Section of MYCOLOGY
Head: Assoc. Professor Ekaterina Krumova, PhD
Tel: +359 2 979 31 26
Expert Consultancy : Prof. Maria Angelova, DSc
Теl: + 359-02-979-31-26, e-mail: email@example.com, firstname.lastname@example.org
Assist. Professor Radoslav Ignatov Abrashev, PhD
Теl: +359-02-979-31-28, e-mail: email@example.com
Assist. Professor Nedelina Stoyanova Kostadinova, PhD
Теl: +359-02-979-31-28, e-mail: firstname.lastname@example.org
Assist. Professor Svetlana Bojanova Pashova, MS
Теl: + 359-02-979-31-33, e-mail: email@example.com
Assist. Professor Vladislava Georgieva Dishliiska, MS
Теl: + 359-02-979-31-28,e-mail: firstname.lastname@example.org
Assist. Professor Jeni Georgieva Miteva-Staleva, MS
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Researchеr Borjana Kancheva Spasova, MS
Теl: + 359-02-979-31-28
Technican Emilia Evtova
Main Research Topics
· Taxonomic identification of fungal species;
· Fungal morphology, physiology and biochemistry under normophysiological and stress conditions;
· Fungal cell response against different type of stresses such as oxidative stress, heat- and cold shock, stress of immobilization and heavy metal exposure; evaluation of oxidative stress biomarkers; antioxidant enzyme defence;
· Fungal cell factories for production of valuable biological-active compounds by free and immobilized cultures; cold-active enzymes; regulatory mechanisms in the biosynthesis; purification and characterization of enzymes;
· Fungal biodegradation of natural and synthetic polymers (wood, leather, textile, historical records, etc.); laboratory expertise, consultations, instructions for preservation and elimination of fungi; mechanism of action of fungicide substances; methods for application of fungicides.
1. Fungal diversity
A sizeable fungal collection was developed along with the isolation of strains from temperate and extreme environments. There are species from the three major groups of true fungi: Basidiomycota, Ascomycota and Zygomycota. Most of them were identified by genus and species. According to the temperature range for growth, they were classified as extremely psychrophilic, psychrotrophic or mesophilic fungi. Antarctic strains were isolated from samples taken from different sources.
2. Oxidative stress (OS)
We focus our attention on better understanding OS response in lower multicellular eukaryotes. Filamentous fungi from different species are using as model microorganisms. Treatment of the fungal strains with various stimuli generating reactive oxygen species (ROS) induces a state of oxidative stress. Related research targets evaluation of: (1) stress biomarkers (cyanide-resistant respiration; direct assessment of ROS production; oxidative damaged proteins; synthesis of reserve carbohydrates etc); (2) antioxidant enzyme defence (superoxide dismutase, SOD and catalase, CAT); (3) subcellular localization of SOD isoenzymes; (4) changes in activities of key enzymes from basic metabolite pathways. Evidences, based on electrophoretic mobility, sensitivity to SOD inhibitors, and immunoblot analysis support the unusual existence of Cu/Zn-SOD in mitochondrial intermembrane space (IMS) while the Mn-SOD was in the matrix. Enzyme activity is almost equally partitioned between both compartments, thus suggesting that the IMS could be one of the major sites of exposure to superoxide anion radicals. The H. lutea mitochondrial Cu/Zn-SOD is the first identified naturally glycosylated enzyme, isolated from IMS.
3. Relationship between OS and other types of stresses
· Cu-induced stress. Our results provide additional evidences for OS mediating copper toxicity in filamentous fungi. Biomarker response to the heavy metal was quite equal with treatment involving a more direct application of ROS, such as paraquat. Adaptive response to heavy metal treatment refers to the ability of cells to better resist the damaging effects of the toxic agent when first preexposed to a lower dose.
