[Controlling flies on swine breeding farm complexes].
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Aerosols↗
Biomedical subjects
V D Kuznetsov
Publications and source records attributed to V D Kuznetsov.
[Lysis of the cellular walls of Streptococcus group A by enzymes produced by actinomycetes].
More than 80 cultures of actinomycetes belonging to different taxanomic groups were studied with a purpose of screening actinomycetes actively producing enzymes lyzing the cell walls of group A streptococci. 31 strains of the actinomycetes producing enzymes which lyzed the cell walls by 20-50 and 60-80 per cent within 1 and 4 hours respectively were selected. The proteolytic activity of the enzymes produced by these strains was also studied. It was shown that 4 cultures, i.e. Actinomyces albus, strains 6 and 9, Actinomyces levoris, strain 29 and Actinomyces gibsonii, strain 42 were of interest as organisms producing enzymes which lyzed the streptococcal cell wall without impairing its antigenic components.
Actinomycetales↗
[Optimization of the nutrient medium for the biosynthesis of albofungin by the steepest ascent procedure].
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Antibiotics, Antineoplastic↗
[Spontaneous variability of Actinomyces werraensis].
The study of spontaneous variation of Act. werraensis not subjected to the treatment with mutagens and stabilizing selection revealed 6 variants within the homologous series of hereditary variation of apigmental actinomyces. The example of revealing the proactinomycete-like variants in Act. werraensis confirmed the prognosticating principle of the homologous series law in the hereditary variation of actinomycetes. Correlation between the cultural and morphological features of the spontaneous variants and the antibiotic-production level was shown. It was found that the variants of Act. werraensis had a high variation coefficient characteristic of the wild type actinomycetes. A possibility of increasing the biosynthetic activity of Act. werraensis by selection of spontaneous variants with artificial mutagenesis was shown.
Anti-Bacterial Agents↗
[Severity of the work, the daily energy expenditures and nutrition of the workers laying the track in the construction of the Baikal-Amur main line].
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Adult↗
[Electron microscopic study of the structure of colonies of culture of Actinomyces parvullus producing actinomycin D].
Ultrafine structure of the mycellium of the colonies of active and non-active variants of Actinomyces parvullus, producing actinomycin D was studied. Functional rebuilding of the cells of the substrate and aerial mycellium during the colony development in connection with synthesis and accumulation of the antibiotic by the culture was shown. The process of production and secretion of an amorphous material in the cells of the substrate mycellium of the active variant of Actinomyces parvullus was studied. It was supposed that the above process was associated with the antibiotic synthesis by the organism cells. The phenomenon of intrahyphal growth of the hyphae observed in both the active and inactive variants of the colonies was rather characteristic of the cells of the culture studied.
Actinomyces↗
[Study of the population makeup and antibiotic and transamidinase activity of Actinomyces streptomycini 773 stored for a long period in a lyophilized, dried state].
Studies on variation of the streptomycin-producing organism Act. streptomycini 773 on its storage in lyophilized state showed that prolonged maintenance (for 8 years) resulted in increased percentage of "oligospore" (up to 6.9 per cent) and asporogenic (up to 6.0 per cent) variants in the population. The variants had lower transamidinase and antibiotic activity.
Actinomyces↗
[Study of the structure of colonies of active and inactive Actinomyces parvullus variants using luminescence and scanning microscopy].
The colony structure of the active and inactive proactinomycete-like variants of Actinomyces parvullus producing actinomycin D was studied with luminescent and scanning microscopy. Clear differentiation of the colony profile was shown by the structure and functions of the mycelium layers. A zone of active synthesis and accumulation of the antibiotic was observed in the colonies of the active variant in the upper part of the substrate mycelium with reddish-yellow self luminescence in UV light and characteristic close hyphae "cemented" by the intracellular substance. Formations of the granule type were often noted on the hyphae of that layer. The layer of the aerial mycelium was loosely connected with the substrate mycelium and consisted of sporophores and spore chains partially broken into single spores. The colonies of the inactive proactinomycete-like variant had a slightly differentiated profile with a sponge-like structure, no zones of the antibiotic synthesis being found. The presence of the intracellular substance was observed in the upper part of the colony supersubstrate mycelium.
