[Transduction as one of the methods of obtaining genetic information in Erwinia].

Transduction is one of the key processes of horizontal transfer of genes in bacteria. It is known that it is involved in distribution of the main factors of pathogenicity among numerous enterobacteria. It is shown that clear mutants and some variants of the temperate bacteriophage ZF40 Erwinia carotovora subsp. carotovora can perform general transduction of chromosome and plasmid genes of the bacterium E. carotovora. The indicators of chromosome transduction frequencies of the markers--arg+, met+, trp+, ura+ have a broad range of values: 7.10-10(-8) - 1.1-10(-1). The authors have succeeded in increasing the transduction efficiency due to infecting the recipient bacteria on the solid medium LB. Such approach is important for the phages similar to ZF40 in which adsorption is accompanied by re-adsorption of phage particles. The mechanism of transfer of bacterial genes by the type of general transduction is connected with cyclic permutation of phage DNA.

[Characteristics of lysogenic induction of bacteriocins in thymine mutants of Erwinia carotovora].

Peculiarities of lisogenic induction of bacteriocins in thymine-dependent mutants of Erwinia carotovora subsp. carotovora have been studied. It was shown for the first time that availability of carotovoricins of two (and above) types characterized the defect polylysogeny of strains of different geographic origin. Use of various methods of induction of Thy--mutants or inducing agents of different nature leads to a selective accumulation of carotovoricins of certain types in the cell lysates. Results of the conducted investigations create preconditions for estimating an ecologic part of the defect lysogeny and bacteriocynogenicity for the important phytopathogenic bacterium E. carotovora.

[The study of Erwinia carotovora bacteriocins in the nalidixic acid resistant Erwinia carotovora]. / Izuchenie bakteriotsinov Erwinia carotovora s pomoshch'iu bakterial'nykh indikatorov, ustoichivykh k nalidiksovoi kislote.

A novel approach is proposed for the study of the macromolecular bacteriocins of Erwinia carotovora (MCTVs). The approach lies in that the bacteriocinogeny of pectolytic erwinia is studied using a lawn of a bacterial mutant resistant to nalidixic acid, an inducer of MCTVs. The high efficiency of this approach was demonstrated by studying carotovoricins in 104 different E. carotovora strains, 88% of which bear MCTVs, distinguished by the morphology of zones of induced lysis on a lawn of susceptible cells, the lysis pattern, and some other characteristics. Preliminary studies by this approach showed that there is no correlation between the occurrence of MCTVs in particular E. carotovora strains and the habitat of the host plants from which these strains were isolated. There are grounds to believe that the approach proposed can also be used for investigating bacterial lysogeny.

[Comparative study of properties of temperate erwiniophages 49 and 59]. / Sravnitel'noe izuchenie svoistv umerennykh érviniofagov 49 i 59.

Molecular-biological properties of two relative temperate erwiniophages 49 and 59 have been comparatively studied. The both phages are highly specific with respect to sensitive bacteria and lyse only inconsiderable quantity of amylovora-like strains of Erwinia horticola. It has been established that erwiniophages are distinguished by the basic parameters of a single reproduction cycle in the cells of common host E. horticola 450. Considerable differences between phages have been also found in the areas of genomes responsible for the establishment and maintenance of lysogenic state in the cells of the bacterium-host. Study of structure polypeptides has confirmed the identity of capsids and tails of phages 49 and 59. It has been shown that phage 49 has another, as compared to phage 59, basal plate, which availability destabilises the phage tail and leads to virion destruction under various physical effects. Virion DNA of phages 49 and 59 are of the same size--47.9 kbp, but differ as to GC-content. Using the restriction analysis it has been shown that genome of phage 49, as well as the genome of phage 59, is permuted, but its permutation is of discrete character. The fact of recombination interaction between erwiniophages 49 and 59 has been established. It is supposed that phage 49 is the recombination (hybrid) derivative of phage 59 and unknown phage, or prophage, genetic module. The given recombination, probably, took place under the persistence of different phages in the general polylysogenic system of E. horticola.

