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CHISELIŢĂ, Oleg; BÎRSA, Maxim; BURŢEVA, Svetlana; MAŞCENCO, Natalia. Influence of vegetal iridoid glycosides on the viability of streptomyces after lyophilization. In: Microbial Biotechnology. Ediția 4, 11-12 octombrie 2018, Chișinău. Chișinău, Republica Moldova: Institutul de Microbiologie şi Biotehnologie, 2018, pp. 164-165. ISBN 978-9975-3178-8-7.
Ediția 4, 2018
Conferința "Microbial Biotechnology" |
Chișinău, Moldova, 11-12 octombrie 2018
Currently, due to increasing demand, researchers from different areas of biology emphasize the need to obtain new natural substances with high biological activity. In in recent years, vegetal iridoid glycosides extracts have been studied more and more frequently, in this context. Thanks to immunomodulatory, antiinflammatory, antihepatotoxic, choleretic, hypoglycemic, antispasmolytic, antioxidant activity, these substances are used for the preparation of various pharmaceuticals. Iridoid glycosides are increasingly used in plant protection, due to their antiviral, and adaptogenic properties; positive influence on seed germination, tissue regeneration and cell membrane protection by reducing lipid peroxidation. Some of these properties justify the use of vegetable glycosides as lyoprotectants for the preservation of microorganisms. Choosing the right methods for micro-organisms preservation is one of the main tasks of microbial culture collections. Currently, freeze-drying and cryopreservation are considered by researchers the most effective and long-lasting methods of preserving strains of scientific and biotechnological interest. The genetic stock of industrial microorganisms represents for Moldova an inexhaustible natural resource, the national patrimony. Storing, maintaining viability and long-lasting stabilization of taxonomic characters of microorganisms with beneficial scientific and technological use, is the main objective of the CNMN and of all collections all around the world. According to the literature data, the microorganism viability reduction during preservation could be induced by the free radicals formation. Some authors consider that their appearance is determined by both the change in the ratio between different forms of water in the cell and the destruction of the polypeptide chains. According to other opinions, this process takes place due to oxidation reactions. Thus, both free radicals and oxidative lipid products, interacting with cell membranes, lead to lesions causing the cell death. In order to avoid cell death during lyophilization, the used protective media usually contain substances with cryoprotective properties, membrane stabilization and antioxidant activity. Based on the above, the purpose of the research was to evaluate the influence of vegetal glycosidic extracts from Verbascum phlomoides (L.) and Linaria genistifolia (L.) Mill. on the viability of streptomycetes after lyophilization and long-term storage. The subject of the study was the strain Streptomyces canosus CNMN-Ac-02. The above mentioned glycosidic extracts in concentrations of 0.00005-0.05% / V were tested as lyoprotectors added to the protective medium - 2.5% gelatin + 7.5% glucose (control medium). In previous researches was demonstrated the lyoprotective effect of oligo-peptide and polysaccharide cyanobacterial extracts, which increase the viability of streptomyces up to 20.1- 38.0% after lyophilization and up to 28.3-39.8% after 1 preservation cycle compared to the blank test. The efficacy of the iridoid glycosides proved to be even higher. Thus, supplementation of the standard medium with glycosides in concentrations up to 3 orders less than cyanobacterial extracts resulted in the increase of the studied strain viability relative to the reference samples up to 10.1% after lyophilization and up to 5.4% after 1 year of conservative use of verbascosides and 18.0 and 16.6% respectively when using genistifoliasides. The innovative character of these researches is evidenced by the patents for invention (MD 1226, MD 1235). Thus, we can conclude that glycosidic extracts positively influence the viability of streptomyces and can be used in the composition of protective media for the preservation of microorganisms by lyophilization. The results of these researches will serve to optimize the methods for the long-term preservation and storage of the CNMN microbial gene pool.