Vladimir V. Ignatov

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The dynamics of adsorption of the nitrogen-fixing soil bacteria Azospirillum brasilense 75 and 80 (isolated from soil samples collected in Saratov Oblast, southern Russia) and A. brasilense Sp245 to the roots of seedlings of common spring wheat was studied in relation to inoculum size, period of incubation with the roots and bacterial-growth phase. The(More)
This paper reviews the results obtained in studies of the extracellular polysaccharides, lipopolysaccharide-protein complexes, polysaccharide-lipid complexes, lipopolysaccharides, and O-specific polysaccharides from bacteria of the genus Azospirillum. On the basis of present knowledge, the possible roles of the extracellular polysaccharides and(More)
An O-specific polysaccharide was isolated from the lipopolysaccharide of a plant-growth-promoting bacterium Azospirillum brasilense Sp245 and studied by sugar analyses along with one- and two-dimensional 1H and 13C NMR spectroscopy, including NOESY. The polysaccharide was found to be a new rhamnan with a pentasaccharide repeating unit having the following(More)
Quantum chemical methods AM1 and PM3 and chromatographic methods were used to qualitatively characterize pathways of bacterial production of indole-3-acetic acid (IAA). The standard free energy changes (delta G(o)'sum) for the synthesis of tryptophan (Trp) from chorismic acid via anthranilic acid and indole were calculated, as were those for several(More)
The hemagglutinating activity of submerged mycelium and culture liquid for four strains of Lentinus edodes (Berk.) Sing [L. edodes (Berk.) Pegler] was studied in the search for lectins. The hemagglutinating activity of culture liquid was substantially higher, compared with mycelium. The carbohydrate-binding capacity of the agglutinins was established, and(More)
The results of flame (FAAS) or graphite furnace atomic absorption spectrometric (GFAAS) analyses are presented and discussed on the accumulation of essential metals (Mg, Ca, Mn and Fe contained in the cultivation medium) and traces of each one of the conventionally xenobiotic elements from the group V, Co, Ni, Cu, Zn or Pb, added to the medium in(More)
Alexander A. Kamnev , Lyudmila P. Antonyuk, Marinela Colina, Anatoly V. Chernyshev, and Vladimir V. Ignatov 1 Laboratory of Biochemistry, Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, 410015 Saratov, Russia 2 Division of Chemistry, School of Sciences and Mathematics, Shef®eld Hallam University, Shef®eld(More)
Indole acetic acid (IAA) production in Azospirillum brasilense strain Sp245 is controlled by a 85 MDa plasmid naturally present in this bacterium. In the presence of L-tryptophan, anthranilic acid production and almost no IAA production occurs in a derivative strain harbouring a Tn5-Mob insertion in the 85 MDa plasmid. Agrobacterium tumefaciens strain(More)
The involvement of the carbohydrate components of the Azospirillum brasilenseSp245 capsules in bacterial protection from the action of extreme factors was investigated. The survival of encapsulated and non-encapsulated azospirilla exposed to elevated (46–48°C) and below-freezing (–20 and –70°C) temperatures, extreme pH values (2 and 10), and to drying was(More)
Exopolysaccharides (EPS) synthesized by Paenibacillus polymyxa 1465 in the course of batch cultivation were proven to contain neutral and acidic fractions. EPS are heterogeneous polysaccharides, represented by a complex of macromolecules with molecular mass of 7 × 104 to 2 × 106 Da. The acidic component was shown to be predominant in EPS preparations(More)