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Biomedical subjects

V I Panasenko

Publications and source records attributed to V I Panasenko.

30 records · Page 2Linked to original sources
PubMedDate not supplied

[Azospirillum brasilense SP245 mutants in production of anthranilic and indolyl-3-acetic acids].

The mutants of Azospirillum brasilense Sp245 altered in the production of anthranilic (Ant) and indolyl-3-acetic (IAA) acids were selected after the chemical or transposon facilitated mutagenesis and divided into the following three classes: Ant+IAA+, Ant+IAA- and Ant-IAA-. A hypothesis on the existence of a pattern for tryptophan conversion to anthranilate that is different from the classic pattern, and on the connection of the indolyl-3-acetic synthesis with this process is suggested.

Azospirillum brasilense↗
PubMedDate not supplied

[Bacterial polysaccharides of polymyxan 88A. Basic characteristics and extent of possible uses].

A new high-viscous polysaccharide polymyxan from Bacillus polymyxa 88A is described. Polymyxan consists of an acid high-viscous polysaccharide (Mw 1-10 MD) and a neutral low-viscous polysaccharide (Mw 100-300 kD), which is a glucomannan containing equal amounts of monosaccharides and traces of uronic acids. The acid high-viscous polysaccharide consists of 36% glucose, 36% mannose, 7% galactose and 21% glucuronic acid. Data are presented on the application of polymyxan in baking industry and for preparation of drilling muds.

Bacillus↗
PubMedDate not supplied

[Colonization of wheat root hairs and roots by agrobacteria].

Formation of extracellular structures in pure culture and in interaction with wheat root surface was studied by scanning and transmission electron microscopy. The effect of various factors (growth temperature as well as pretreatment of agrobacteria with kalanchoe extract, acetosyringone, and centrifugation) on formation of extracellular structures was tested. The data on Agrobacterium tumefaciens (wild strain C58 and mutants LBA2525 (virB2::lacZ) and LBA288 (without Ti plasmid)) adhesion to wheat root surface and root hairs after pretreatment of agrobacteria with inducer of virulence genes (vir) acetosyringone were obtained. Formation of agrobacterial cell aggregates on wheat root hair tips was demonstrated. The proportion of root hairs with agrobacterial aggregates on the root hair tip insignificantly changed after pretreatment with acetosyringone but considerably increased after treatment of A. tumefaciens C58 and LBA2525 with kalanchoe leaf extract. The most active colonization of root hairs and formation of agrobacterial aggregates on hair root tips was observed at 22 degrees C. The capacity of agrobacteria for adhesion on monocotyledon surface could be changed by pretreatment of bacteria with various surface-active substances. Bacterial cells subjected to centrifugation had a decreased capacity for attachment to both wheat root surface and root hairs. The relationship between the capacity for adhesion and pile production in agrobacteria was considered.

Agrobacterium tumefaciens↗
PubMedDate not supplied

[Effect of Congo red on the motility of the bacterium Azospirillum brasilense].

In semiliquid laboratory media, the bacterium Azospirillum brasilense migrates with the formation of swarming rings. It is demonstrated that adsorption of the sulfonated azodye Congo Red confers on A. brasilense the ability to consistently spread in a semiliquid agar and form microcolonies. Spontaneous variants of A. brasilense with rapid swarming are described, as well as variants that swarm in the presence of Congo Red. It is assumed that at least two types of compounds are formed, which are (a) necessary for swarming and/or spreading with the formation of microcolonies and (b) capable of interacting with Congo Red.

Azospirillum brasilense↗
PubMedDate not supplied

[Does a powerful electromagnetic field in the decimetric range possess genetic activity in relation to microorganisms?].

It was shown that mutants can occur in various microorganisms after a short-term exposure to electromagnetic field of 40 to 100 W/cm3 at 2375 MHz. Induction of mutants usually increases as the temperature rises and cell death rate grows to reach a maximum at a minimum survival rate. Colonial-morphological and biochemical phenotype changes are noted. Both specific and individual radiosensitivity are observed (from a 100 per cent loss of the studied character to the complete absence of the effect). Changes occur more frequently in the parameters determined by plasmids. There is a possibility to select thermoresistant variants without changing the genotype.

Bacteria↗
PubMedDate not supplied

[Fluorescent probe study of staphylococcal cell wall charges].

The effect of pH and MgCl2 concentration on the fluorescence of 1-anilinonaphthalene-8-sulfonate (ANS), an anion probe, was studied in suspensions of Staphylococcus aureus. The maximum of ANS fluorescence shifted towards the short wavelength region of the spectrum and its intensity increased when the cells were incubated in the medium with low pH and high ionic strength. The results are discussed in terms of electrostatic interactions between the anions of the probe and the negative space charge of the cell wall.

Anilino Naphthalenesulfonates↗
PubMedDate not supplied

[Effect of plasmid composition on the chemotaxis reaction of Azospirillum brasilense Sp245 associated with gramineae].

Correlation between the loss of the 120 and/or 130 kb plasmids by the spontaneous Azospirillum brasilense mutant and appearance of the Che(-)-phenotype towards 9-mono- and disaccharides has been established. The plasmid rearrangement is concomitant with the appearance of a new 44 Kda protein among the membrane proteins of azospirilli. Chemotaxis to alanine, glutamic acid, and to organic acids is not impaired.

Acids↗