Nikolay Stepanov

Dr. Nikolay Stepanov

orcid

Research Focus & Metrics

Academic Career Length

16Years (2011-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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26 February 2024 in Microorganisms
Verified
Journal Article
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EEElena Efremenko
Elena Efremenko
NSNikolay Stepanov
Nikolay Stepanov
OSOlga Senko
Olga Senko
AAAysel Aslanli
Aysel Aslanli
OMOlga Maslova
Olga Maslova
ILIlya Lyagin
Ilya Lyagin
There is currently growing interest in the creation of artificial microbial consortia, especially in the field of developing and applying various bioremediation processes. Heavy metals, dyes, synthetic polymers (microplastics), pesticides, polycyclic aromatic hydrocarbons and pharmaceutical agents are among the pollutants that have been mainly targeted by bioremediation based on various consortia containing fungi (mycelial types and yeasts). Such consortia can be designed both for the treatment of soil and water. This review is aimed at analyzing the recent achievements in the research of the artificial microbial consortia that are useful for environmental and bioremediation technologies, where various fungal cells are applied. The main tendencies in the formation of certain microbial combinations, and preferences in their forms for usage (suspended or immobilized), are evaluated using current publications, and the place of genetically modified cells in artificial consortia with fungi is assessed. The effect of multicomponence of the artificial consortia containing various fungal cells is estimated, as well as the influence of this factor on the functioning efficiency of the consortia and the pollutant removal efficacy. The conclusions of the review can be useful for the development of new mixed microbial biocatalysts and eco-compatible remediation processes that implement fungal cells.

14 September 2017 in Catalysts
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OMOlga Maslova
Olga Maslova
AAAysel Aslanli
Aysel Aslanli
NSNikolay Stepanov
Nikolay Stepanov
ILIlya Lyagin
Ilya Lyagin
EEElena Efremenko
Elena Efremenko
Catalytic characteristics of hexahistidine-containing organophosphorus hydrolase (His6-OPH) and its enzyme-polyelectrolyte complexes with poly-l-glutamic acid or poly-l-aspartic acid (His6-OPH/PLD50), hydrolyzing organophosphorous compounds, and N-acyl homoserine lactones were studied in the presence of various antibiotics (ampicillin, gentamicin, kanamycin, and rifampicin). The antibiotics at concentrations below 1 g·L−1 had a negligible inhibiting effect on the His6-OPH activity. Mixed inhibition of His6-OPH was established for higher antibiotic concentrations, and rifampicin was the most potent inhibitor. Stabilization of the His6-OPH activity was observed in the presence of antibiotics at a concentration of 0.2 g·L−1 during exposure at 25–41 °C. Molecular docking of antibiotics to the surface of His6-OPH dimer revealed the antibiotics binding both to the area near active centers of the enzyme subunits and to the region of contact between subunits of the dimer. Such interactions between antibiotics and His6-OPH were verified with Fourier-transform infrared (FTIR) spectroscopy. Considering all the results of the study, the combination of His6-OPH/PLD50 with β-lactam antibiotic ampicillin was established as the optimal one in terms of exhibition and persistence of maximal lactonase activity of the enzyme.

25 May 2023 in Microorganisms
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Journal Article
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EEElena Efremenko
Elena Efremenko
OSOlga Senko
Olga Senko
NSNikolay Stepanov
Nikolay Stepanov
AAAysel Aslanli
Aysel Aslanli
OMOlga Maslova
Olga Maslova
ILIlya Lyagin
Ilya Lyagin
Quorum sensing (QS) of various microorganisms (bacteria, fungi, microalgae) today attracts the attention of researchers mainly from the point of view of clarifying the biochemical basics of this general biological phenomenon, establishing chemical compounds that regulate it, and studying the mechanisms of its realization. Such information is primarily aimed at its use in solving environmental problems and the development of effective antimicrobial agents. This review is oriented on other aspects of the application of such knowledge; in particular, it discusses the role of QS in the elaboration of various prospective biocatalytic systems for different biotechnological processes carried out under aerobic and anaerobic conditions (synthesis of enzymes, polysaccharides, organic acids, etc.). Particular attention is paid to the biotechnological aspects of QS application and the use of biocatalysts, which have a heterogeneous microbial composition. The priorities of how to trigger a quorum response in immobilized cells to maintain their long-term productive and stable metabolic functioning are also discussed. There are several approaches that can be realized: increase in cell concentration, introduction of inductors for synthesis of QS-molecules, addition of QS-molecules, and provoking competition between the participants of heterogeneous biocatalysts, etc.).

