Evaluation of the Effectiveness of Metabolites of Bacterial Strains Bacillus thuringiensis against Human Influenza Virus A/Aichi/2/68 (H3N2) In Vitro and In Vivo.

The morphological and physiological characteristics of Bacillus thuringiensis strains were analyzed and conditions for obtaining culture fluid with maximum yield of secreted RNases were determined. Zymographic analysis showed that culture fluid of B. thuringiensis strains along with low-molecular-weight (15-20 kDa) RNases contained enzymes with a molecular weight ~55 kDa and their content depended on the duration and conditions of culturing. Preparations based on B. thuringiensis culture fluid were effective against human influenza virus A/Aichi/2/68 (H3N2). In experiments on mice infected with 10 LD50 influenza virus strain A/Aichi/2/68 (H3N2), we selected effective variants of preparations based on culture fluid of B. thuringiensi strains for preventive administration that provided reliable protection of infected animals (protection coefficient 50%), close to that of the reference drug Tamiflu.

Study of Antiviral Activity of Metabolites of a New Serratia species K-57 Strain.

The results of studies of a newly isolated Serratia species K-57 strain are presented. The strain is characterized by antiviral activity towards human influenza A/Aichi/2/68/H3N2, vaccinia, mouse smallpox, and herpes simplex-2 viruses. The detected characteristics of the strain, including the data on activities on nucleolytic enzymes, recommend it for the development of therapeutic and preventive antiviral drugs.

[Theoretical and experimental study of the effect of membrane pores on spectra of amplitudes of polarization of a cell].

Spectra of amplitudes of polarization of erythrocytes, yeast cells, and latex particles in the range of 1-10 Hz were investigated by the method of dielectrophoresis. Positive dielectrophoresis of erythrocytes and yeast cells the frequency range of 60 - 100 Hz was revealed. The theoretically positive dielectrophoresis was evidenced by the occurrence of channels across the cell membrane and bacterial cell wall.

[The new eubacterium Roseomonas baikalica sp. nov. isolated from core samples collected by deep-hole drilling of the bottom of Lake Baikal].

Microbiological analysis of samples of sedimentary rocks from various eras of the geological history of the Baikal rift has enabled us to isolate a large number of microorganisms that can be classified into new, previously undescribed species. The present work deals with the identification and study of the morphological, biochemical, and physiological properties of one such strain, Che 82, isolated from sample C-29 of 3.4-3.5 Ma-old sedimentary rocks taken at a drilling depth of 146.74 m. As a result of our investigations, strain Che 82 is described as a new bacterial species, Roseomonas baikalica sp. nov., belonging to the genus Roseomonas within the family Methylobacteriaceae, class Alphaproteobacteria.

[Genomic and phenotypic analyses of microorganisms isolated from the sediments of Lake Baikal].

Genetic and biochemical methods and morphological examination were used to study microorganisms isolated from samples of deep drilling of the Lake Baikal bottom sediments. Based on blot hybridization patterns, the strains investigated were divided into several groups according to the degree of homology of their genomic DNA. Morphological, biochemical, and ultrastructural characteristics of bacterial strains are described, and their compliance with the genomic analysis data is demonstrated.

[Preparation of lymphotoxin and properties of it]. / Poluchenie limfotoksina i izuchenie ego svoistv.

The process of isolation of highly purified human lymphotoxin was studied and optimized. A set of methods providing an increase in the content of the target product in the biomass (plasmid DNA amplification and selection of clones of transformed cells) was applied at the stage of cultivation. A two-step purification scheme (ion-exchange chromatography on DEAE-Biotone A1 and hydroxylapatite) was developed. A number of physical characteristics were studied.

[Biosynthesis of alpha2-interferon and tumor necrosis factor at different stages of culturing]. / Issledovanie biosinteza alpha2-interferona i faktorov nekroza opukholei na stadiiakh kul'tivirovaniia.

Study of the biosynthesis of human alpha 2-interferon and tumor necrosis factor in derivatives of E. coli SG200-50 recipient strain containing pIF16, pTNF311, and pLT21 plasmids demonstrated elimination of the plasmids from the cells without degradation thereof in the course of culturing. Methods increasing the content of the end products in the biomass are proposed.

[BME 361 I--a new site-specific deoxyribonuclease type II from Bacillus megaterium 361]. / BME 361 I--novaia sait-spetsificheskaia dezoksiribonukleaza II tipa iz Bacillus megaterium 361.

Bme 361 I, a new site-specific type II deoxyribonuclease, was purified from Bacillus megaterium 361 by chromatography on phosphocellulose P 11 and hydroxylapatite. The enzyme recognizes and cleaves the nucleotide sequence 5'-GG decreases CC-3' in double-strand DNA. Thus it is a true isoschizomer of deoxyribonucleases Hae III and BspR I.

[Restriction endonucleases: the detection of new producer strains and the isolation of enzyme preparations]. / Endonukleazy restriktsii: vyiavlenie novykh shtammov produtsentov i poluchenie fermentnykh preparatov.

