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Krumova E, Benkova D, Stoyancheva G, Dishliyska V, Miteva-Staleva J, Kostadinova A, Ivanov K, El-Sayed K, Staneva G, Elshoky HA. Exploring the mechanism underlying the antifungal activity of chitosan-based ZnO, CuO, and SiO 2 nanocomposites as nanopesticides against Fusarium solani and Alternaria solani. Int J Biol Macromol 2024; 268:131702. [PMID: 38643917 DOI: 10.1016/j.ijbiomac.2024.131702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 04/13/2024] [Accepted: 04/18/2024] [Indexed: 04/23/2024]
Abstract
Chitosan-based nanocomposites (CS NCs) are gaining considerable attention as multifaceted antifungal agents. This study investigated the antifungal activity of NCs against two phytopathogenic strains: Fusarium solani (F. solani) and Alternaria solani (A. solani). Moreover, it sheds light on their underlying mechanisms of action. The NCs, CS-ZnO, CS-CuO, and CS-SiO2, were characterized using advanced methods. Dynamic and electrophoretic light scattering techniques revealed their size range (60-170 nm) and cationic nature, as indicated by the positive zeta potential values (from +16 to +22 mV). Transmission electron microscopy revealed the morphology of the NCs as agglomerates formed between the chitosan and oxide components. X-ray diffraction patterns confirmed crystalline structures with specific peaks indicating their constituents. Antifungal assessments using the agar diffusion technique demonstrated significant inhibitory effects of the NCs on both fungal strains (1.5 to 4-fold), surpassing the performance of the positive control, nystatin. Notably, the NCs exhibited superior antifungal potency, with CS-ZnO NCs being the most effective. A. solani was the most sensitive strain to the studied agents. Furthermore, the tested NCs induced oxidative stress in fungal cells, which elevated stress biomarker levels, such as superoxide dismutase (SOD) activity and protein carbonyl content (PCC), 2.5 and 6-fold for the most active CS-CuO in F. solani respectively. Additionally, they triggered membrane lipid peroxidation up to 3-fold higher compared to control, a process that potentially compromises membrane integrity. Laurdan fluorescence spectroscopy highlighted alterations in the molecular organization of fungal cell membranes induced by the NCs. CS-CuO NCs induced a membrane rigidifying effect, while CS-SiO2 and CS-ZnO could rigidify membranes in A. solani and fluidize them in F. solani. In summary, this study provides an in-depth understanding of the interactions of CS-based NCs with two fungal strains, showing their antifungal activity and offering insights into their mechanisms of action. These findings emphasize the potential of these NCs as effective and versatile antifungal agents.
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Affiliation(s)
- Ekaterina Krumova
- Institute of Microbiology, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria.
| | - Dayana Benkova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria
| | - Galina Stoyancheva
- Institute of Microbiology, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria
| | | | - Jeny Miteva-Staleva
- Institute of Microbiology, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria
| | - Aneliya Kostadinova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria.
| | - Kamen Ivanov
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria; Institute of Electronics, Bulgarian Academy of Sciences, 1784 Sofia, Bulgaria
| | - Kh El-Sayed
- Faculty of Engineering, Galala University, Attaka 51745, Suez, Egypt; Nanotechnology and Advanced Materials Central Lab, Agricultural Research Center, Giza 12619, Egypt; Regional Center for Food and Feed, Agricultural Research Center, Giza 12619, Egypt
| | - Galya Staneva
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria.
| | - Hisham A Elshoky
- Nanotechnology and Advanced Materials Central Lab, Agricultural Research Center, Giza 12619, Egypt; Regional Center for Food and Feed, Agricultural Research Center, Giza 12619, Egypt; Tumor Biology Research Program, Department of Research, Children's Cancer Hospital, Cairo 11441, Egypt.
