Valentina E. Nikitina

Institute of Biochemistry and Physiology of Microorganisms, Pushchino-na-Oke, Moskovskaya, Russia

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Publications (25)23.67 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: The ability to reduce selenite (SeO3 (2-)) ions with the formation of selenium nanoparticles was demonstrated in Azospirillum brasilense for the first time. The influence of selenite ions on the growth of A. brasilense Sp7 and Sp245, two widely studied wild-type strains, was investigated. Growth of cultures on both liquid and solid (2 % agar) media in the presence of SeO3 (2-) was found to be accompanied by the appearance of the typical red colouration. By means of transmission electron microscopy (TEM), electron energy loss spectroscopy (EELS) and X-ray fluorescence analysis (XFA), intracellular accumulation of elementary selenium in the form of nanoparticles (50 to 400 nm in diameter) was demonstrated for both strains. The proposed mechanism of selenite-to-selenium (0) reduction could involve SeO3 (2-) in the denitrification process, which has been well studied in azospirilla, rather than a selenite detoxification strategy. The results obtained point to the possibility of using Azospirillum strains as endophytic or rhizospheric bacteria to assist phytoremediation of, and cereal cultivation on, selenium-contaminated soils. The ability of A. brasilense to synthesise selenium nanoparticles may be of interest to nanobiotechnology for "green synthesis" of bioavailable amorphous red selenium nanostructures.
    Microbial Ecology 05/2014; · 3.28 Impact Factor
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    ABSTRACT: We report for the first time that the medicinal basidiomycete Lentinus edodes can reduce Au(III) from chloroauric acid (HAuCl4) to elemental Au [Au(0)], forming nanoparticles. Several methods, including transmission electron microscopy, electron energy loss spectroscopy, X-ray fluorescence, and dynamic light scattering, were used to show that when the fungus was grown submerged, colloidal gold accumulated on the surface of and inside the mycelial hyphae as electron-dense particles mostly spherical in shape, with sizes ranging from 5 to 50nm. Homogeneous proteins (the fungal enzymes laccase, tyrosinase, and Mn-peroxidase) were found for the first time to be involved in the reduction of Au(III) to Au(0) from HAuCl4. A possible mechanism forming Au nanoparticles is discussed.
    Journal of Biotechnology 05/2014; · 3.18 Impact Factor
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    ABSTRACT: We report for the first time that the medicinal basidiomycete Lentinula edodes can reduce selenium from inorganic sodium selenite (Se(IV)) and the organoselenium compound 1,5-diphenyl-3-selenopentanedione-1,5 (DAPS-25) to the elemental state, forming spherical nanoparticles. Submerged cultivation of the fungus with sodium selenite or with DAPS-25 produced an intense red coloration of L. edodes mycelial hyphae, indicating accumulation of elemental selenium (Se(0)) in a red modification. Several methods, including transmission electron microscopy (TEM), electron energy loss spectroscopy (EELS), and X-ray fluorescence, were used to show that red Se(0) accumulated intracellularly in the fungal hyphae as electron-dense nanoparticles with a diameter of 180.51±16.82 nm. Under designated cultivation conditions, shiitake did not reduce selenium from sodium selenate (Se(VI)).
    The Journal of Microbiology 12/2013; 51(6):829-35. · 1.28 Impact Factor
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    ABSTRACT: under the Creative Commons Attribution 3.0 license, which allows users to download, copy and build upon published articles even for commercial purposes, as long as the author and publisher are properly credited, which ensures maximum dissemination and a wider impact of our publications. After this work has been published by InTech, authors have the right to republish it, in whole or part, in any publication of which they are the author, and to make other personal use of the work. Any republication, referencing or personal use of the work must explicitly identify the original source.
    01/2013;
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    ABSTRACT: We report for the first time that edible medicinal xylotrophic basidiomycetes belonging to various systematic groups, such as Lentinus edodes, Pleurotus ostreatus, Ganoderma lucidum, Grifola frondosa can reduce Au(III) from chloroauric acid (HAuCl4) to elementary Au [Au(0)], forming nanoparticles. Several methods, including transmission electron microscopy (TEM) and dynamic light scattering, were used in order to show that when the fungus was grown submerged, colloidal gold accumulated on the surface of and within the mycelial hyphae as electron-dense particles mostly spherical in shape with sizes ranging from 5 to 50 nm. The fungal phenol-oxidizing enzymes (laccases and tyrosinases) were found to be involved in the reduction of Au(III) to Au(0) from HAuCl4.
    Journal of Valeology. 01/2013; 4:51-56.
