriocynogenic cultures showed that 210 out of 272 cultures were sensitive to separate bacteriocins.