· Heat-shock. Another particular area of interest concerns the hypothesis of a common signal for heat shock (HS) and OS. Evidence is provided for the possibility that the OS plays a major role in the effect of enhanced temperature in Aspergillus niger. The treatment resulted in increase in cyanide-resistant respiration, ROS generation, corresponding accumulation of the reserve carbohydrates (trehalose and glycogen), increase in protein carbonyl content, and activation of antioxidant enzyme defense. This knowledge may be of importance in controlling both fermentation and pathogenicity.
· Metabolite adaptation to cold temperatures. Antarctica and the life of filamentous fungi in the extreme environment are also an interest of our research group. The effect of temperature down shift on cell response of Antarctic fungi are comparing with this in European temperate strains. The main finding is that the fungal strains may have evolved a specialized physiology allowing them to survive prolonged low temperatures, and have enzyme systems that function at low temperatures. Compared to temperate mesophilic strains, Antarctic fungi (psychrophilicand mesophilic) demonstrated adaptations, which permit survival in low-temperature conditions.
· Stress of immobilization. Our results clearly demonstrated that immobilization influences the physiological behavior of fungal cells. Immobilized A. niger cells showed significant increase in activities of key enzymes of the glycolytic pathway, pentose shunt, and tricarboxylic acid cycle compared to the free cell culture. Moreover, immobilization elicits the enhanced synthesis of antioxidant enzymes that demonstrate an association between state of immobilization and oxidative stress.
4. Fungi as cell factories for production of valuable biological-active compounds
· Original fungal strains producers of biological-active compounds such as enzymes and alkaloids were isolated and characterized. We have a well-established expertise in production of elimoclavine, pectinase, proteinases etc. on laboratory and semi-industrial scale level.
· High effective technology for biosynthesis of naturally glycosylated Cu/Zn-SOD by the fungal strain Humicola lutea 103 (HLSOD) was elaborated. The novel enzyme exerts a far higher pharmacological activity than non-glycosylated enzymes. HLSOD was fully characterized and used in in vivo models for the demonstration of its protective effect against myeloid Graffi tumor in hamsters and influenza virus infection. Furthermore, the antioxidant enzyme improves fertility of ram and bull spermatozoa during liquid storage and cryoconservation.
· A new direction in our work are physiological and biochemical investigations of the biosynthesis and regulation of activity of valuable cold-active enzymes in psychrophilic and psychrotrophic fungi, using existing collections of Antarctic strains.
5. Fungal biodegradation of natural and synthetic polymers
Due to the current knowledge about morphology and biochemistry of the filamentous fungi, as well as the professional experience some methods concerning the preservation of natural polymers from fungal biodegradation were developed.
Granted by International Organizations
· Superoxide dismutase by Aspergillus niger: heat shock-induced biosynthesis and structural characterization (LST.CLG 980520, with Prof. B. Salvato, Padua, Italy); Science for Peace and Security, NATO.
· Effective education of PhD students and upport of development and realization of post-doctoral students and young scientists in priority areas of Microbiology (European Social Fund, Operational Programme “Human Resources Development”, grant BG051PO001-3.3.04/32.
· Cold-adaptation of Antarctic fungi and their application
(D-r . Tosi, University of Pavia, Italy)
· Biotechnological production of cold-active enzymes by fungi
(D-r . Tosi, University of Pavia, Italy)
·Study of the physiological, biochemical and ecological characteristics of micromycetes resistant to heavy metal stress
Project leader: M. Angelova, DSc
Project collaborator: V. Grishko, PhD, Ukrainian Academy of Sciences, Botanical Garden
· Efficacy of antimicrobial substances produced by streptomyces in modifying polymers used in conservation of paintings in some ancient egyptian tombs
Project leader: M. Angelova, DSc
Project collaborator: M. Farrag, PhD, Zagazig University, Faculty of Science, Botany Department, Egypt
Granted by National Funds
· Novel cold-active superoxide dismutase from Antarctic fungi:biotechnological production, chemical characterization and application (DO002-172/08), The National Science Fund of Ministry of Education and Science
· Molecular and biochemical analyses of Antarctic fungi strains: studies on the biodegradation ability to phenolic and poly-aromatic pollutants of the environment. (ДТК02-74/10), The National Science Fund of Ministry of Education and Science
· Wild small fruits species in Bulgaria - a valuable resource for human health (DО02-334/08), The National Science Fund of Ministry of Education and Science
· New ecotechnologies for biodegradation of organic waste with production of hydrogen and methane (DFNI-E02/13 with assoc. prof. Ivan Simeonov) The National Science Fund of Ministry of Education and Sciences
· Serkedjieva J., Stefanova Ts., and Krumova E. A Fungal Cu/Zn-Containing Superoxide Dismutase Enhances the Therapeutic Effi cacy of a Plant Polyphenol Extract in Experimental Influenza Virus Infection Z. Naturforsch. 65c., 2010, 419-428.