18 January 2018 in Catalysts
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Journal Article
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NSNikolay Stepanov
Nikolay Stepanov
EEElena Efremenko
Elena Efremenko
A new biocatalyst in the form of Komagataeibacter xylinum B-12429 cells immobilized in poly(vinyl alcohol) cryogel for production of bacterial cellulose was demonstrated. Normally, the increased bacteria concentration causes an enlarged bacterial cellulose synthesis while cells push the polysaccharide out to pack themselves into this polymer and go into a stasis. Immobilization of cells into the poly(vinyl alcohol) cryogel allowed “deceiving” them: bacteria producing cellulose pushed it out, which further passed through the pores of cryogel matrix and was accumulated in the medium while not covering the cells; hence, the latter were deprived of a possible transition to inactivity and worked on the synthesis of bacterial cellulose even more actively. The repeated use of immobilized cells retaining 100% of their metabolic activity for at least 10 working cycles (60 days) was performed. The immobilized cells produce bacterial cellulose with crystallinity and porosity similar to polysaccharide of free cells, but having improved stiffness and tensile strength. Various media containing sugars and glycerol, based on hydrolysates of renewable biomass sources (aspen, Jerusalem artichoke, rice straw, microalgae) were successfully applied for bacterial cellulose production by immobilized cells, and the level of polysaccharide accumulation was 1.3–1.8-times greater than suspended cells could produce.

21 November 2022 in Chemosensors
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Journal Article
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EEElena Efremenko
Elena Efremenko
OSOlga Senko
Olga Senko
NSNikolay Stepanov
Nikolay Stepanov
OMOlga Maslova
Olga Maslova
GLGalina Yu. Lomakina
Galina Yu. Lomakina
NUNatalia Nicolaevna Ugarova
Natalia Nicolaevna Ugarova
Bioluminescent analysis of adenosine triphosphate (ATP) concentrations is now acquiring new applications in the form of objects and processes in which it can be effectively used for sensing. A quick analysis of biological objects and systems for which the level of ATP concentrations is one of the main parameters, and a forecast of the development of various situations in such biosystems under industrial production conditions or the ecological state of the environment, confirmed by various results of analytical control of other parameters, turns out to be simple and effective. Sanitary control, quality control of purified water, microbial analysis in the food industry, maintenance of drugs and estimation of their quality, and monitoring of the metabolic state of biocatalysts used in various biotechnological processes are between the main trends of recent applications of bioluminescent ATP-assay. Additionally, the new areas of ATP sensing are developed, and the following topics are their creation of synthetic microbial consortia, their introduction as new biocatalysts to biodegradation of pesticides, suppression of methane accumulation in model urban land fields, control of dangerous development of biocorrosive processes, design of chemical-biocatalytic hybrid processes, creation of effective antimicrobial dressing and protective tissue materials, etc. These aspects are the subject of this review.

Verified
Journal Article
Open access
PDF file
EEElena Efremenko
Elena Efremenko
NSNikolay Stepanov
Nikolay Stepanov
AAAysel Aslanli
Aysel Aslanli
ILIlya Lyagin
Ilya Lyagin
OSOlga Senko
Olga Senko
OMOlga Maslova
Olga Maslova
Multidrug-resistant bacteria form serious problems in many areas, including medicine and the food industry. At the same time, great interest is shown in the transfer or enhancement of antimicrobial properties to various materials by modifying them with enzymes. The use of enzymes in biomaterials with antimicrobial properties is important because enzymes can be used as the main active components providing antimicrobial properties of functionalized composite biomaterials, or can serve as enhancers of the antimicrobial action of certain substances (antibiotics, antimicrobial peptides, metal nanoparticles, etc.) against cells of various microorganisms. Enzymes can simultaneously widen the spectrum of antimicrobial activity of biomaterials. This review presents the most promising enzymes recently used for the production of antibacterial materials, namely hydrolases and oxidoreductases. Computer modeling plays an important role in finding the most effective combinations between enzymes and antimicrobial compounds, revealing their possible interactions. The range of materials that can be functionalized using enzymes looks diverse. The physicochemical characteristics and functionalization methods of the materials have a significant impact on the activity of enzymes. In this context, fibrous materials are of particular interest. The purpose of this review is to analyze the current state of the art in this area.