Dactinomycin↗
[Effect of lyophilization methods on the formation of free radicals, the survivability and makeup of a population of the lincomycin producer].
It was shown that a short-time exposure of the spores of Act. roseolus 981 to air (oxygen) on their lyophilization by the chamber method resulted in formation of increased numbers of the free radicals in the lyophilized spores suspension and decreased the survival of the spores on their further storage under vacuum. The phenomena were less pronounced when the exposure of the spores to the air was excluded by using the collector method of lyophilization. This testified to the advantages of the latter method as compared to the chamber one. No effect of the lyophilization methods on the population composition of the spontaneous variants of Act. roseolus 981 was observed.
Cell Survival↗
[Review of the systematic position of Actinomyces orientalis (Pittenger et Brigham) Krass. 1970 and its reclassification as Proactinomyces orientalis (Pittenger et Brigham) comb. nov].
The micromorphology, growth cycle, chemical composition of the cell walls, and the susceptibility to lysozyme and specific phages were studied with the culture of Actinomyces orientalis RIA-1074. It is seggested on the basis of these studied to transfer the culture from the Actinomyces genus to the Proactinomyces genus and to rename it Proactinomyces orientalis (Pittinger et Brigham) comb. nov.
Actinomyces↗
[Use of the electron paramagnetic resonance method for the comparative evaluation of the effectiveness of the protective media used in the lyophilization of actimomycetes].
The accumulation of free radicals correlates with an increase in the percentage of killed lyophilized spores of actinomycetes. Therefore, the EPR method in combination with the method of "accelerated storage" at 37 degrees C was used to evaluate rapidly (during one month) the effectiveness and to select certain protective media for stabilization of actinomycetes cultures. The EPR method can be applied for comparative evaluation of only those media which did not contain originally free radicals.
Cryoprotective Agents↗
[Systematic position of an autotrophic actinomycete isolated from a floodplain marsh near Moscow].
A hydrogen-oxidizing actinomycete (Z-1046) was isolated from a flood-plain marsh in the Moscow Region. Its taxonomy was compared with that of similar cultures belonging to international special standards of actinomycetes (ISP). The strain Z-1046 was found to be identical with Streptomyces autotrophicus ISP-5011 (RIA-1008, ATCC-19727, CBS-466.68, IFO-12743). It has been also shown that the generic identification of the standard culture ISP-5011 is erroneous: as Hirsch (1960) holds, the culture belongs to the genus of Nocardia (Proactinomyces). Thus, the culture Streptomyces (Actinomyces) autotrophicus ISP-5011 must be eliminated from the international special standards of the genera Streptomyces and Streptoverticillium. The autotrophous actinomycete that we have isolated is classed as Proactinomyces autotrophicus comb. nov. (=Streptomyces autotrophicus Takamiya et Tubaki, 1956, ISP-5011, RIA-1008, ATCC-19727, CBS-466.68, IFO-12743, =Nocardia autotrophica, Hirsch, 1960).
Actinomycetales↗
[Systematic place of the act nomycetes of the Albidus Krassilnikov, 1970 group].
Detailed studies of the taxonomical characteristics and the complex of produced antibiotics made it possible to establish the identity of Actinomyces albus var. fungatus, Solovieva et Rudaya, 1959 and Actinomyces tumemacerans, Krassilnikov et Koveshnikov, 1962. Both organisms produce a complex of antibiotics comprising albofungin, albonursin, and a polyene antibiotic belonging to the group of tetraenes. The cultures do not belong to the group of verticillate actinomycetes as was believed earlier (Krassilnikov, 1970). The later name, Actinomyces tumemacerans, is more appropriate since the organism described under the name of Act. albus var. fungatus differs sharply from other representatives of Act. albus and therefore cannot be regarded as its variety (nomen confusum). Actinomyces sp. RIA-248 producing albofungin differs from Act. tumemacerans P-42 as well as from Act. albus var. fungatus RIA-247 by the complex of produced antibiotics and other taxonomic properties. Apparently, it should be classed as a new species.
