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V S Podgorskiĭ

Publications and source records attributed to V S Podgorskiĭ.

At least 19 recordsLinked to original sources

[The taxonomic position, ecological aspects and physiological-biochemical characteristics of microorganisms having industrial importance].

The paper presents fundamental results of the investigations obtained in the Department of Physiology of Industrial Microorganisms at the Institute of Microbiology and Virology of the National Academy of Sciences of Ukraine for the recent 15-20 years, as well as the Department developments directed to creation of biotechnological preparations, products and processes, most of which have been put into practice of the national economy and health protection. Data have been presented concerning the study of systematics, biology and ecology of nocardioform and coryneform bacteria, lactic acid bacteria and yeasts. When studying physiological-biochemical peculiarities and biological effect of the studied microorganisms, considerable attention has been paid to growth physiology of lactic acid bacteria, yeasts, lectin-forming bacteria, to processes of shaping of fungal mycelium under the conditions of batch cultivation as well as to microorganisms which take part in sewage treatment for heavy metals and oil products. The work also deals with the problems of creation and application in the economy of preparations intended for treatment and prophylaxis of gastro-intestinal diseases of cattle, poultry and swine, for siloing fodder, of new lactic acid preparations of functional direction, technological grounds of sewage treatment for oil products and six-valent toxic chrome.

Bacteria↗

[Use of PCR for the identification of representatives of Lactobacillus and Streptococcus].

REP- and ERIC-PCR genome analysis of lactic acid bacteria of genera Lactobacillus and Streptococcus have shown the presence of REP- and ERIC-repetitive sequences with high degree of homology. Amplification products which separation in agar gel results in formation of a specific fingerprint are obtained under REP- and ERIC-PCR. It is shown that REP- and ERIC-specific primers can be used for PCR identification of both enterobacteria and lactic acid bacteria isolated from different ecological niches.

DNA Fingerprinting↗

[Optimization of the process of culturing yeast in the presence of the dispersed mineral palygorskite].

A positive effect from introduction of the highly dispersed mineral palygorskite in the nutrient medium for aerobic batch cultivation of the yeast Saccharomyces cerevisiae, the Kyivsky strain, used in production of champagne has been established experimentally. An adequate mathematical model describing the process of growth has been constructed. Optimal cultivation conditions have been determined which provided for the achievement of such yeast cell concentration in the culture fluid as 116 mln/ml, palygorskite concentration in the nutrient medium being 0.37 g/l and sucrose 2.0 +/- 0.2%. The yeast obtained possess higher fermentation activity.

Culture Media↗

[Certain features of culturing Saccharomyces cerevisiae (Kiev strain) in a wine medium].

The growth of yeast Saccharomyces cerevisiae Kyivsky strain, used in production of champagne, has been studied as affected by a number of factors. The optimum values of saccharose concentration and partial pressure of oxygen dissolved in the medium under which the carbohydrate source use efficiency achieved 9 mln cells/mg of saccharose have been established. The strain growth on the nutrient medium with 2% of saccharose traditionally used in the champagne production has been investigated under the conditions of periodic cultivation. It has been shown that at the beginning of cultivation the low values of the economic coefficient were determined by the Crabtree effect. The saccharose concentration in the culture liquid being decreased to 1%, the carbohydrate utilization efficiency decreases considerably. A chemostatic method of the strain cultivation under growth limitation has been proposed to achieve high concentrations of yeast. Under periodical cultivation the saccharose concentration in the culture liquid would be supported at the level of 0.5-1.0% by its fractional introduction to the fermenter.

Culture Media↗

[Biological deacidification of wines using lactic-acid bacteria and yeasts].

Based on a study of 200 lactic-acid bacteria monocultures and 30 associating lactic bacteria and yeasts cultures, a stable association was created formed by Leuconostoc oenos, Pediococcus pentosaceus and Saccharomyces cerevisiae yeasts, intended for the biological deacidification of wine. Physiology of microorganisms and their effect on the wine chemical composition was studied. By means of selective association, high quality fine wines were produced from the high-acid wines.

Food Microbiology↗

[Search for lectin producers among some yeast species].

Hemagglutinating properties of culture liquid and cells of 142 yeast strains of species Saccharomyces cerevisiae, Kluyveromyces marxianus, K. dobzhanskii, K. lactis var. lactis and K. lactis var. drosophilarum, isolated from various sources have been studied. A capacity of yeast (44% of the studied strains) to synthesize both lectins bound to a cell and extracellular lectins has been established; the latter have been found in yeast for the first time.