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    ABSTRACT: The present paper reports for the first time the transformation of an organic selenium compound into red selenium (Se), which causes the intense red pigmentation of Lentinula edodes (shiitake mushroom) mycelia. The biotransformation of 1,5-diphenyl-3-selenopentanedione-1,5 (diacetophenonyl selenide, preparation DAPS-25) was studied in liquid- and solid-phase cultures of L. edodes. In liquid culture medium, a red color develops in the mycelium at initial DAPS-25 concentrations equal to or higher than 0.1 mmol/l. The intensity and initiation time of coloration is Se concentration-dependent. Semiquantitative data obtained by physicochemical methods on the extent of Se and acetophenone production suggest that L. edodes is able to absorb and/or destruct this organic Se xenobiotic.
    Biological trace element research 04/2012; 149(1):97-101. · 1.92 Impact Factor
  • S.A. Alen’kina, V.E. Nikitina
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    ABSTRACT: The lectin of Azospirillum brasilense Sp7 at 40 μg ml-1 elicited two peaks of induction of nitric oxide synthesis in the roots of wheat seedlings after 3 and 26 h of coincubation. The lectin of A. brasilense Sp7.2.3, a mutant defective in lectin activity, produced the same effect, but the activation of nitric oxide synthesis in the roots was less in the case of 26-h incubation. Exposure to the lectins for 3 h increased citrulline synthesis in the plant cell to the same extent. This finding indicated that the Azospirillum lectins activate nitric oxide production through the NO signal system of plants, thereby acting as inducers of adaptation processes in the roots of wheat seedlings.
    Russian Agricultural Sciences 01/2010;
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    Olga M. Tsivileva, Alexei N. Pankratov, Valentina E. Nikitina
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    ABSTRACT: Along with a brief review of Lentinula edodes (shiitake mushroom) submerged cultivation history within the framework of important extracellular proteins biosynthesis, this study contains the authors’ own results. The possibility of regulating the lectin activity of shiitake using the synthetic components is shown. The time course of lectin production in culture liquid of L. edodes in different media under submerged culture conditions was studied. The activity of agglutinins depended on the ratio between carbon and nitrogen sources and the pH of the culture medium. A relationship between the chemical composition of nutrient medium, the activity of extracellular lectins of L. edodes, and the formation of pigmented mycelial film in liquid culture has been found. The formulation of medium, on which the brown mycelial film appears in several days of submerged cultivation, is proposed. The results obtained make a contribution to the present notion of biochemical processes that give rise to the occurrence of the aforesaid morphological structure of shiitake. Finally, two extracellular lectins from the submerged culture of L. edodes have been isolated and purified to homogeneity. Their physicochemical properties and composition have been studied. KeywordsExtracellular proteins-Lectins of higher fungi-Brown mycelial film-Molecular structure-Quantum chemical study
    Mycological Progress 01/2010; 9(2):157-167. · 1.61 Impact Factor
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    ABSTRACT: The complex of immunochemical methods was applied to study the ability of the lectin from the fungus Grifola frondosa (Fr.) S.F. Gray to interact with homologous and non-homologous rabbit and human polyclonal antibodies. The results of immunodot assay with the fragments of proteolytically cleaved antibodies demonstrated the binding of the lectin only with the Fab fragments (antigen-binding center) of homologous antibodies, which is evidence of specific “antigen-antibody” interaction. The revealed interaction of the lectin with non-homologous antibodies (rabbit antibodies to bacterial O-antigens and the commercial preparation of human g-globulin) is most likely accomplished due to the contact of the carbohydrate-binding region of the lectin with the carbohydrate moiety of the antibodies (“lectin-carbohydrate”). Immunofluorescence microscopy with homologous antibodies revealed that lectin was diffusely and unevenly distributed over the surface of the hyphae, forming agglomerates in the region of buckles and young shoots.
    Microbiology 01/2009; 78(2):202-207. · 0.65 Impact Factor
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    S.A. Alen’kina, V.E. Nikitina
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    ABSTRACT: It was found that two cell-surface lectins isolated from the nitrogen-fixing soil bacterium Azospirillum brasilense Sp7 and from its mutant defective in lectin activity, A. brasilense Sp7.2.3 can stimulate rapid formation of hydrogen peroxide, associated with an increase in the activities of oxalate oxidase and peroxidase in the roots of wheat seedlings. The most advantageous and most rapidly induced pathway of hydrogen peroxide formation was the oxidation of oxalic acid by oxalate oxidase because in this case, a 10-min treatment of the roots with the lectins at 10 µg ml-1 was sufficient. The data from this study attest that the Azospirillum lectins can act as inducers of adaptation processes in the roots of wheat seedlings.
