PubMed Health⌕ Search

Biomedical subjects

N V Koltukova

Publications and source records attributed to N V Koltukova.

At least 19 recordsLinked to original sources
PubMedDate not supplied

[The identification of freshly isolated strains, the causative agents of human candidiasis and the search for effective antifungal probiotics].

The species variety of yeasts of the genus Candida in children and patients with AIDS has been investigated. Composition of the studied species was found to be similar in newborns and in women with candidiasis. In order to create new probiotics with antifungal properties, the cluster analysis of antagonistic activity of some Bacillus strains against Enterobacteriaceae, Candida, normoflora and food-fermenting lactobacteria has been conducted. There were selected the combinations of some Bacillus strains, which effectively inhibited pathogenic and opportunistic microorganisms and at the same time had no effect on intestinal normoflora.

AIDS-Related Opportunistic Infections↗
PubMedDate not supplied

[Use of associative cultures of cyanobacteria for tertiary treatment of sewage from yeast and alcohol plants].

The associative cultures of cyanobacteria were selected which may be used for development of technology of tertiary treatment of sewage for yeast and alcohol production plants. Growth parameters of associations were studied during periodic and continuous cultivation. When studying the influence of flowing speed for some exponents of treatment it was shown that cultivation of cyanobacteria should be carried out with the change of volume not more than 0.01 h. Final treatment 0.010 h-1 in order to return sewage to natural water reservoirs may be carried out by means of Oscillatoria sp. in bioponds.

Cyanobacteria↗
PubMedDate not supplied

[Comparative characteristics of physico-chemical and regulating properties of aspartate kinases from three species of cyanobacteria].

Aspartokinases have been isolated from the cell-free extracts of Plectonema boryanum, Anabaena variabilis and Synechococcus cedrorum. Their physico-chemical characteristics and peculiarities of retroregulation by amino acids were studied. It has been shown that in P. boryanum cells aspartokinase reaction is catalyzed by only one enzyme, which is similar to the previously described bacterial origin enzymes. Three izoenzymes, which differ in their main properties and amino acids-effectors, have been founded in the cells of A. variabilis. One enzyme with aspartokinase activity, which differs from other cyanobacteria enzymes in some physico-chemical features has been founded in the cells of S. cedrorum.

Aspartate Kinase↗
PubMedDate not supplied

[Change of serological properties of museum strains of Shigella flexneri in different terms of storage].

The viability, purity, biological and serological properties of museum strains of Shigella flexneri which were kept in lyophilized state during above 30 years were studied. Primary serological characteristics were specified, it was established that type 2a is the predominant serotype independent of the years and regions of isolation. Some strains lost antigens as a result of the long-term preservation or reinoculation on agar media.

Freeze Drying↗
PubMedDate not supplied

[Property of collection strains and new isolates of Shigella sonnei].

The vital ability, serological properties, antibioticograms and biochemical properties of collection strains and new isolates of Shigella sonnei have been studied. It was ascertained that the determined factors are sufficiently variable, thus they cannot be used as the independent basis for the classification of pathogens.

Serotyping↗
PubMedDate not supplied

[The colicynogenic activity and anthibiotic sensitivity of collected and newly isolated strains of Shigella flexneri and Shigella sonnei].

Among the collection strains of S. flexneri 10.5; 5.5; 2.6; 2.6 and 7.9% of strains were resistant to ampicillin, tetracycline, ceftryaxon, cefasoline, chloramphenycol, respectively. The maximum number of R-determinants of one strain was 4. The strains resistant to cefalosporynes were not revealed; among newly isolated strains of this agent, these strains resistant to ampicilline, tetracycline and chloramphenycol made 20%. Among the collection and newly isolated strains of S. flexneri, isolated 50 and more years ago, the part of colicinogenic ones was 10%. And, on the contrary both for the collection and newly isolated strains of S. sonnei colicinogenic activity is specific biological property (above 80%). Correlation relation between two tested pathogenic factors, certain serovars and biovars of the agents, was not revealed.

Anti-Bacterial Agents↗
PubMedDate not supplied

[Various physico-chemical properties of the amylolytic complex from Bacillus mesentericus].

Some physico-chemical properties of the Bacillus mesentericus amylolytic complex were studied, and optimal conditions of starch hydrolysis (pH 7.5-8.0; 45 degrees C) were found. The half-life of amylases at 50 degrees was 75 min. The heat stability of the enzymes increased in the presence of Ca2+ ions. Amylase was stable at pH 7-9 and readily inactivated at pH below 6.0. By physical and chemical characteristics the complex was close to analogous preparations from Bacillus alkalophilic strains. Isoelectrofocusing revealed that the complex consisted at least of two amylolytic enzymes.

Amylases↗
PubMedDate not supplied

[Characteristics of hydrolase biosynthesis in Bacillus mesentericus grown on various media].

The dynamics of the consumption of major carbon and nitrogen sources and the biosynthesis of hydrolytic enzymes were studied in Bacillus mesentericus grown on semisynthetic media. Conditions were chosen that provide the obtaining of the culture liquid with predominantly proteolytic or amylolytic activity. The replacement of maltose with native starch resulted in more intensive accumulation of the biomass and hydrolytic enzymes, and in more rapid (by 3-5 hr) transformation from the logarithmic to the stationary growth phase.

Bacillus↗
PubMedDate not supplied

[Hydrolase biosynthesis by morphological variants of Bacillus mesentericus as dependent on the storage conditions].

A method used to prepare the inoculum (a strain of Bacillus mesentericus, a producer of a complex of hydrolytic enzymes) has been studied for its effect on the activity of proteinases and amylases under submerged cultivation in fermenters. Optimal conditions for the culture storage and inoculum cultivation are developed to obtain standard enzymic preparations.

Bacillus↗
PubMedDate not supplied

[Purification of Bacillus mesentericus proteolytic enzymes by affinity chromatography].

By means of affinity chromatography on Ovomucoid-Sepharose two proteinases hydrolyzing casein and elastin were isolated from the supernatant of the Bacillus mesentericus culture medium. The activity yield of proteinases was 100%. The characteristics of the purified enzymes were studied. It is demonstrated that B. mesentericus possesses several proteinases.

Bacillus↗
PubMedDate not supplied

[Aspartate kinase complex of Anabaena variabilis during the early period of development of cyanophage A-1].

Aspartate kinase activity in cells of A. variabilis has been studied in the dynamics of development of virus infection. An early period of reproduction of cyanophage A-1 has been determined to be conjugated with the increase of biosynthesis of amino acids from aspartate family. Five isoenzymes of aspartate kinase were isolated and purified from A. variabilis cells during early development period of cyanophage A-1. Physicochemical properties and influence of amino acids of aspartate family on the activity of homogeneous isoenzymes have been studied. Retroinhibition effect was not observed in infected cyanobacteria cells, which probably enables one to increase 2-7 times the concentration of amino acids in a cell. Such an increase of the amino acids pool is apparently necessary for realization of viral genome strategy.

Aspartate Kinase↗