Culture Media↗

[On the identity of Candida utilis and Pichia jadinii yeast species].

Life cycles of Candida utilis (Henneberg) Lodder et Kreger-van Rij imperfect yeast (13 strains) used in industry were the study subject. When the strains were mated, we detected one of the stages of sexual process--conjugation of cells of the opposite mating type. Most of the studied cultures conjugated on the 2d-3d day. No ascospores were formed. Haploidy and heterothallism of the studied C. utilis strains were confirmed by hybridization of auxotrophic mutants. Based on PCR assay results, the yeasts are demonstrated to belong to the ascospore perfect yeast species of Pichia jadinii (A. et R. Sartory. We ill et Meyer, Wickerham) Kurtzman.

Candida↗

[Search for lectin producers among the yeast of Pichia Hansen emend. Kurtzman genus].

Strains (103) of yeast from Pichia genus: P. anomala, P. guilliermondii and P. membranaefaciens species have been investigated. The researchers have found 87 strains (84.5%) capable to form extracellular and surface lectins with activity to 512 hemagglutinating units. The overwhelming number of strains (75.7-92.6%) synthesized lectins of the both forms. Considerably less quantity of lectin producers of some form--extracellular or surface ones--have been found. Availability of producers of extracellular lectins was characteristic to greater extent of the yeast of P. anomala and P. guilliermondii, and producers of surface lectins--mainly of P. guilliermondii. The most active producers of lectins have been isolated from human and animal organisms, soils and wine.

Hemagglutination Tests↗

[Probiotics based on live cultures of microorganisms].

The modern state of probiotic design and production was discussed in the survey. The worldwide data concerning types of probiotics and their use for restoration of resident microflora of hot-blooded animals and people were systematized. Much attention has been recently paid to the use of the natural preparations to maintain and regenerate the state of the resident microflora of animals and people. These preparations are known as probiotics. The term "probiotic" means microorganisms or substances which are capable to render sanitary effect on macroorganism. I. I. Mechnikov's concept on detoxifications of harmful substances formed in the digestive tract of men by probiotics is expounded. The modern concepts of the probiotics division into groups have been presented. Different kinds of industrial probiotics were considered. The mechanism of positive action of probiotics and their mutual relations with micro- and macroorganisms were provided. The scientific substantiation of new probiotic design was presented.

Animals↗

[Lectin activity of antitumor substances synthesized by Bacillus subtilis B-7025].

Nutrient medium, which is optimal for synthesis of biologically active substances and allows obtaining stable outflow of Bacillus subtilis B-7025 to the culture medium, has been selected under the conditions of the bacillus periodic cultivation. It has been established that these substances are extracellular lectins with high activity and carbohydrate specificity to fructose-1.6-di phosphate, N-acetylneuraminic acid and glucose derivatives: D-glucuronic acid and D-glucosamine.

Antineoplastic Agents↗

[Taxonomy, ecology, and physiological and biochemical characteristics of industrially important microorganisms].

The work is dedicated to the investigations which were carried out in the Department of Physiology of Industrial Microorganisms in the recent years. Fundamental results of investigations dedicated to development of systematics of nocardio- and coryne-like bacteria, lactic acid bacteria and yeast; to the study of their distribution in nature, physiological-and-biochemical peculiarities. Considerable attention is paid to growth physiology of lactic acid bacteria and yeast, to lectin-forming microorganisms, to the study of fungi shaping under deep cultivation, as well as to microorganisms, taking part in the environment purification from heavy metals and oil products. Drugs created for treatment and prophylaxis of cattle diseases, for fodder siloing; new lactic acid preparations of functional direction, technological bases of sewage treatment for oil products and heavy metals are described.

Academies and Institutes↗

[Yeasts--biosorbents of heavy metals].