    Journal of stress physiology & biochemistry. 01/2009;
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    ABSTRACT: The white-rot fungus Lentinus edodes produced D-melibiose-specific lectins and two laccase forms in a lignin-containing medium. The maxima of laccase and lectin activities coincided, falling within the period of active mycelial growth. The enzymes and lectins were isolated and purified by gel filtration followed by anion-exchange chromatography. The L. edodes lectins were found to be able to stabilize the activity of the fungus's own laccases. Lectin activity during the formation of lectin-enzyme complexes remained unchanged.
    Current Microbiology 11/2008; 57(4):381-5. · 1.52 Impact Factor
  • International Journal of Medicinal Mushrooms 01/2008; 10(1):65-72. · 0.84 Impact Factor
  • Valentina E. Nikitina, tsivileva@ibppm.sgu.ru, Alexei N. Pankratov, Nikolai A. Bychkov
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    ABSTRACT: Lentinula edodes was the first medicinal macrofungus to enter the realm of modern biotechnology. The present paper briefly reviews the history of the modern biotechnology of this mushroom starting with the production of the polysaccharide preparation lentinan, and ending with an overview of our own work regarding the production of lectins. Our work with lectins has involved studies of the effect of initial pH, carbon and nitrogen sources and the C:N ratio on lectin production in both the mycelium and culture medium. We have shown that lectin activity is related to morphological development, with the activity being highest in extracts of the pigmented mycelial films that precede fruiting body production.
    Food Technology and Biotechnology (imacan@pbf.hr); Vol.45 No.3. 01/2007;
  • L. V. Stepanova, V. E. Nikitina, A. S. Boiko
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    ABSTRACT: From the surface of the dikaryotic mycelium of the xylotrophic basidiomycete Grifola frondosa 0917 a lectin has been isolated with a molecular mass of 68 ± 1 kDa, consisting of two subunits of 33–34 kDa each. The lectin is a hydrophilic glycoprotein with the protein: glycan ratio of 3: 1. It exhibits high affinity to native rabbit erythrocytes and to human erythrocytes of the 0 blood group, but not to trypsin-treated ones. The hemagglutination (HA) caused by lectin was not blocked by any of the 25 tested mono-, di-, and amino sugars; it was also not blocked by some of glyco derivatives. Only 13.9 µg/ml of the homogeneous preparation of a polysaccharide, a linear D-rhamnan with the structure of the repeated component →2)-β-D-Rhap-(1→3)-α-D-Rhap-(1→3)-α-D-Rhap-(1→2)-α-D-Rhap-(1→2)-α-sD-Rhap-1(→ blocked hemagglutination completely. The analysis of the amino acid composition of the lectin showed the greatest percentage of amino acids with positively charged R groups, arginine, lysine, and histidine, as well as the complete absence of sulfurcontaining amino acids, cysteine, and methionine. D-glucose and D-glucosamine were detected in the carbohydrate part.
    Microbiology 01/2007; 76(4):429-434. · 0.65 Impact Factor
  • L V Stepanova, V E Nikitina, A S Boĭko
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    ABSTRACT: For the first time, from the surface of the dikaryotic mycelium of the xylotrophic basidiomycete Grifola frondosa 0917 a lectin has been isolated with a molecular mass of 68 +/- 1 kDa, consisting of two subunits of 33-34 kDa each. The lectin is a hydrophilic glycoprotein with the protein : glycan ratio of 3 : 1. It exhibits high affinity to native rabbit erythrocytes and to human erythrocytes of the 0 blood group, but not to trypsin-treated ones. The hemagglutination (HA) caused by lectin was not blocked by any of the 25 tested mono-, di-, and amino sugars; it was also not blocked by some of glyco derivatives. Only 13.9 microg/ml of the homogeneous preparation of a polysaccharide, a linear D-rhamnan with the structure of the repetitive component --> 2)-beta-D-Rhap-(1 --> 3)-alpha-D-Rhap-(1 --> 3)-alpha-D-Rhap-(1 --> 2)-alpha-D-Rhap-(1 --> 2)-alpha-D-Rhap-(1 --> blocked hemagglutination completely. The analysis of the amino acid composition of the lectin showed the greatest percentage of amino acids with positively charged R groups, arginine, lysine, and histidine, as well as the complete absence of sulfur-containing amino acids, cysteine, and methionine. D-glucose and D-glucosamine were detected in the carbohydrate part.
    Mikrobiologiia 01/2007; 76(4):488-93.
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    ABSTRACT: This work studied the effect of two cell-surface lectins isolated from the nitrogen-fixing soil bacterium Azospirillum brasilense Sp7 and from its mutant defective in hemagglutinating activity, A. brasilense Sp7.2.3, on the activities of α-glucosidase, β-glucosidase and β-galactosidase in the exocomponent, membrane and apoplast fractions of wheat-seedling roots. Lectin (40μgmL−1) incubation for 1h of the plant fractions increased the enzymes’ activities; both wild-type and mutant lectins were most stimulatory to the activities of all the exocomponent-fraction enzymes studied and to the apoplast-fraction β-glucosidase. Pretreatment of the lectins with their carbohydrate hapten, L-fucose, lowered the effect. The observed differences in the lectins’ ability to influence enzyme catalytic activity are explained by change in the antigenic properties of the mutant lectin.