· Tosi S., Kostadinova N., Krumova E., Pashova S., Dishliiska V., Spassova B., Vassilev S., Angelova M. Antioxidant enzyme activity of filamentous fungi isolated from Livingston Island, Maritime Antarctica. Polar Biol. 33, 2010, 1227-1237.
· Engibarov, S., Eneva, R., Abrashev, R., Abrashev, I. Neuraminidase from environmental and clinical isolates of Aeromonas spp. - biochemical studies on the enzyme production Problems of Infectious and Parasitic Diseases 38 (1), 2010, pp. 37-39.
· Dineva, J., Vangelov, I., Abrashev, R., (...), Angelova, M., Ivanova, M.Survival role of intracellular superoxide dismutases sods and catalase for human granulosa luteinized cells. A preliminary study. Comptes Rendus de L'Academie Bulgare des Sciences 63 (10), 2010, pp. 1463-1470.
· Miteva-Staleva J., Stefanova T., Krumova E., Angelova M. Growth-phase related changes in reactive oxygen species generation as a cold stress response in Antarctic Penicillium strains, Biotechnology & Biotechnological Equipment 25(4), 2011, 58-63.
· Dolashka, P., Moshtanska, V., Dolashki, A., (...), Voelter, W., Atanasov, B. Structural analysis and molecular modelling of the Cu/Zn-SOD from fungal strain Humicola lutea 103. Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy 83 (1), 2011, pp. 67-73.
· Kostadinova, N., Vassilev, S., Spasova, B., Angelova, M. Cold stress in Antarctic fungi targets enzymes of the glycolytic pathway and tricarboxylic acid cycle. Biotechnology and Biotechnological Equipment 25 (SUPPL. 4), 2011, pp. 50-57.
· Dineva, J., Vangelov, I., Abrashev, R., (...), Angelova, M., Ivanova, M.Survival role of superoxide dismutase 1 on human granulosa luteinized cells in vitro. Endocrine Regulations 45 (4), 2011, pp. 175-181.
· Georgiev M., Alipieva K., Orhan I., Abrashev R., Denev P., Angelova M. Antioxidant and cholinesterases inhibitory activities of Verbascum xanthophoeniceum Griseb and its phenylethanoid glycosides. Food Chemistry 128(1), 2011, 100–105, ISSN 0097-6156.
· Eneva, R., Engibarov, S., Strateva, T., Abrashev, R., Abrashev, I. Biochemical studies on the production of neuraminidase by environmental isolates of vibrio cholerae non-o1 from Bulgaria. Canadian Journal of Microbiology 57 (7), 2011, pp. 606-610.
· Abrashev R., Krumova E., Dishliska V., Eneva R., Engibarov S., Abrashev I., Angelova M. Differential effect of paraquat and hydrogen peroxide on the oxidative stress response in Vibrio cholera NON O1 26/06. Biotechnology & Biotechnological Equipment 25(SUPPL. 4), 2011, 72-76.
· Krumova E. , Pashova S., Dolashka-Angelova P. and Angelova M. Adaptive response of Humicola lutea to copper exposure Biotechnology & Biotechnological Equipment, 25, (SUPPL. 4), 2011, 64-71.