[Isolation of highly active strain producing the antistaphylococcal antibiotic batumin]. / Poluchenie vysokoaktivnogo shtamma--produtsenta antistafilokokkovogo antibiotika batumina.

The use of chemical and UV-induced mutageneses allowed us to increase the biosynthetic activity of the strain capable of producing new antistaphylococcal antibiotic, batumin. The strain of Pseudomonas batumici N17 producing 87-100 mg batumin per liter culture liquid was selected. Its activity was 3.5-5 times higher than the activity of the most potent natural strain. P. batumici N17 was shown to be stable in relation to the synthesis of batumin.

[Factors that affect transduction in microorganisms]. / Faktory, vliiaiushchie na transduktsiiu u mikroorganizmov.

Data from literature concerning general and specialized transduction in microorganisms are given in the paper. The process of exogenic DNA penetration to the cells of bacteria and participation of protein products of separate phage genes in this process are described. The so-called E-proteins in a set with DNA penetrate through a cell membrane. In phage P22 they are protein products of phage genes 7, 16, 20. In P22 mutants with an altered transducing frequencies (HFT and LFT) the due functions are also coded by the phage genes. It is shown that the process of DNA packing in phages P22, phi 80, lambda and others is genetically determined. The gene transfer frequency depends on UV radiation and the very nature of transducing phages itself. In virulent phages the UV radiation up to inactivation level 95-99% evokes a decrease of their "killer" ability, which is accompanied by an increase of survivability of the formed transductants and, as a result, by enhancement of the transduction transfer frequency. An important role of the transduction analysis for fine mapping of a genome of microorganisms and its significance for practice are shown. A mathematical analysis of the data on cotransduction of linkage markers is presented as such that may be used when determining the value of transduced fragment of a chromosome.

[Plasmid R68.45 and S-a transduction by the temperate bacteriophage 59 of Erwinia carotovora 268]. / Transduktsiia plazmid R68.45 i S-a umerennym bakteriofagom 59 Erwinia carotovora 268.

Temperature bacteriophage 59 of Erwinia carotovera 268 had transduced extrachromosomal DNA: plasmids of R68.45 and S-a. Before plasmid transduction experiments the suitable donor strains of indicator culture Erwinia horticola 450 harbouring R68.45 and S-a were created. The frequency of plasmid R68.45 transfer from Pseudomonas putida to E. horticola 450-8 by conjugation was equal to 5 x 10(-8) per a donor cell and in the case of S-a--from E. coli C600 for the same recipient cells--was 2 x 10(-6). Bacteriophage 59 has transduced only separate markers of plasmid R68.45, since plasmid S-a is probably transduced by the phage as an intact unit.

[Mapping of the c-region of the temperate phage 59 of Erwinia carotovora 268]. / Kartirovanie c-oblasti umerennogo faga 59 Erwinia carotovora 268.

The present communication deals with the genetic mapping of the temperate bacteriophage 59 immunity region. Morphological mutants of the c-type of the temperate bacteriophage 59 were isolated after UV-treatment of the phage. Complementation analysis of 36 c-mutants has shown that the bacteriophage 59 c-region consists of at least four genes responsible for the establishment of lysogenization. The two-factor crosses were used to determine the mutual positions (order and distances) of the c-mutations. The order of the c-genes is C1--C3--C2--C4. The three c-genes are localized in a short region of the phage 59 chromosome, but the fourth gene is located in the separate locus.

[Characteristics of transduction in Erwinia by phage 59]. / Osobennosti transduktsii érvinii fagom 59.

A temperate bacteriophage 59 from polylysogenic strain Erwinia carotovora 268 transduces the following genetic markers: arg+, ilv+, leu+, met+, thr+, thy+, trp+, ura+. The transduction frequencies varied from 1 x 10(-8)- to 1 x 10(-6) and dependent on the multiplicity of infection, UV-irradiation of transducing bacteriophage, the nature of phage lysates. The characteristics of single transductants have been studied. Analysis of the obtained results suggests bacteriophage 59 to perform the generalized transduction.