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D N Ostrovskiĭ

Publications and source records attributed to D N Ostrovskiĭ.

64 records · Page 4Linked to original sources

[Growth of Micrococcus lysodeikticus bacteria on a deuterated medium].

The object of this work was to prepare deuterated growth media and to adapt Micrococcus lysodeikticus to a medium containing deuterated-substituted organic substances and deuterium oxide instead of water. M. lysodeikticus was grown on a medium prepared from the "deuterated-cells" of Chlorella, and was capable of absorbing selectively protons from such a medium containing high concentrations of deuterium. Its deuterated cells ("monsters") produced structures consisting of several (up to 8) smaller cells, angular in shape and having a thicker (2--3 times) cell wall. Apparently, adaptation to a deuterated medium is accompanied with changes in the cell wall biosynthesis as a result of which the separation of daughter cells is interfered with in the course of cell division, and the cells are more resistant to the action of lysozyme.

Adaptation, Physiological↗

[Study of nucleotide biosynthesis by cultured Brevibacterium ammoniagenes using P31 nuclear magnetic resonance spectroscopy].

Using P31 nuclear magnetic resonance, transformations of phosphorous compounds by the culture Brevibacterium ammoniagenes ATCC 6872 in the course of fermentation aimed at the synthesis of nicotinamide adenine dinucleotide were investigated. It was found that the NAD synthesis by the cells treated with surface active substances was markedly influenced by the presence of a small (initial) ATP quantity and was unaffected by an addition of the synthetic polyphosphate (n-40). It was demonstrated that the cells which were not treated with surface active substances contained orthophosphate, carbohydrate monophosphates, and minor quantities of nucleoside triphosphates, polyphosphates, mono- and dinucleotides. After treatment with surface active substances the cells lost these compounds. It is suggested that polyphosphates of the cell and adenosine monophosphate synthesized during its autolysis may enhance the recovery of the ATP level required to trigger glycolysis which serves as the major producer of ATP in the absence of oxidative phosphorylation.

Adenosine Triphosphate↗

[Deuterated membranes of Micrococcus lysodeikticus: production and several biochemical properties].

A technique has been elaborated for preparation of deuterated membranes from deuterated cells of Micrococcus lysodeikticus containing 85--90% of deuterium according to the data of IR and PMR spectroscopy. Normal lysis of the deuterated cells of M. lysodeikticus requires a concentration of lysozyme which is eight times higher than for usual cells (8 mg per 1 g of wet deuterated cells) and an addition of the lytic enzymes E-2 (2 mg per 1 g of wet deuterated cells). Preparations of deuterated membranes purified from ribosomes and proteins can be obtained by treating of the lysate with RNAase and washing in 0.5 M NaCl. The purity of the deuterated membranes was evaluated by the evidence of electron microscopy, IR spectra and enzyme activities. After hydrogen atoms were substituted by deuterium, the secondary structure of the total membrane protein, the ratio between the activities of the respiratory chain enzymes, and the relative content of the lipid and protein components of the deuterated membranes remain at the same level as in the protonated ones.

Catalysis↗

[Effect of antiseptics and redox-cycling agents on Corynebacterium ammoniagenes and related microorganisms in relation to synthesis of a new macroergic compound].

Sublethal concentration of the antiseptic composition Desoxon-1 was shown to provoke in cells of Corinebacterium ammoniagenes in a liquid medium the biosynthesis and accumulation of a novel macroergic 2-methylbutane-1,2,3,4-tetraol-2,4-cyclopyrophosphate. This substance is also synthesized when C. ammoniagenes is cultivated in a solid agar medium supplemented with benzylviologen. Cells preloaded with the new cyclopyrophosphate maintain its content when treated with 4% phenol, DP-2, Desoxon-1 or boiled and heated in an autoclave. Experiments with Mycobacterium tuberculosis and BCG revealed the ability of these bacteria to grow in a medium supplemented with BV++ possibly due to ability of synthesis of a new cyclopyrophosphate which was shown to correlate with resistance toward redox-cycling drugs. Accumulation of polyphosphates in the control cells of M. tuberculosis was illustrated by 31P-NMR spectroscopy and disappearance of the polyphosphates during cultivation in a BV(++)-supplemented medium. No signal of the new cyclopyrophosphate was yet registered in cells of M. tuberculosis by 31P-NMR.

Anti-Infective Agents, Local↗

[Relationship between the synthesis of a new stress response component and bacterial cell metabolism].

Various stress factors (incubation with redox-cycling agents, ozonization, heat shock) that induced accumulation of 2-C-methyl-D-erythritol-2,4-cyclopyrophosphate (MEC) were also shown to induce various alterations of the phospholipid composition in three microbial species: Corynebacterium ammoniagenes, Micrococcus luteus, and Staphylococcus aureus. The influence of adding 10 carbohydrates to the growth medium on MEC accumulation by C. ammoniagenes cells was tested. Only glucose and mannose exerted a pronounced stimulatory effect on the MEC synthesis under oxidative stress. The target of oxidative attack whose transformation causes MEC synthesis is suggested to be located near or on the bacterial cytoplasmic membrane.

Carbohydrates↗