Anna Korchagina

Prof. Anna Korchagina

Institute for Problems of Chemical and Energetic Technologies, Biysk, Altayskiy Kray, Russia
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Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

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

Representative Publications

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21 October 2022 in Plants
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Yulia GismatulinaYulia Gismatulina
Yulia Gismatulina
Vera V. BudaevaVera V. Budaeva
Vera V. Budaeva
AKAleksey N. Kortusov
Aleksey N. Kortusov
EKEkaterina I. Kashcheyeva
Ekaterina I. Kashcheyeva
Evgenia GladyshevaEvgenia Gladysheva
Evgenia Gladysheva
GSGennady V. Sakovich
Gennady V. Sakovich
Lignocellulosic biomass is of great interest as an alternative energy resource because it offers a range of merits. Miscanthus × giganteus is a lignocellulosic feedstock of special interest, as it combines a high biomass productivity with a low environmental impact, including CO2 emission control. The chemical composition of lignocellulose determines the application potential for efficient industrial processing. Here, we compiled a sample collection of Miscanthus × giganteus that had been cultivated in different climate regions between 2019 and 2021. The chemical composition was quantified by the conventional wet methods. The findings were compared with each other and with the known data. Starting as soon as the first vegetation year, Miscanthus was shown to feature the following chemical composition: 43.2–55.5% cellulose content, 17.1–25.1% acid-insoluble lignin content, 17.9–22.9% pentosan content, 0.90–2.95% ash content, and 0.3–1.2% extractives. The habitat and the surrounding environment were discovered herein to affect the chemical composition of Miscanthus. The stem part of Miscanthus was found to be richer in cellulose than the leaf (48.4–54.9% vs. 47.2–48.9%, respectively), regardless of the planation age and habitat. The obtained findings broaden the investigative geography of the chemical composition of Miscanthus and corroborate the high value of Miscanthus for industrial conversion thereof into cellulosic products worldwide.

27 November 2019 in Nanomaterials
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Vera V. BudaevaVera V. Budaeva
Vera V. Budaeva
Yulia GismatulinaYulia Gismatulina
Yulia Gismatulina
Galina Fedorovna MironovaGalina Fedorovna Mironova
Galina Fedorovna Mironova
Ekaterina A. SkibaEkaterina A. Skiba
Ekaterina A. Skiba
Evgenia GladyshevaEvgenia Gladysheva
Evgenia Gladysheva
GSGennady V. Sakovich
Gennady V. Sakovich
Bacterial nanocellulose (BNC) whose biosynthesis fully conforms to green chemistry principles arouses much interest of specialists in technical chemistry and materials science because of its specific properties, such as nanostructure, purity, thermal stability, reactivity, high crystallinity, etc. The functionalization of the BNC surface remains a priority research area of polymers. The present study was aimed at scaled production of an enlarged BNC sample and at synthesizing cellulose nitrate (CN) therefrom. Cyclic biosynthesis of BNC was run in a semisynthetic glucose medium of 10−72 L in volume by using the Medusomyces gisevii Sa-12 symbiont. The most representative BNC sample weighing 6800 g and having an α-cellulose content of 99% and a polymerization degree of 4000 was nitrated. The nitration of freeze-dried BNC was performed with sulfuric-nitric mixed acid. BNC was examined by scanning electron microscopy (SEM) and infrared spectroscopy (IR), and CN was explored to a fuller extent by SEM, IR, thermogravimetric analysis/differential scanning analysis (TGA/DTA) and 13C nuclear magnetic resonance (NMR) spectroscopy. The three-cycle biosynthesis of BNC with an increasing volume of the nutrient medium from 10 to 72 L was successfully scaled up in nonsterile conditions to afford 9432 g of BNC gel-films. CNs with a nitrogen content of 10.96% and a viscosity of 916 cP were synthesized. It was found by the SEM technique that the CN preserved the 3D reticulate structure of initial BNC fibers a marginal thickening of the nanofibers themselves. Different analytical techniques reliably proved the resultant nitration product to be CN. When dissolved in acetone, the CN was found to form a clear high-viscosity organogel whose further studies will broaden application fields of the modified BNC.

9 March 2023 in Frontiers in Immunology
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AKAnna Korchagina
Anna Korchagina
SSSergey A. Shein
Sergey A. Shein
EKEkaterina Koroleva
Ekaterina Koroleva
Alexei V. TumanovAlexei V. Tumanov
Alexei V. Tumanov
Innate lymphoid cells (ILCs) are heterogeneous innate immune cells which participate in host defense, mucosal repair and immunopathology by producing effector cytokines similarly to their adaptive immune cell counterparts. The development of ILC1, 2, and 3 subsets is controlled by core transcription factors: T-bet, GATA3, and RORγt, respectively. ILCs can undergo plasticity and transdifferentiate to other ILC subsets in response to invading pathogens and changes in local tissue environment. Accumulating evidence suggests that the plasticity and the maintenance of ILC identity is controlled by a balance between these and additional transcription factors such as STATs, Batf, Ikaros, Runx3, c-Maf, Bcl11b, and Zbtb46, activated in response to lineage-guiding cytokines. However, how interplay between these transcription factors leads to ILC plasticity and the maintenance of ILC identity remains hypothetical. In this review, we discuss recent advances in understanding transcriptional regulation of ILCs in homeostatic and inflammatory conditions.

