The process of dying of a culture of Str. diacetilactis under conditions of prolonged culturing is accompanied by substantial changes in the composition of the cell lipids. In the lipids of young cells the basic components are mono- and diglucosyldiglycerides, as well as phospholipids--two glucophospholipids, cardiolipin, and phosphatidylglycerin; triglycerides and sterols are present in negligible amounts. As the Str. diacetilactis culture develops and undergoes degradation, an increase is observed in the total amount of extractable lipids. In this case the fraction of phospholipids increases (chiefly on account of cardiolipin), while the fraction of neutral glucolipids decreases. It was shown that in cell homogenates there is a negligible peroxidation of lipids, which is intensified as the culture dies off. There is a parallel acceleration of the uptake of O2 by cell suspensions from cultures of different ages. The detected changes in the lipids are correlated with the morphological and physiological indices of the state of the culture.

Carbohydrates↗

PubMedDate not supplied

[Changes in the composition and content of pigments in blue-green algae in relation to the spectral composition of light and of the illumination degree].

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Eukaryota↗

PubMedDate not supplied

[Changes in the composition and pigment content of blue-green algae in the presence of additional carbon and nitrogen sources].

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Carbon↗

PubMedDate not supplied

[Degradation of Anacystis nidulans cells by the action of cyanophage AS-1].

The sequence of degradation of the photosynthetic apparatus of Anacystia nidulans after virus infection was studied using different methods. In the first stages of pathogenesis changes in the structure and functional activity of the photosynthetic apparatus were shown to be insignificant. At the stages of marked degradation the system of oxygen release and light collecting complex are destroyed gradually. The reaction center of photosystem I is the most resistant to degeneration.

Cyanobacteria↗

PubMedDate not supplied

[Regulation of the differentiation processes in an Anabaena cylindrica culture].

The maximal frequency of heterocysts in the culture of Anabaena cylindrica grown in a nitrogen-free medium was found after 6 days of growth (6%); the number of heterocysts decreased to 1.8% with aging. The quantity of heterocysts in the culture decreased (they could even disappear completely) in the presence of ammonium salts as the source of nitrogen. The index of the shape (the length-to-width ratio of cells, %) decreased under these conditions though it increased in the other variants of the experiment. The incidence of heterocysts in the culture of A. cylindrica increased under the conditions of incubation at low temperature (+4 degrees C) to 8%. The effect was most pronounced when 1% glucose was added to the medium; then, the distance between heterocysts was 5-7 cells. The percentage of heterocysts in filaments increased to 8.3% when vegetative cells were decomposed at elevated temperature (+30 degrees C) in the light. Under the same conditions in the dark, heterocysts degraded and their number decreased to 0.8%. Spore formation in the culture was stimulated by calcium excess and phosphorus deficiency in the medium.

Culture Media↗

PubMedDate not supplied

[Interaction of cyanobacteria cells with methyl viologen].

Oxygen absorption instead of its evolution is induced in cell suspensions of the cyanobacteria Anacystis nidulans and Anabaena variabilis in the presence of methylviologen, an autoxidable electron acceptor, and triphenyltetrazolium chloride which is irreversibly reduced in the cells. The process occurs without addition of exogenous donors and does not depend on DCMU. Dichlorophenolindophenol and ascorbate do not stimulate the absorption. The blue colour of reduced methylviologen was not observed even after argon had been bubbled through a cuvette with the reaction mixture. Cell decoloration and lysis were found upon long contact with methylviologen. Elevated concentrations of DCMU also caused oxygen absorption in the light. Apparently, it is possible to induce oxidation of endogenous donors in the cells of the above cyanobacteria in the presence of methyl-viologen.

Absorption↗

PubMedDate not supplied

[Possibility of detecting pyocyanine in Pseudomonas aeruginosa cells].

Pyocyanin can be detected in the cells of Pseudomonas aeruginosa using UV and IR spectroscopy of disturbed complete inner reflection (DCIR). Intact cells of the parent strain liberating the pigment into the cultural broth and mutant cells lacking the ability contain pyocyanin within the cells. Occasionally, pyocyanin can be detected in the outer layers of the cells, which is more typical of the parent strain. In the freshly isolated fractions of the parent strain cellular walls, pyocyanin seems to be pesent in the bound state that has changed significantly its structural organization. In due course, the hypothetical complex pyocyanin--cellular wall decomposes to yield an "oxidized" pigment similar to that liberated into the cultural broth. the cell wall of the mutant possesses the properties of "oxidized" pyocyanin immediately after isolation of the fraction. The pigment cannot be identified in the fractions of cytoplasmic membranes; pyocyanin is present in the "oxidized" state in the fractions of cytoplasm for the cells of both types. The paper discusses the role of the permeability of cytoplasmic membranes in the transport of pyocyanin from the cytoplasm into the cellular wall of the bacterium and then into the surrounding medium.

Cell Wall↗