The sharp increase of the level of environment pollution by heavy metals caused the increase of interest to the problem of live organisms (including microorganisms) resistance to these metals. Biosorption is one of the mechanisms of microorganisms resistance to heavy metals. Yeasts as biosorbents are of special interest. An analysis of the data from literature have shown that the yeast biomass may be used successfully as biosorption material for such metals as Ag, Au, Cd, Co, Cr, Cu, Ni, Pb, U, Th, Zn. Yeasts of genera Saccharomyces, Candida, Pichia are efficient biosorbents of metals. The sorptional system estimation is based on the classic sorption isotherm obtained in the course of equilibrium experiments and depends on pH, properties of metal ions, biomass concentration, preliminary physical or chemical treatment of the biomass, presence of various organic and inorganic ions and on temperature. The yeast biomass may be obtained using numerous industrial processes, that decreases considerably the biosorbent cost. Most yeasts can sorb a wide range of metals or be strictly specific in respect of only one metal. Special attention would be paid to the cell wall which structure determines sorption proceeding mechanisms. Problems of mechanisms of heavy metal biosorption by microorganisms at molecular level are discussed. The review also deals with the newest developments on improving the biosorption processes in microorganisms, yeast in particular.

Biodegradation, Environmental↗

[Search of heavy metals biosorbents among yeasts of different taxonomic groups].

The use of microbial cells as heavy metal biosorbents is a potential alternative for the existing methods of the environment treatment for pollution by these metals. Yeast may be successfully used in the metals sorption. An agar-plate screening method was used for rapid isolation of metal-accumulating strains of yeast and preliminary estimation of their biosorption capacity. The capacity to accumulate heavy metals, such as copper, zinc, lead, chrome and cobalt was estimated in 68 pigmented and pigmentless yeast strains isolated from different sources. The best capacity of copper and zinc accumulation was shown by pink-coloured Rhodotorula mucilaginosa, Rhodotorula aurantiaca, Rhodotorula glutinis and pigmentless strains of the yeast Candida krusei, Williopsis california.

Biodegradation, Environmental↗

[Effect of chromium (VI) on growth physiology and sorptional capacity of yeast].

Resistance of 7 yeast species (7 strains) to various chrome concentrations in the medium and their sorptional activity have been studied. It is shown that the biomass of the yeast Williopsis californica UKM-248, Candida krusei UKM-61t under their concentration in the medium of 200 and 500 mg/l of Cr6+ is 0.74 and 0.45 g/l DWB, respectively. For the rest of strains these chrome concentrations are toxical and the concentration of 100 mg/l of Cr6+ is the bordering threshold for them. Under periodical cultivation in the medium with 30 mg/l of Cr6+ one can observe the delay of cultures growth displayed in the increase of the lag-phase and exponential growth phase as well as the decrease of medium pH (to 2). The resistance of the studied yeast to high concentrations of Cr6+ correlates with their sorptional activity.

Biomass↗

[Effect of radio-frequency electromagnetic radiation on physiological features of Saccharomyces cerevisiae strain UCM Y-517].

Effect of electromagnetic radiation (40.68 MHz) on growth characteristics of Saccharomyces cerevisiae strain UCM Y-517 has been studied. Reliable increase of the specific growth rate (by 7-15%) and change of duration of growth phases as a result of irradiation of yeast population has been shown. The EMR effect has been found to depend on physiological state of the irradiated cells and composition of the irradiation performance medium: reliable effects were found only for the cells preliminarily grown on the dense nutrition medium in the late phase of delayed growth or on achieving the stationary growth phase. The role of radiation term and power as well as of temperature factor in EMR effect on the cells is discussed. It has been noted that the dependence of specific growth rate of yeast on the initial density of cells population acquire the nonlinear character as affected by EMR of radiofrequency range.

Cell Cycle↗

[Adhesion of lactic acid bacteria to epithelium of different cavities of the human organism].

During investigation of adhesive properties of lactic acid bacteria it was found out that 11 strains adhered to buccal intestinal and vaginal epithelium of human. The highest adhesive activity was detected in enterococci (adhesive index 7.75-14.26), lower one--in streptococci (6.40-9.16). In lactobacilli adhesive properties manifested in different ways: Lactobacillus acidophilus strains adhered more often to buccal epithelium (2.58-4.60) and rarely--to intestinal and vaginal. L. plantarum manifested high adhesive activity (8.03 -9.69) to buccal epithelium and lower one--to the rest of epithelium types. Monosaccharide composition of glycocalix of 6 strains of lactic acid bacteria was studied to understand the adhesion mechanism. It was shown that surface structures of this microorganism interact with plant lectins, specific to certain monosaccharides.

Bacterial Adhesion↗