Статті

Постійне посилання на розділhttps://dspace.nuft.edu.ua/handle/123456789/7372

Переглянути

Результати пошуку

Зараз показуємо 1 - 2 з 2
  • Ескіз
    Документ
    Influence of biological inductors on the synthesis and biological activity of microbial metabolites
    (2023) Pirog, Tatiana; Ivanov, Mykyta
    The increasing antibiotic resistance is a severe concern for humanity. Co-cultivation of microorganisms is a promising method for obtaining new secondary antimicrobial metabolites. An effective strategy for co-cultivation of microorganisms involves the usage of certain biological inductors. The aim of this review is to summarize existing scientific research in the literature related to the influence of physiologically different types of biological inductors on the synthesis and biological activity of microbial secondary metabolites. An analysis of the literature has shown that in such studies, either live or inactivated cells of the inductor are added to the culture medium at significantly lower concentrations compared to the producer cells of the final metabolites, or the supernatant (filtrate) after cultivation of a competitive microorganism is used as an inductor. According to the literature and our own experimental studies, the using inductors is an effective approach not only for intensifying the synthesis of bacteriocins, surfactants, and antibiotics, but also for increasing their biological activity. Additionally, it often leads to the production of novel antimicrobial compounds that are not typical for the producer. However, the mechanisms of effect of inductors on the synthesis of biologically active secondary metabolites require further research, as the literature suggests that their introduction into the cultivation medium of producer does not always lead to an intensification of the synthesis of the final product. Moreover, the biological activity of secondary metabolites depends on the cultivation conditions of the producer, including the presence of biological inductors in the culture medium. Therefore, it is essential to conduct further research on the interaction between producers and competitive microorganisms to regulate the biological activity of the synthesised metabolites. In addition, there is a necessity to search for more cost-effective substrates for the biosynthesis of secondary metabolites, optimize the composition of the culture medium and expand the range of both pro- and eukaryotic inductors
  • Ескіз
    Документ
    Destruction of biofilms under the influence of Acinetobacter calcoaceticus IMV B-7241 surfactants, synthesized in the presence of competitive microorganisms
    (2022) Pirog, Tatiana; Ivanov, Mykyta
    Introduction. The aim of this study was to investigate the role of surfactants synthesized by Acinetobacter calcoaceticus IMV B-7241 in media with glycerol in the presence of biological inductors in destruction of biofilms. Materials and methods. Cultivation of A. calcoaceticus IMV B-7241 was carried out in a mineral medium using refined glycerol or crude glycerol, the waste of biodiesel production, as carbon sources. Biological inductors were introduced as live or inactivated cells of Bacillus subtilis BT-2, as well as the supernatant after strain BT-2 cultivation. Surfactants were extracted from the supernatant of the culture liquid with a modified mixture of Folch (chloroform and methanol, 2:1). The degree of biofilm destruction in the presence of surfactants was determined by spectrophotometric method. Results and discussion. Regardless of the substrate used, the introduction of both live and inactivated cells of B. subtilis BT-2 into medium used for cultivation of A. calcoaceticus IMV B-7241 was accompanied by the synthesis of surfactants, the degree of biofilm destruction of which was higher than those obtained in the medium without an inductor. The degree of destruction of bacterial and yeast biofilms achieved by the action of A. calcoaceticus IMV B-7241 surfactants obtained on refined glycerol in the presence of inductor cells was 36.5–85% and was 1.5-3 times higher compared to using surfactants synthesized in medium without inductors. Note that, surfactants synthesized in the presence of biological inductors destroyed biofilms of the test cultures at fairly low (7.5–960 μg/ml) concentrations. Similar results were observed for the usage of surfactants obtained on the waste of biodiesel production. Therefore, introduction of live cells of B. subtilis BT-2 into the medium with the crude glycerol was accompanied by synthesis of surfactants, which at concentration 1.8-960 μg/ml caused destruction of B. subtilis BT-2, Proteus vulgaris PA-12 and Enterobacter cloacae C-8 biofilms at 30.1–80.7% and was higher than using similar surfactant concentrations obtained during cultivation without inductors (24.1–75%). The destruction of biofilms of Staphylococcus aureus BMS-1, Candida albicans D-6 and Candida tropicalis PE-2 under the action of surfactants (1.8-960 μg/ml) synthesized on crude glycerol in the presence of both live or inactivated cells of B. subtilis BT-2 was 1.5–8 times higher than surfactants synthesized in medium without inductor. Conclusion. The possibility to regulate the ability to destroy bacterial and yeast biofilms of surfactants synthesized by A. calcoaceticus IMV B-7241 by introducing into the medium competitive bacteria B. subtilis BT-2 was found.