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Abrashev R, Krumova E, Petrova P, Eneva R, Dishliyska V, Gocheva Y, Engibarov S, Miteva-Staleva J, Spasova B, Kolyovska V, Angelova M. Glucose Catabolite Repression Participates in the Regulation of Sialidase Biosynthesis by Antarctic Strain Penicillium griseofulvum P29. J Fungi (Basel) 2024; 10:241. [PMID: 38667912 PMCID: PMC11051313 DOI: 10.3390/jof10040241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 03/18/2024] [Accepted: 03/21/2024] [Indexed: 04/28/2024] Open
Abstract
Sialidases (neuraminidases) catalyze the removal of terminal sialic acid residues from glycoproteins. Novel enzymes from non-clinical isolates are of increasing interest regarding their application in the food and pharmaceutical industry. The present study aimed to evaluate the participation of carbon catabolite repression (CCR) in the regulation of cold-active sialidase biosynthesis by the psychrotolerant fungal strain Penicillium griseofulvum P29, isolated from Antarctica. The presence of glucose inhibited sialidase activity in growing and non-growing fungal mycelia in a dose- and time-dependent manner. The same response was demonstrated with maltose and sucrose. The replacement of glucose with glucose-6-phosphate also exerted CCR. The addition of cAMP resulted in the partial de-repression of sialidase synthesis. The CCR in the psychrotolerant strain P. griseofulvum P29 did not depend on temperature. Sialidase might be subject to glucose repression by both at 10 and 25 °C. The fluorescent assay using 4MU-Neu5Ac for enzyme activity determination under increasing glucose concentrations evidenced that CCR may have a regulatory role in sialidase production. The real-time RT-PCR experiments revealed that the sialidase gene was subject to glucose repression. To our knowledge, this is the first report that has studied the effect of CCR on cold-active sialidase, produced by an Antarctic strain.
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Affiliation(s)
- Radoslav Abrashev
- Department of Mycology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Academician G. Bonchev 26, 1113 Sofia, Bulgaria; (R.A.); (E.K.); (V.D.); (J.M.-S.); (B.S.)
| | - Ekaterina Krumova
- Department of Mycology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Academician G. Bonchev 26, 1113 Sofia, Bulgaria; (R.A.); (E.K.); (V.D.); (J.M.-S.); (B.S.)
| | - Penka Petrova
- Department of General Microbiology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Academician G. Bonchev 26, 1113 Sofia, Bulgaria; (P.P.); (R.E.); (Y.G.); (S.E.)
| | - Rumyana Eneva
- Department of General Microbiology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Academician G. Bonchev 26, 1113 Sofia, Bulgaria; (P.P.); (R.E.); (Y.G.); (S.E.)
| | - Vladislava Dishliyska
- Department of Mycology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Academician G. Bonchev 26, 1113 Sofia, Bulgaria; (R.A.); (E.K.); (V.D.); (J.M.-S.); (B.S.)
| | - Yana Gocheva
- Department of General Microbiology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Academician G. Bonchev 26, 1113 Sofia, Bulgaria; (P.P.); (R.E.); (Y.G.); (S.E.)
| | - Stefan Engibarov
- Department of General Microbiology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Academician G. Bonchev 26, 1113 Sofia, Bulgaria; (P.P.); (R.E.); (Y.G.); (S.E.)
| | - Jeny Miteva-Staleva
- Department of Mycology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Academician G. Bonchev 26, 1113 Sofia, Bulgaria; (R.A.); (E.K.); (V.D.); (J.M.-S.); (B.S.)
| | - Boryana Spasova
- Department of Mycology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Academician G. Bonchev 26, 1113 Sofia, Bulgaria; (R.A.); (E.K.); (V.D.); (J.M.-S.); (B.S.)
| | - Vera Kolyovska
- Institute of Experimental Morphology, Pathology and Anthropology with Museum, Bulgarian Academy of Sciences, Academician G. Bonchev 25, 1113 Sofia, Bulgaria;
| | - Maria Angelova
- Department of Mycology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Academician G. Bonchev 26, 1113 Sofia, Bulgaria; (R.A.); (E.K.); (V.D.); (J.M.-S.); (B.S.)
