[New aspects of the pleiotropic action of the genes coding Saccharomyces cerevisiae exopolyphosphatases].

Inactivation of the key genes, which are responsible for the enzymes of polyphosphates degradation, exopolyphosphatases ppx1 and ppn1, caused both an increase of polyphosphates content in Saccharomyces cerevisiae cells and an increase in chain length of acid-soluble and alkali-soluble fractions. It had no effect on the frequency of volutine granules metachromasy that was based on the interaction of dye molecules with ionic groups of polyphosphates. At the same time, a mutant strain reaction to nystatin differed from the reaction of the parental and wild-type strains when the metachromasy was absent.

[Effects of cellobiose lipid B on Saccharomyces cerevisiae cells: K+ leakage and inhibition of polyphosphate accumulation].

Cellobiose lipid B, a natural fungicide produced by the yeast Pseudozyma fusiformata, induces the leakage of K+ and ATP from cells of Saccharomyces cerevisiae. The presence of glucose decreases the effective concentration of cellobiose lipid B. The concentration of cellobiose lipid B was selected that results in a high rate of K+ leakage and a five- to sevenfold decrease in the intracellular ATP content, while the accumulation of acid-soluble polyphosphates decreased only by half.

[Antifungal cellobiose lipid secreted by the epiphytic yeast Pseudozyma graminicola].

The yeast Pseudozyma graminicola isolated from plants inhibited growth of almost all ascomycetes and basidiomycetes tested (over 270 species of ca. 100 genera) including pathogenic species. This yeast secreted a fungicidal agent, which was identified as a glycolipid composed of cellobiose residue with two O-substituents (acetyl and 3-hydroxycaproic acid) and 2,15,16-trihydroxypalmitic acid.

[Decrease of phosphate concentration in the medium by Brevibacterium casei cells].

Brevibacteria able to decrease phosphate concentration in the medium are of interest for the study of the role of bacteria in the phosphorus cycle and for development of biotechnology of phosphate removal from waste. Brevibacterium casei, Brevibacterium linens, and Brevibacterium epidermidis grown in media with initial phosphorus concentrations of 1-11 mM were shown to decrease its concentration by 90%. The composition of the incubation medium required for B.

[Fungicidal activity of cellobiose lipids from cultural fluid of yeast Cryptococcus humicola and Pseudozyma fusiformata].

Cellobiose lipids of yeast fungi Cryptococcus humicola and Pseudozyma fusiformata have similar fungicidal activities against different yeast, including pathogenic Cryptococcus and Candida species. Basidiomycetic yeast reveals maximum sensitivity to these preparations; e.g.

[Inactivation of the ppn1 gene exerts different effects on the metabolism of inorganic polyphosphates in the cytosol and the vacuoles of the yeast Saccharomyces cerevisiae].

Inactivation of the PPN1 gene, encoding one of the enzymes involved in polyphosphate metabolism in the yeast Saccharomyces cerevisiae, was found to decrease exopolyphosphatase activity in the cytosol and vacuoles. This effect was more pronounced in the stationary growth phase than in the phase of active growth. The gene inactivation resulted in elimination of a approximately 440-kDa exopolyphosphatase in the vacuoles but did not influence a previously unknown vacuolar exopolyphosphatase with a molecular mass of >1000 kDa, which differed from the former enzyme in the requirement for bivalent cations and sensitivity to heparin.

[The effect of inactivation of the exo- and endopolyphosphatase genes PPX1 and PPN1 on the level of different polyphosphates in the yeast Saccharomyces cerevisiae].

The inactivation of the PPX1 and PPN1 genes, which encode the major enzymes of polyphosphate degradation (exopolyphosphatase and endopolyphosphatase, respectively), was found to exert different effects on the content of different polyphosphates in the yeast Saccharomyces cerevisiae. The content of relatively low-molecular-weight acid-soluble polyphosphates in mutant yeast strains is inversely proportional to the exopolyphosphatase activity of the cytosol. At the same time, the mutation of these genes exerts no effect on salt-soluble polyphosphates.

[Peculiarities of metabolism and functions of high-molecular inorganic polyphosphates in yeasts as representatives of lower eukaryotes].

The review presents the recent data demonstrating the important role high-molecular inorganic polyphosphates in regulatory processes in a yeast cell. It has been shown that polyphosphates are localized in different cell compartments, where they are metabolized by a special set of enzymes. The review presents the evidence in favor of the concept of multiple functions of these biopolymers in a cell, as well as the data on the pleiotropic effects of mutations in the genes encoding the enzymes of polyphosphate metabolism.

[The fungicidal activity of an extracellular glycolipid from Sympodiomycopsis paphiopedili sugiyama et al].

The yeast Sympodiomycopsis paphiopedili (Ustilaginomycetes) produces an extracellular glycolipid, which possesses the maximum antifungal activity at the pH of the medium equal to 4.0-4.5.