    Plant and Soil 04/2006; 283(1):147-151. · 3.24 Impact Factor
  • Alexei N. Pankratov, Olga M. Tsivileva, Valentina E. Nikitina
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    ABSTRACT: Purpose – The purpose of this paper is to summarize the information about web resources in the area of mycology, one of the most important spheres of biology. Design/methodology/approach – The information on mycological web resources is systematised. Scientific journals, newsletters and magazines of mycological scope, along with their publishers, are presented. Findings – It is of use to biologists, chemists and other scientists and teachers working in the area of mycology, as well as scientists, who profess to disseminate scientific knowledge, to avail themselves of the myriad information sources on offer. Originality/value – This is possibly the first attempt to embrace comprehensively and in minute detail the vast field of information on the sources of contemporary mycology and its representative bodies.
    Online Information Review 01/2006; 30:43-52. · 0.94 Impact Factor
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    ABSTRACT: A relationship between the chemical composition of nutrient medium, the activity of extracellular lectins of Lentinus edodes (Berk.) Sing [Lentinula edodes (Berk.) Pegler] (shiita-ke), and the formation of pigmented mycelial film in liquid culture has been found. A pos-sibility to regulate the lectin activity of shiitake using the synthetic components has been shown. The formulation of medium, on which the brown mycelial film appears in several days of submerged cultivation, has been proposed. Among the natural amino acids stu-died as nitrogen sources, and nine divalent metal cations as inorganic additives, L-aspara-gine and Ca 2+ (Mn 2+) in the simultaneous presence exhibited the explicit positive effect in respect to the above without regard to the age of the culture. Quantum chemical methods and QSAR were applied to test our supposition that a differential character of interaction between the studied amino acids and Ca 2+ (Mn 2+) cations should be related not to the di-stinct electron structures of zwitter ions, but most likely to their differing hydrophobici-ties. The results obtained seem to make some contribution to the present notion of bioche-mical processes that give rise to the occurrence of the aforesaid morphological structure of shiitake.
    01/2005;
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    ABSTRACT: 47.0 ± 1.2 74 ± 2.5 42.7 ± 2.7 20.0 ± 1.2 20.0 ± 0.5 16.0 ± 1.6 F m + (L + F) 19.3 ± 1.0 21.0 ± 0.3 30.0 ± 1.2 17.5 ± 0.4 19.5 ± 0.8 12.2 ± 0.4 F m + (L + G) 18.0 ± 0.2 21.0 ± 2.1 25.0 ± 1.4 19.0 ± 1.7 20.0 ± 1.6 11.9 ± 2.5 F a 29.2 ± 1.7 2.0 ± 0.2 4.0 ± 0.2 29.2 ± 1.7 2.0 ± 0.2 4.0 ± 0.2 F a + L 60.4 ± 0.9 31.9 ± 1.1 24.0 ± 1.8 39.8 ± 0.7 19.0 ± 1.4 13.0 ± 1.2 F a + (L + F) 32.0 ± 1.2 12.0 ± 0.5 6.0 ± 0.4 28.3 ± 1.2 16.5 ± 1.4 12.5 ± 0.5 F a + (L + G) 29.3 ± 0.8 10.0 ± 0.4 4.9 ± 0.2 29.0 ± 0.5 17.0 ± 0.5 12.0 ± 0.5 Note: F e , fraction of root exometabolites; F m , fraction of root membranes; F a , fraction of root apoplasts; F + L, fraction incubated with lectin; F + (L + F), fraction incubated with lectin preincubated with L-fucose; F + (L + G), fraction incubated with lectin preincubated with D-galactose.
    Microbiology 01/2004; 73(6):732-733. · 0.65 Impact Factor
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    Alexei N. Pankratov, Olga M. Tsivileva, Valentina E. Nikitina
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    ABSTRACT: Based on the study by Leatham and Stabmann concerned with the rates (v) of amines and phenolic compounds oxidation catalyzed by laccase of basidiomycete Lentinus edodes (Berk.) Sing., as well as on the results of semiempirical quantum chemical computations using the PM3 method, the linear correlations of v and lnv values with first vertical ionization potentials of the substrates molecules and radicals derived from them, spin densities on N and O atoms of the above radicals, and with the radicals reorganization energies have been found.
    BMB reports 01/2000; 33(1). · 1.63 Impact Factor