The method for analysis of microorganisms for the presence of the modification-restriction systems has been developed. The method has permitted to detect more than 10 new producing strains of restrictases including microorganisms of Rhizobium genus. Some of them are promising for practical use. It has been shown that using selection of clones the strain productivity can be increased. The purification process for the majority of restrictases has been proposed. Some physical and catalytic properties of new enzymes have been studied.

[Site-specific restriction endonuclease RME211 from Rhizobium meliloti]. / Saitspetsificheskaia éndonukleaza restriktsii RME211 iz Rhizobium meliloti.

A new site-specific restriction endonuclease Rme211 from Rhizobium meliloti has been shown to recognize the following nucleotide sequence 5'-ATCGAT-3' in the double-stranded DNA. Thus, the enzyme is a true isoschizomer for restriction endonucleases Bsu151 and ClaI.

[Effect of poly(dA).poly(dT) sequence inserted into EcoR1 site of pBr322 plasmid on the expression of tet and bla genes]. / Vliianie posledovatel'nosti poli(dA).poli(dT), vstroennoi v EcoR1-uchastok plazmidy pBR322, na ékspressiiu genov tet i bla.

The 99 base pair poly(dA).poly(dT) stretch was inserted into EcoRI site of pBR plasmid. The effect of this insertion on tet-gene expression from P2 promoter, and bla-gene expression from P1 and P3 promoters was studied. The insertion results in a slight enhancement of the resistance of the cells to tetracycline and a decreased sensitivity to ampicillin. It is suggested that these findings reflect the effect of insertion on the transcription of the corresponding genes.

[Effect of adenine, adenosine and adenylic nucleotides on the mutagenic action of hydroxylamine]. / Vliianie adenina, adenozina i adenilovykh nukleotidov na mutagennoe deistvie gidroksilamina

The effect of some adenyl precursors of DNA synthesis on the mutagenic activity of hydroxylamine (HA) is studied. It is shown that the addition of adenine to a suspension of Escherichia coli B cells increases the yield of mutants by more than two times as compared with HA alone. The effects of adenosine, AMP and dAMP are somewhat different. It is suggested that the increase of the HA mutagenic effect produced by the addition of adenine may be due to: 1) the excess of the amount of adenylic precursors of DNA synthesis over guanilic ones, which promotes the erroneous base-pairing during the replication of the HA modified template; 2) the modification of adenylic precursors by HA into N6-oxy-dATP, and their incorporation into DNA. The mutagenic effect of N6-hydroxyadenosine, the product of the adenine modification by HA, in E. coli B pur- was studied. The experiments showed that N6-hyrdoxyadenosine induced about 1% of mutations, a relatively low lethal effect (the cell survival was 80%), and provided a high mutagenic action of this compound.

[Effect of adenine, adenosine and adenylic nucleotides on the mutagenic effect of hydroxylamine]. / Vliianie adenina, adenozina i adenilovykh nukleotidov na mutagennoe deistvie gidroksilamina

The effect of some adenyl precursors of DNA synthesis on the mutagenic activity of hydroxylamine (HA) is studied. It is shown that the addition of adenine to a suspension of Escherichia coli B cells increases the yield of mutants by more than two times as compared with HA alone. The effects of adenosine, AMP and dAMP are somewhat different. It is suggested that the increase of the HA mutagenic effect produced by the addition of adenine may be due to: 1) the excess of the amount of adenylic precursors of DNA synthesis over guanilic ones, which promotes the erroneous base-pairing during the replication of the HA modified template; 2) the modification of adenylic precursors by HA into N6-oxy-dATP, and their incorporation into DNA. The mutagenic effect of N6-hydroxyadenosine, the product of the adenine modification by HA, in E. coli B pur- was studied. The experiments showed that N6-hydroxyadenosine induced about 1% of mutations, a relatively low lethal effect (the cell survival was 80%), and provided a high mutagenic action of this compound.

[The influence of adenine, adenosine and adenylic nucleotides on the mutagenic action of hydroxylamine]. / Vliianie adenia, adenozina i adenilovkh nukleotidov na mutagennoe deistvie gidroksilamina

The effect of some adenyl precurosors of DNA synthesis on the mutagenic activity oh hydroxylamine (HA) is studied. It is shown that the addition of adenine to a suspension of Escherichia coli Bcells increases the yield of mutants by more than two times as compared with HA alone. The effects of adenosine, AMP and dAMP are somewhat different. It is suggested that the increase of the HAmutagenic effect produced by the addition of adenine may be due to:1) the excess of the amount of adenylic precursors of DNA synthesis over guanilic ones, which promotes the erroneous base-pairing during the replication of the HA modified template; 2) the modification of adenylic precursors by HA into N6-oxy-dATP, and their incorporation into DNA. The mutagenic effect of N6-hydroxyadenosine, the product of the adenine modification by HA, in E. coli Bpur- was studied. The experiments showed that N6-hydroxyadenosine induced about 1% of mutations, a relatively low lethal effect (the cell survival was 80%), and provided a high mutagenic action of this compound.