[Cloning and expression of bacteriophage FMV lysocyme gene in cells of yeasts Saccharomyces cerevisiae and Pichia pastoris].

Cloning, sequencing, and expression of the gene for soluble lysozyme of bacteriophage FMV from Gram-negative Pseudomonas aeruginosa bacteria were conducted in yeast cells. Comparable efficiency of two lysozyme expression variants (as intracellular or secreted proteins) was estimated in cells of Saccharomyces cerevisiae and Pichia pastoris. Under laboratory conditions, yeast S.

[Using adaptive mutagenesis system for identification of early genes encoding de novo purine biosynthesis in methylotrophic yeast Pichia methanolica MH4].

A collection of spontaneous "Roman's mutants" (1654 mutants) for early genes of purine biosynthesis PUR1-PUR5 was obtained from 16 parental ade1(pur6) and ade2(pur7) strains of the methylotrophic yeast Pichia methanolica. Two genes, bifunctiional ADE7,4(PUR2,5) and ADES(PUR4), were identified earlier. For identification of the two remaining early genes (ADE3 and ADE8), a novel approach was used: a comparison of spectra of spontaneous Roman's mutants and relative sizes of genes (with regard to the length of polypeptides in amino acid residues).

[Comparison of genotypic and biochemical characteristics of Streptococcus thermophilus strains isolated from sour milk products].

Overall, 72 strains of lactic acid thermophilic streptococci isolated from sour milk products manufactured in various regions of Russia and European countries were analyzed using classical microbiological and molecular biological methods. Physiological and biochemical properties and genetic diversity of these Streptococcus thermophilus strains were studied, and a comparative analysis of the nucleotide sequences of the 16S rRNA gene was conducted. It has been demonstrated that the homology of proximal parts of the 16S rRNA gene of all the strains studied towards one another and towards the reference strain ATCC19258 amounts to 100%.

[Comparative analysis of genome sizes in Streptococcus thermophilus strains].

Twenty-five Streptococcus thermophilus isolates were analyzed using pulse-field gel electrophoresis (PFGE) and gene restriction profile analysis techniques. 16S rRNA gene sequences of the isolates were almost 100% homologous. However, genomic fingerprinting analysis has shown variability in both genome size and restriction fragments length.

[Genetic diversity of the natural strains of Streptococcus thermophilus].

The method of RAPD-PCR and comparative analysis of the PCR fingerprinting profiles similarity was used to characterize interspecific diversity of natural isolates of the lactic acid bacteria Streptococcus thermophilus. The strain genetic diversity was demonstrated using three primer variants, designed for different bacterial genome regions. The resolution of RAPD-PCR technique with different primers for identification at the species level and for certification at the strain level, was examined relative to the commercially important cultures of S.

[Identification of industrial strains of lactic acid bacteria by methods of molecular genetic typing].

Various methods currently used in microbiology for determining taxonomic state of bacteria are discussed. The main focus is aimed at identifying and gene typing of lactic acid bacteria, used as starter cultures for industrial process of production of sour milk products, meat products, and probiotics.

[Bvg-negative regulation of repeated sequence transferring in Bordetella pertussis cells].

A method of monitoring the sequential events of IS481 transposition into the ctag site of bvg operon of Bordetella pertussis has been developed. Reproduction of virulent B. pertussis cells in vitro is accompanied by intrachromosomal site-specific IS481 transposition, which, in turn, results in inactivation of bvg operon of the causative agent and cell avirulent state.

[Use of methylotrophic bacteria Methylobacillus flagellatum KT for isolation of deuterated exogenous carbohydrates].

The cultivation conditions optimal for biosynthesis of exogenous polysaccharides by methylotrophic bacteria Methylobacillus flagellatum were evaluated. The mutant strain most active in accumulating exogenous polysaccharides was selected. Gradual adaptation of this strain to the deuterated medium containing 1 vol % CD3OD in deuterium oxide intensified biosynthesis of exogenous polysaccharides and inhibited bacterial growth (compared to the standard medium).

[Design of the human GM-CSF gene using the polymerase chain reaction and its expression in Pseudomonas putida cells].

Construction of human GM-CSF gene was conducted by the PCR technique. Four exons of GM-CSF gene were synthesized on the basis of human blood DNA using thermostable Tth DNA polymerase. Synthetic oligonucleotides were used as primers.

[The effect of amino acids in the asparagine family on the aspartate kinase and homoserine dehydrogenase of ethionine-resistant mutants of Pseudomonas putida].

The activity of aspartate kinase and homoserin dehydrogenase from ethionine resistant mutants Pseudomonas putida 25 and 6 have been studied as affected by amino acids from the family of asparagine. They are characterized by a capacity to the surplus synthesis of methionine. It is shown that mutants have negative regulation of the level of activity of the studied enzymes.

[Localization of prophage SM of Pseudomonas aeruginosa in the chromosome of host cells].