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Dolashki A, Abrashev R, Kaynarov D, Krumova E, Velkova L, Eneva R, Engibarov S, Gocheva Y, Miteva-Staleva J, Dishliyska V, Spasova B, Angelova M, Dolashka P. Structural and functional characterization of cold-active sialidase isolated from Antarctic fungus Penicillium griseofulvum P29. Biochem Biophys Rep 2024; 37:101610. [PMID: 38155944 PMCID: PMC10753047 DOI: 10.1016/j.bbrep.2023.101610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 12/05/2023] [Accepted: 12/08/2023] [Indexed: 12/30/2023] Open
Abstract
The fungal strain, Penicillium griseofulvum P29, isolated from a soil sample taken from Terra Nova Bay, Antarctica, was found to be a good producer of sialidase (P29). The present study was focused on the purification and structural characterization of the enzyme. P29 enzyme was purified using a Q-Sepharose column and fast performance liquid chromatography separation on a Mono Q column. The determined molecular mass of the purified enzyme of 40 kDa by SDS-PAGE and 39924.40 Da by matrix desorption/ionization mass spectrometry (MALDI-TOF/MS) analysis correlated well with the calculated mass (39903.75 kDa) from the amino acid sequence of the enzyme. P29 sialidase shows a temperature optimum of 37 °C and low-temperature stability, confirming its cold-active nature. The enzyme is more active towards α(2 → 3) sialyl linkages than those containing α(2 → 6) linkages. Based on the determined amino acid sequence and 3D structural modeling, a 3D model of P29 sialidase was presented, and the properties of the enzyme were explained. The conformational stability of the enzyme was followed by fluorescence spectroscopy, and the new enzyme was found to be conformationally stable in the neutral pH range of pH 6 to pH 9. In addition, the enzyme was more stable in an alkaline environment than in an acidic environment. The purified cold-active enzyme is the only sialidase produced and characterized from Antarctic fungi to date.
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Affiliation(s)
- Aleksandar Dolashki
- Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, Sofia, 1113, Acad. Georgy Bonchev str., bl. 9, Bulgaria
| | - Radoslav Abrashev
- The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Sofia, 1113, Acad. G. Bonchev str., bl. 26, Bulgaria
| | - Dimitar Kaynarov
- Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, Sofia, 1113, Acad. Georgy Bonchev str., bl. 9, Bulgaria
| | - Ekaterina Krumova
- The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Sofia, 1113, Acad. G. Bonchev str., bl. 26, Bulgaria
| | - Lyudmila Velkova
- Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, Sofia, 1113, Acad. Georgy Bonchev str., bl. 9, Bulgaria
| | - Rumyana Eneva
- The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Sofia, 1113, Acad. G. Bonchev str., bl. 26, Bulgaria
| | - Stefan Engibarov
- The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Sofia, 1113, Acad. G. Bonchev str., bl. 26, Bulgaria
| | - Yana Gocheva
- The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Sofia, 1113, Acad. G. Bonchev str., bl. 26, Bulgaria
| | - Jeny Miteva-Staleva
- The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Sofia, 1113, Acad. G. Bonchev str., bl. 26, Bulgaria
| | - Vladislava Dishliyska
- The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Sofia, 1113, Acad. G. Bonchev str., bl. 26, Bulgaria
| | - Boryana Spasova
- The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Sofia, 1113, Acad. G. Bonchev str., bl. 26, Bulgaria
| | - Maria Angelova
- The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Sofia, 1113, Acad. G. Bonchev str., bl. 26, Bulgaria
| | - Pavlina Dolashka
- Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, Sofia, 1113, Acad. Georgy Bonchev str., bl. 9, Bulgaria
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Dishliyska V, Stoyancheva G, Abrashev R, Miteva-Staleva J, Spasova B, Angelova M, Krumova E. Catalase from the Antarctic Fungus Aspergillus fumigatus I-9-Biosynthesis and Gene Characterization. Indian J Microbiol 2023; 63:541-548. [PMID: 38031622 PMCID: PMC10682308 DOI: 10.1007/s12088-023-01110-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 10/07/2023] [Indexed: 12/01/2023] Open
