Mikrobiologicheskii zhurnal最新文献

Natural strains of bacteria of Bacillus and Pseudomonas genera able to destroy cyanides are obtained. Natural strain of Pseudomonas fluorescens B-5040 has a property to destroy high concentration of cyanides (100-200 mg/l) and does not lose the destructive activity in the systems with sufficiently high concentration of mercury (Na3ASO4) compounds (500 mg/l).

Streptomyces globisporus 1912 strain contains plasmid pSG1912 (11, 2kb) determining some phenotypic properties. The plasmid is able to exist and to provide for exhibition of these properties both in autonomous and integrated state. It is established that plasmid pSG1912 and constructed derivatives are stably inherited by cells of S. globisporus 1912 and heterologous hosts, and besides, molecular size and determined properties being retained.

Pathogenic properties (for warm-blooded organisms) of the industrial strain Agrobacterium radiobacter (strain 204) and toxicity of biofertilizer on its base--rhizoagrin--have been studied. It is established that the studied microorganisms are avirulent, nontoxic, nontoxicogenic and may be recommended for making biopreparations. The preparation rhizoagrin is not toxic for warm-blooded animals and may be used as an alternative of chemical mineral fertilizers.

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.

Some trichotecenic mycotoxins (verrucarine A, roridines A and H, T-2-toxin) have been studied for their antibiotic effect on a wide spectrum of the yeast cultures (761 strains). The studied substances differ both in their activity and the action character. The yeast strains promising for development of microbiological methods of indication and detoxification of mycotoxins have been revealed.

Peculiarities of phagocytosis of pathogenic, conditionally pathogenic ristic is given to antiphagocytic factors which permit some species of these processes with immunity are considered in the paper. A characteristic is given to antiphagocytic factors which permit some species of mycobacteria to avoid protective bactericidal reactions of mammals and to reproduce in phagocytes. Expression of mycobacterial virulence depends on the character of interrelations between the pathogen and cells of reticuloendothelial and immune systems. Interpretation of this mechanism is important in development of the methods of infection control and creation of efficient vaccines.

Active sulphate-reducing microorganism which belongs to the genus Pseudomonas has been distinguished and described. The culture is a facultative aerobe, optimum Eh is -170-180 mV. Pseudomonas sp. being cultivated under strictly anaerobic conditions sulphate-reduction proceeds more intensively than under aerobic conditions. This fact should be taken into account under treatment of industrial sewage.

Biological properties of 350 strains of Klebsiella pneumoniae isolated in newborns during the outbreak of intrahospital infection have been studied. Experimental infection with isolated strains of a similar plasmid profile is simulated, interrelation between the presence of plasmids and ability of the strain to induce generalized Klebsiella infection is shown. Pathological processes in the newborns with generalized infection and in animals with the reproduced experimental Klebsiella infection are shown to be similar in principle.

When studying sensitivity of Proteus mirabilis to bactericide effect of blood serum the resistance to alternative way of the complement activation was found in a number of strains. The population of cells with morphologically determinable changes of the surface structures resistant to bactericide effect of the serum is formed as affected by the blood serum of the culture P. mirabilis. Proteus proteases capable to inactivate the complement components are one of the factors of P. mirabilis resistance to bactericide effect of the complement.

A new envelope antigen C, specific for virulent strains of Francisella tularensis, was revealed by immunodiffusion analysis. In contrast to antigens A and P this antigen is common for Francisella and Brucella. C-antigenic lipid fraction was obtained by chloroform-ethanol (1:1) extraction of bacterial slime. This fraction contained carbohydrates (31.6%) without proteins and detected by TLC glycolipid, which proved glycolipid nature of C-antigen. Introduction of C-fraction or alive F. tularensis resulted in accumulation of C. precipitins in blood serum.