Pseudomonas aeruginosa PAO SM-prophage was localized on the chromosome between thr-9001 and pur-66 locuses on 42-43 min of chromosomal genetic map. The location of prophage was identified on the basis of prophage linkage with the above-mentioned markers and confirmed by the purine, hypoxanthine and threonine deletions in course of thermoinduction of SM cts6 prophage from lysogens. The decrease for two orders in lysogenization frequency of thr mutants by SM bacteriophage suggests the integration of SM prophage in these cells into some other region of chromosome.

[Characteristics of Methylobacillus flagellatum KT mutants, deficient for phosphoglucoisomerase, an enzyme of the ribulose monophosphate cycle of obligate methylotrophic bacteria].

The activities of the key enzymes of ribulose monophosphate cycle for formaldehyde oxidation and assimilation were tested in crude extracts from temperature sensitive mutants of obligatemethylotroph M. flagellatum KT. Two mutants deficient in phosphoglucoisomerase activity were identified during this screening.

[Temperature-sensitive mutant of the obligate methylotroph Methylobacillus flagellatum KT deficient in glucose-6-phosphate dehydrogenase].

The common approach is developed for isolation of mutants deficient in key enzymes of ribulose monophosphate pathway for formaldehyde oxidation and assimilation by obligate methylotrophic bacteria. The approach is based on total isolation of temperature sensitive mutants and their biochemical characterization. A number of ts- mutants of obligate methylotroph M.

[Genome organization of the plasmid of IncQ/P4 group and its vector derivatives].

The genome organization and functioning of IncQ/P4 plasmids are reviewed. Based on these plasmids, cloning vectors have been constructed for broad host range of gram-negative bacteria. Together with one- and two-replicon vectors for cloning via insertion inactivation of markers, specialized plasmid vectors are described: cosmids, promoter-probe vectors, vectors for direct selection of recombinant molecules.

[Control of lysogeny and a genetic map of the temperate phage SM of Pseudomonas aeruginosa].

76 mutants with impaired ability to lysogenize host cells were isolated in SM phage after mutagenesis using several chemical mutagens. By means of complementation test, these mutants were distributed into two groups, cI and cII. The mutants of the cI group were similar phenotypically to the cI mutants of phage lambda defective in synthesis of repressor.

[The effect of R-plasmids on the reproduction of Pseudomonas aeruginosa phage SM].

The inheritance of plasmids Rms163 and R74 by Pseudomonas aeruginosa strain PAO hs been shown to effect the reproduction of a temperature bacteriophage SM. The decrease in plating efficiency of bacteriophage on Pseudomonas aeruginosa PAO (rms163) lawn is explained by the high degree of cell lysogenization by bacteriophage. Plasmid R74 inhibits bacteriophage SM propagation ultimately, evidently due to interruption of definite stages in vegetative development of bacteriophage by the products of plasmid specific genes.

[Complementation and the physiological characteristics of the ts mutants of Pseudomonas aeruginosa phage SM].

Seventy three temperature-sensitive mutants of Pseudomonas aeruginosa SM phage have been obtained using different mutagens and assigned to thirteen complementation groups. Representative mutants of each group have been studied with the aim of characterizing tentatively the time of genes expression in infected bacteria. Two genes appear to function during the first minutes after infection, whereas the remaining genes are needed for late functions.

[Development of a system vector-host in methylotrophic bacteria].

Cloning of methylotropic and other Gram negative bacteria's genes was performed using vectors derived from IncP4 plasmids. Plasmids, such s RSF1010 are 8.8 kb in length, have a high copy number and broad host range and can be mobilized efficiently by a number of conjugative plasmids.

[Transducing activity of the temperate SM bacteriophage of Pseudomonas aeruginosa].

The temperate bacteriophage SM is not serologically related to the known transducing phages F116, G101, B3 of Pseudomonas aeruginosa. The strains with auxotrophic mutations within the wide ranges of the genetic map of P. aeruginosa strain PAO1 were used for studying the transducing activity of the SM phage.

[Transducing phages of Pseudomonas aeruginosa related to phage F116L].

New phages K104 and B26, which are relative to F116L by a number of biological characters, appeared to show general transducing activity. Phage K104 transduces all tested markers with higher frequency than the phage B26. Linkage of the bacterial markers pair ilv202--met28 durspectively.

[Isolation and general characteristics of a group of Pseudomonas aeruginosa temperate phages].

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).

[New lambdoid phages of Escherichia coli. II. Comparison of several genetic characteristics with lambda phages].

Functions of some newly isolated lambdoid phages and phage lambda genes were compared by their ability to interact with unrelated phages and the product of the bacterial gene gro P. 19 of 23 lambdoid phages studied interfere with prophage P2, that points out the presence of functionally active genes, essential for spi+ phenotype in their genomes. The development of 4 lambdoid phages with spi- phenotype is independent on the prophage P2 presence.