Anti-Bacterial Agents↗
[Population composition of Actinomyces tumemacerans and Actinomyces albus var. fungatus].
The population analysis of Actinomyces tumemacerans and Actinomyces albus var. fungatus has revealed identical homologous series of spontaneous variants, this suggesting the genetical relationship of the cultures. Variants of the same type (basic, oligosporous, asporogenous and proactinomycete-like) are identical not only according to their individual properties (Kuznetsov, 1973) but also in total characteristics typical of the variants of a given species. Populations of the studied cultures comprise variants synthesizing several antibiotics, i.e. albofungin, albonursin and tetraene (basic and oligosporous variants), albofungin and tetraene (asprogenous green variants), as well as variants producing only one tetraene antibiotic (proactinomycete-like variants). Therefore, the population analysis based on the law of homologous series in hereditary variability of actinomycetes can be used as a new approach to the taxonomy of these microorganisms.
Anti-Bacterial Agents↗
[Clarifying the systematic position of Actinomyces erythraeus Waksman et Curtis 1916 and its transfer to the genus Proactinomyces].
Cell walls of Actinomyces erythraeus RIA-1387 were found to contain m-diaminopimelic acid, arabinose, and galactose (type IV of cell walls). The mycelium undergoes fragmentation during superficial and submerged growth, and is not susceptible, or only mildly sensitive, to the action of lysozyme. The colonies of Act. erythraeus have no horizontal layers. These data suggest that the organism was erroneously classed as belonging to the Actinomyces genus. It should be transferred to the Proactinomyces genus under the name of Proactinomyces erythraeus (Waksman et Curtis) comb. nov.
Carbohydrates↗
[Prognosing the viability of lyophilized Actinomyces parvullus spores based on the "accelerated storage" method].
A technique of "accelerated storage" was used to evaluate promptly the effectiveness of protective (suspension) media for lyophilization and further storage of spores of Actinomyces parvullus 99. The number of survived spores can be predicted using the Arrhenius diagram and the van't Hoff rule. Equine serum without a conserving agent was found to be the most effective protective medium for lyophilizing spores of Act. parvullus, as compared to such media as milk containing no fat or a mixture of 3 per cent solutions of gelatin and glucose.
Freeze Drying↗
[Chitinase formation by actinomycetes in deep cultures].
Actinomycetes were cultivated in the medium containing demineralized crab shells as a source of carbon. Chitinase was found in filtrates of the cultural broth of all 44 studied strains. The activity of the extracellular chitinase was determined both by decomposition of ground chitin (CHI-activity) and colloid chitin (CHI-activity). The ratio between CHI and CHX in filtrates of the cultural broth of the most active nine strains varied from one to two.
Actinomycetales↗
[Lytic enzymes produced by Actinomyces levoris].
The composition of the enzyme complex produced by Actinomyces levoris which exhibits lytic action on the cell walls of Streptococcus lactis was studied by gel filtration on Sephadex G-25, ion exchange chromatography and isoelectric focusing. The complex was found to contain at least seven enzymes having different isoelectric points and substrate specificity. The enzymes were divided into three groups. (1) The enzyme with pI 10.2 seems to be a specific glucosidase; it possesses a high activity of the cell wall lysis and lacks a proteolytic activity. (2) The enzymes with pI 9.2 and 9.0 are, apparently, specific lytic proteases; they display both lytic and proteolytic activities. (3) The enzymes with pI 10.0, 9.5, 5.7 and 4.2 are, presumably, non-specific lytic proteases; they have a low lytic activity and a high proteolytic activity.
Bacteriolysis↗