Abstract
Extremely cold habitats are a serious challenge for the existing there organisms. Inhabitants of these conditions are mostly microorganisms and lower mycetae. The mechanisms of microbial adaptation to extreme conditions are still unclear. Low temperatures cause significant physiological and biochemical changes in cells. Recently, there has been increasing interest in the relationship between low-temperature exposure and oxidative stress events, as well as the importance of antioxidant enzymes for survival in such conditions. The catalase is involved in the first line of the cells' antioxidant defense. Published information supports the concept of a key role for catalase in antioxidant defense against cold stress in a wide range of organisms isolated from the Antarctic. Data on representatives of microscopic fungi, however, are rarely found. There is scarce information on the characterization of catalase synthesized by adapted to cold stress organisms. Overall, this study aimed to observe the role of catalase in the survival strategy of filamentous fungi in extremely cold habitats and to identify the gene encoded catalase enzyme. Our results clearly showed that catalase is the main part of antioxidant enzyme defense in fungal cells against oxidative stress caused by low temperature exposure.
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Affiliation(s)
- Vladislava Dishliyska
- Departament of Mycology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Acad. G, Bonchev Str. Bl.26, 1113 Sofia, Bulgaria
| | - Galina Stoyancheva
- Departament of General Microbiology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Acad. G, Bonchev Str. Bl.26, 1113 Sofia, Bulgaria
| | - Radoslav Abrashev
- Departament of Mycology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Acad. G, Bonchev Str. Bl.26, 1113 Sofia, Bulgaria
| | - Jeny Miteva-Staleva
- Departament of Mycology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Acad. G, Bonchev Str. Bl.26, 1113 Sofia, Bulgaria
| | - Boriana Spasova
- Departament of Mycology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Acad. G, Bonchev Str. Bl.26, 1113 Sofia, Bulgaria
| | - Maria Angelova
- Departament of Mycology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Acad. G, Bonchev Str. Bl.26, 1113 Sofia, Bulgaria
| | - Ekaterina Krumova
- Departament of Mycology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Acad. G, Bonchev Str. Bl.26, 1113 Sofia, Bulgaria
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Stoyancheva G, Dishliyska V, Miteva‐Staleva J, Kostadinova N, Abrashev R, Angelova M, Krumova E. Sequencing and gene expression analysis of catalase genes in Antarctic fungal strain Penicillium griseofulvum P29. Polar Biol 2022. [DOI: 10.1007/s00300-021-03001-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Krumova E, Abrashev R, Dishliyska V, Stoyancheva G, Kostadinova N, Miteva-Staleva J, Spasova B, Angelova M. Cold-active catalase from the psychrotolerant fungus Penicillium griseofulvum. J Basic Microbiol 2021; 61:782-794. [PMID: 34309887 DOI: 10.1002/jobm.202100209] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 06/23/2021] [Accepted: 07/13/2021] [Indexed: 11/08/2022]
Abstract
Cold-active catalase (CAT) elicits great interest because of its vast prospective at the medical, commercial, and biotechnological levels. The study paper reports the production of cold-active CAT by the strain Penicillium griseofulvum P29 isolated from Antarctic soil. Improved enzyme production was achieved by optimization of medium and culture conditions. Maximum CAT was demonstrated under low glucose content (2%), 10% inoculum size, temperature 20°C, and dissolved oxygen concentration (DO) 40%. An effective laboratory technology based on changing the oxidative stress level through an increase of DO in the bioreactor was developed. The used strategy resulted in a 1.7- and 1.4-fold enhanced total enzyme activity and maximum enzyme productivity. The enzyme was purified and characterized. P. griseofulvum P29 CAT was most active at approximately 20°C and pH 6.0. Its thermostability was in the range between 5°C and 40°C.