· Dineva, J., Vangelov, I., Todorova, K., (...), Angelova, M., Ivanova, M. Study on the relationship between the activity of the antioxidant enzymes superoxide dismutase and catalase in granulosa luteinized cells with controlled ovarian hyperstimulation/in-vitrofertilization outcome in infertile women Comptes Rendus de L'Academie Bulgare des Sciences 65 (2), 2012, pp. 181-186
· Krumova E., Stoitsova T., Paunova Ts., Pashova S., Angelova M. Copper stress and filamentous fungus Humicola lutea 103: Ultrastructural changes and activities of key metabolic enzymes.Canadian Journal of microbiology 58(12) , 2012, 1335-1343.
· Kostadinova N., Krumova E., Stefanova T., Dishliyska V., Angelova M. Transient cold shock induces oxidative stress events in Antarctic fungi. In Oxidative Stress/Book 3, eds. Volodymyr I. Lushchak and Oksana Stoliar, InTech, 2012, p. 75-99.
· Krumova E., Abrashev R., Kostadinova N., Dishlijska V., Miteva-Staleva J., Pashova S., Vasilev S., Spasova B., Stephanova L., Angelova M. Novel cold-active antioxidant enzymes from Antarctic fungi New trends in microbiology, 2012, р. 291-305.
· Kostadinova N., Krumova E., Pashova S., Miteva-Staleva J., Abrashev R., Tosi S., Stoitsova S., Manasiev J., Angelova M. Cold-stress adaptation in Antarctic fungi. New trends in microbiology, 2012, р. 159-175.
· Krumova E., Abrashev R., Miteva-Staleva J., Pashova S., Angelova M. Regulation of superoxide dismutase synthesis in Humicola lutea cells under Cu2+ stress conditions. Compt. rend. Acad. bulg. Sci., 66 (4), 2013, 525-533.
· Maggi, O., Tosi, S., Angelova, M., (...), Vizzini, A., Buzzini, P. Adaptation of fungi, including yeasts, to cold environments Plant Biosystems 147 (1), 2013, pp. 247-258.
· Abrashev R., Stoitsova S., Krumova E., Pashova S., Paunova-Krasteva Ts., Vassilev S., Dolashka-Angelova P., Angelova M. Temperature-stress tolerance of the fungal strain Aspergillus niger 26: physiological and ultrastructural changes World Journal of Microbiology and Biotechnology 30 (5), 2014, 1661-1668.
· Abrashev R., Stoitsova S., Krumova E., Pashova S., Paunova-Krasteva Ts., Vassilev S., Dolashka-Angelova P., Angelova M. Temperature-stress tolerance of the fungal strain Aspergillus niger 26: physiological and ultrastructural changes. World Journal of Microbiology and Biotechnology: 30(5), 2014, 1661-1668
· Mileva M., Krumova E., Miteva-Staleva J., Kostadinova N., Dobreva A., Galabov A.S. Chemical Compounds, In Vitro Antioxidant and Antifungal Activities of Some Plant Essential Oils Belonging to Rosaceae Family. Comptes rendus de l’Acade'mie bulgare des Sciences, 67 (10), 2014, 1363-1368.
· Lazarova N., Krumova E., Stefanova Ts., Georgieva N., Angelova M. (2014): The oxidative stress response of the filamentous yeast Trichosporon cutaneum R57 to copper, cadmium and chromium exposure, Biotechnology & Biotechnological Equipment, DOI: 10.1080/13102818.2014.965020
· Семерджиева Н., Денчев С., Абрашев Р., Цанкова А., Христова Ж., Стойчева В. Характеристика на острите коронари синдроми при жени: оксидативен стрес и миокардно увреждане, Списание българска кардиология 2014 ХХ 14-21
· Gryshko VM, Kopinovska OM, Krumova ETz, Angelova M. Resistance of the micromycetes isolated from the chernozem usual and technozems, to joint influence of cadmium, nickel, copper, zinc and lead. Reports of the National Academy of Sciences of Ukraine, 2014, 10, 144-153