21 December 2023 in Polymers
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EKEkaterina I. Kashcheyeva
Ekaterina I. Kashcheyeva
AKAnna Korchagina
Anna Korchagina
Yulia GismatulinaYulia Gismatulina
Yulia Gismatulina
Evgenia GladyshevaEvgenia Gladysheva
Evgenia Gladysheva
Vera V. BudaevaVera V. Budaeva
Vera V. Budaeva
GSGennady V. Sakovich
Gennady V. Sakovich
This study is focused on exploring the feasibility of simultaneously producing the two products, cellulose nitrates (CNs) and bacterial cellulose (BC), from Miscanthus × giganteus. The starting cellulose for them was isolated by successive treatments of the feedstock with HNO3 and NaOH solutions. The cellulose was subjected to enzymatic hydrolysis for 2, 8, and 24 h. The cellulose samples after the hydrolysis were distinct in structure from the starting sample (degree of polymerization (DP) 1770, degree of crystallinity (DC) 64%) and between each other (DP 1510–1760, DC 72–75%). The nitration showed that these samples and the starting cellulose could successfully be nitrated to furnish acetone-soluble CNs. Extending the hydrolysis time from 2 h to 24 h led to an enhanced yield of CNs from 116 to 131%, with the nitrogen content and the viscosity of the CN samples increasing from 11.35 to 11.83% and from 94 to 119 mPa·s, respectively. The SEM analysis demonstrated that CNs retained the fiber shape. The IR spectroscopy confirmed that the synthesized material was specifically CNs, as evidenced by the characteristic frequencies of 1657–1659, 1277, 832–833, 747, and 688–690 cm−1. Nutrient media derived from the hydrolyzates obtained in 8 h and 24 h were of good quality for the synthesis of BC, with yields of 11.1% and 9.6%, respectively. The BC samples had a reticulate structure made of interlaced microfibrils with 65 and 81 nm widths and DPs of 2100 and 2300, respectively. It is for the first time that such an approach for the simultaneous production of CNs and BC has been employed.

3 December 2021 in Polymers
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Nadezhda A. ShavyrkinaNadezhda A. Shavyrkina
Nadezhda A. Shavyrkina
Ekaterina A. SkibaEkaterina A. Skiba
Ekaterina A. Skiba
Anastasiya KazantsevaAnastasiya Kazantseva
Anastasiya Kazantseva
Evgenia GladyshevaEvgenia Gladysheva
Evgenia Gladysheva
Vera V. BudaevaVera V. Budaeva
Vera V. Budaeva
GSGennady V. Sakovich
Gennady V. Sakovich
One of the ways to enhance the yield of bacterial cellulose (BC) is by using dynamic aeration and different-type bioreactors because the microbial producers are strict aerobes. But in this case, the BC quality tends to worsen. Here we have combined static culture with aeration in the biosynthesis of BC by symbiotic Medusomyces gisevii Sa-12 for the first time. A new aeration method by feeding the air onto the growth medium surface is proposed herein. The culture was performed in a Binder-400 climate chamber. The study found that the air feed at a rate of 6.3 L/min allows a 25% increase in the BC yield. Moreover, this aeration mode resulted in BC samples of stable quality. The thermogravimetric and X-ray structural characteristics were retained: the crystallinity index in reflection and transmission geometries were 89% and 92%, respectively, and the allomorph Iα content was 94%. Slight decreases in the degree of polymerization (by 12.0% compared to the control―no aeration) and elastic modulus (by 12.6%) are not critical. Thus, the simple aeration by feeding the air onto the culture medium surface has turned out to be an excellent alternative to dynamic aeration. Usually, when the cultivation conditions, including the aeration ones, are changed, characteristics of the resultant BC are altered either, due to the sensitivity of individual microbial strains. In our case, the stable parameters of BC samples under variable aeration conditions are explained by the concomitant factors: the new efficient aeration method and the highly adaptive microbial producer―symbiotic Medusomyces gisevii Sa-12.

18 September 2022 in Polymers
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Journal Article
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EKEkaterina I. Kashcheyeva
Ekaterina I. Kashcheyeva
Yulia GismatulinaYulia Gismatulina
Yulia Gismatulina
Galina Fedorovna MironovaGalina Fedorovna Mironova
Galina Fedorovna Mironova
Evgenia GladyshevaEvgenia Gladysheva
Evgenia Gladysheva
Vera V. BudaevaVera V. Budaeva
Vera V. Budaeva
AKAnna Korchagina
Anna Korchagina
The present paper is a fundamental study on the physicochemical properties and hydrolysis behavior of cellulose samples differing in origin: bacterial, synthetic, and vegetal. Bacterial cellulose was produced by Medusomyces gisevii Sa-12 in an enzymatic hydrolyzate derived from oat-hull pulp. Synthetic cellulose was obtained from an aqueous glucose solution by electropolymerization. Plant-based cellulose was isolated by treatment of Miscanthus sacchariflorus with dilute NaOH and HNO3 solutions. We explored different properties of cellulose samples, such as chemical composition, degree of polymerization (DP), degree of crystallinity (DC), porosity, and reported infrared spectroscopy and scanning electron microscopy results. The hydrolysis behavior was most notable dependent on the origin of cellulose. For the bacterial cellulose sample (2010 DP, 90% DC, 89.4% RS yield), the major property affecting the hydrolysis behavior was its unique nanoscale reticulate structure promoting fast penetration of cellulases into the substrate structure. The study on enzymatic hydrolysis showed that the hydrolysis behavior of synthetic and Miscanthus celluloses was most influenced by the substrate properties such as DP, DC and morphological structure. The yield of reducing sugars (RS) by hydrolysis of synthetic cellulose exhibiting a 3140 DP, 80% DC, and highly depolymerization-resistant fibers was 27%. In contrast, the hydrolysis of Miscanthus-derived cellulose with a 1030 DP, 68% DC, and enzyme-accessible fibers provided the highest RS yield of 90%. The other properties examined herein (absence/presence of non-cellulosic impurities, specific surface, pore volume) had no considerable effect on the bioconversion of the cellulosic substrates.