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Affiliation(s)
- Ekaterina Krumova
- Department of Mycology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Radoslav Abrashev
- Department of Mycology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Vladislava Dishliyska
- Department of Mycology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Galina Stoyancheva
- Department of General Microbiology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Nedelina Kostadinova
- Department of Mycology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Jeny Miteva-Staleva
- Department of Mycology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Boryana Spasova
- Department of Mycology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Maria Angelova
- Department of Mycology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Sofia, Bulgaria
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Abrashev R, Krumova E, Petrova P, Eneva R, Kostadinova N, Miteva-Staleva J, Engibarov S, Stoyancheva G, Gocheva Y, Kolyovska V, Dishliyska V, Spassova B, Angelova M. Distribution of a novel enzyme of sialidase family among native filamentous fungi. Fungal Biol 2021; 125:412-425. [PMID: 33910682 DOI: 10.1016/j.funbio.2020.12.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 11/18/2020] [Accepted: 12/23/2020] [Indexed: 11/25/2022]
Abstract
Sialidases (neuraminidases, EC 3.2.1.18) are widely distributed in biological systems but there are only scarce data on its production by filamentous fungi. The aim of this study was to obtain information about sialidase distribution in filamentous fungi from non-clinical isolates, to determine availability of sialidase gene, and to select a perspective producer. A total of 113 fungal strains belonging to Ascomycota and Zygomycota compassing 21 genera and 51 species were screened. Among them, 77 strains (11 orders, 14 families and 16 genera) were able to synthesize sialidase. Present data showed a habitat-dependent variation of sialidase activity between species and within species, depending on location. Sialidase gene was identified in sialidase-positive and sialidase-negative strains. . Among three perspective strains, the best producer was chosen based on their sialidase production depending on type of cultivation, medium composition, and growth temperature. The selected P. griseofulvum Р29 was cultivated in 3L bioreactor at 20 °C on medium supplemented with 0.5% milk whey. The results demonstrated better growth and 2.3-fold higher maximum enzyme activity compared to the shaken flask cultures. Moreover, the early occurring maximum (48 h) is an important prerequisite for future up scaling of the process.
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Affiliation(s)
- Radoslav Abrashev
- The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Academician G. Bonchev 26, 1113, Sofia, Bulgaria
| | - Ekaterina Krumova
- The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Academician G. Bonchev 26, 1113, Sofia, Bulgaria
| | - Penka Petrova
- The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Academician G. Bonchev 26, 1113, Sofia, Bulgaria
| | - Rumyana Eneva
- The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Academician G. Bonchev 26, 1113, Sofia, Bulgaria
| | - Nedelina Kostadinova
- The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Academician G. Bonchev 26, 1113, Sofia, Bulgaria
| | - Jeni Miteva-Staleva
- The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Academician G. Bonchev 26, 1113, Sofia, Bulgaria
| | - Stephan Engibarov
- The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Academician G. Bonchev 26, 1113, Sofia, Bulgaria
| | - Galina Stoyancheva
- The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Academician G. Bonchev 26, 1113, Sofia, Bulgaria
| | - Yana Gocheva
- The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Academician G. Bonchev 26, 1113, Sofia, Bulgaria
| | - Vera Kolyovska
- Institute of Experimental Morphology, Pathology and Anthropology with Museum, Bulgarian Academy of Sciences, Academician G. Bonchev 25, 1113 Sofia, Bulgaria
| | - Vladislava Dishliyska
- The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Academician G. Bonchev 26, 1113, Sofia, Bulgaria
| | - Boryana Spassova
- The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Academician G. Bonchev 26, 1113, Sofia, Bulgaria
| | - Maria Angelova
- The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Academician G. Bonchev 26, 1113, Sofia, Bulgaria.
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