[Mechanisms of the alkaloid aurantioclavine excretion and uptake during Penicillium nalgiovense VKM F-229 growth].

The biphasic dynamics of the alkaloid aurantioclavine in the culture liquid of Penicillium nalgiovense VKM F-229 is shown to be due to the diauxic growth of the fungus on two carbon sources, succinate and mannitol. In the phase of active growth on succinate, the fungus synthesizes aurantioclavine and excretes it into the medium in an energy-independent manner, as a result of which the concentration of the alkaloid in the culture liquid rises. During the phase of metabolic adaptation to the other carbon source, mannitol, the concentration of aurantioclavine in the culture liquid falls, probably due to the energy-dependent uptake of the alkaloid by fungal cells.

[Magnesium orthophosphate, a new form of reserve phosphates in the halophilic archaeon Halobacterium salinarium].

The accumulation and utilization of reserve phosphates in the extremely halophilic archaeon Halobacterium salinarium were studied. The growth of H. salinarium was found to depend on the initial concentration of inorganic phosphate (Pi) in the culture medium and its content in the inoculum.

[Pseudozyma fusiformata BKM Y-2821--a producer of antifungal glycolipid].

The yeast Pseudozyma fusiformata (the order Ustilaginales) produces an extracellular low-molecular-weight protease-resistant thermostable fungicide, which was active against more than 80% of the 280 yeast and yeastlike species tested. The fungicide, extracted with methanol and purified by column and thin-layer chromatography, was found to consist of glucose and saturated fatty acids.

[Inorganic polyphosphates and phosphohydrolases from Halobacterium salinarium].

Halobacterium salinarium grown in a liquid medium consumed up to 75% of phosphates originally present in the growth medium and accumulated up to 100 mumol Pi/g wet biomass by the time it entered the growth retardation phase. The content of acid-soluble oligophosphates in the biomass was maximum at the early stage of active growth and drastically decreased when cells reached the growth-retardation phase. The total content of alkali-soluble and acid-insoluble polyphosphates changed very little throughout the cultivation period (five days).

[Purification and characteristics of Saccharomyces cerevisiae cytosol polyphosphatase].

The polyphosphatase with specific activity of 283 units/mg was purified 3450-fold to homogeneity with 3.8% yield from cytosol of Saccharomyces cerevisiae yeast. Polyphosphatase is monomeric 40 kD protein.

[Characteristics of polyphosphatase activity of isolated mitochondria from Saccharomyces cerevisiae].

Saccharomyces cerevisiae mitochondria have a polyphosphatase activity which is insensitive to a number of inhibitors of mitochondrial ATPase and pyrophosphatase (PPase). Heparin (20 micrograms/ml) and EDTA (0.5 mM) do not inhibit ATPase and PPase activities but completely suppressed mitochondrial polyphosphatase activity.

[Characteristics of Saccharomyces cerevisiae nuclear polyphosphatase activity].

Saccharomyces cerevisiae nuclei possess a polyphosphatase activity which is insensitive to a number of inhibitors of ATPase and pyrophosphatase (PPase) activities of the same organelle. Heparin, an effective inhibitor of the nuclear polyphosphatase activity, does not alter either the ATPase and PPase activity. The nuclear polyphosphatase activity is optimal at pH 7.

[Immunoenzyme analysis of polyphosphatases from various compartments of yeast cells].

Antibodies against purified polyphosphatase from the Saccharomyces cerevisiae cell envelope inhibited the activity of this enzyme and the polyphosphatase activity of the cytosol, being without any effect on vacuolar and nuclear polyphosphatase activities from the same yeast species cells. Using immunoblotting, it has been shown that it is the 40 kDa polypeptide that binds to these antibodies in preparations of cell envelope and cytosolic polyphosphatase. The molecular mass of these polyphosphatases determined by other methods was almost indentical.

[Detection of polyphosphatase activity in isolated Saccharomyces cerevisiae nuclei].

Intact nuclei have been isolated from cells of a diploid strain of Saccharomyces cerevisiae. The isolated nuclei were free from cytoplasmic, mitochondrial and vacuolar marker enzymes. The protein to DNA ratio (w/w) was 11.

[Organelle specificity of yeast cell polyphosphatases].

The properties of purified cell envelope polyphosphatase, polyphosphatase activities of vacuoles and cytosol fractions of the Saccharomyces cerevisiae yeast have been compared. The whole body of evidence presently available suggest that each of the compartments under study is equipped with its own polyphosphatase which differs from polyphosphatases of other organelles. It is proposed that the organelle specificity of yeast polyphosphatases may reflect the endosymbiotic origin of eucaryotic cells.

[Characteristics of polyphosphatase activity of Saccharomyces cerevisiae cytosol].

The cytosol fraction purified from cellular organelles was obtained from S. cerevisiae yeast cells. This cytosolic fraction contained a polyphosphatase activity comprising nearly 65% of such in the protoplast homogenate.