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Документ Biological activity of Acinetobacter calcoaceticus IMV B-7241 surfactants synthesized in the presence of competitive bacteria Bacillus subtilis BT-2(2023) Pirog, Tatiana; Ivanov, Mykyta; Shevchuk, TetianaCurrently, the effectiveness of technologies of microbial surfactant, which are characterized by a complex of practically valuable physicochemical and biological properties, is lower than that of synthetic analogues. To reduce the cost of these products of microbial synthesis, industrial waste is used as substrates for their biosynthesis. In previous studies, it was established that surfactants synthesized by Acinetobacter calcoaceticus IMV B-7241 on crude glycerol had lower antimicrobial activity compared to those obtained on purified glycerol. The main approaches to the regulation of the biological activity of microbial surfactants are their post-fermentation chemical modification, as well as the improvement of producer strains by methods of metabolic and genetic engineering. In recent years, the great amount of studies have appeared on the co-cultivation of producers of antimicrobial compounds with competitive microorganisms (biological inductors), in response to the presence of which the antimicrobial activity of the final product increases. Aim. To study the effect of live and inactivated cells of Bacillus subtilis BT-2, as well as the corresponding supernatant, on the antimicrobial, anti-adhesive activity and the ability to destroy biofilms of A. calcoaceticus IМV B-7241 surfactants, synthesized in a medium with glycerol of different degrees of purification. Methods. The IMV B-7241 strain was grown in the liquid mineral medium with purified and crude glycerol, into which live and inactivated B. subtilis BT-2 cells, as well as the supernatant after growing the BT-2 strain (2.5−10%, v/v) were added. Surfactants were extracted from the supernatant of the culture liquid with Folch's mixture. Anti-adhesive activity and the degree of destruction of biofilms were determined by the spectrophotometric method, antimicrobial activity − by the indicator of the minimum inhibitory concentration. The activity of enzymes of surface-active aminolipids biosynthesis (NADP+-dependent glutamate dehydrogenase) and glycolipids (phosphoenolpyruvate (PEP)-carboxylase, PEP-synthetase, PEP-carboxykinase, trehalose-phosphate synthase) was analyzed in cell-free extracts obtained after сells sonication. Results. It was established that the introduction of inactivated B. subtilis BT-2 cells and supernatant into the medium with both substrates did not affect the indicators of the surfactants synthesis, while in the presence of live cells of the BT-2 strain in the medium with purified glycerol, a decrease in the concentration of the final product by 1.5 times, and in the culture medium with crude glycerol - an increase of 1.4 times were observed compared to the indicators without the inductor. The study of the antimicrobial activity of surfactants showed that the most effective of the used inductors (live, inactivated cells, supernatant) were live cells of B. subtilis BT-2. The introduction of BT-2 strain live cells into the culture medium with both substrates was accompanied by the formation of surfactants, the minimum inhibitory concentrations of which in relation to bacterial (Bacillus subtilis BT-2, Staphylococcus aureus BMS-1, Proteus vulgaris PA-12, Enterobacter cloacae С-8 ) and yeast (Candida albicans D-6, Candida tropicalis PE-2) test-cultures were 3-23 times lower than established for those synthesized on the medium without this inductor. Anti-adhesive activity of surfactants obtained on purified and crude glycerol in the presence of all types of inductors was higher than those synthesized in the culture medium without inductors (cells adhesion of bacterial and yeast test-cultures on polyvinyl chloride was 13−70 and 33−96%, respectively). Introduction into A. calcoaceticus IMV B-7241 medium cultivation of both live and inactivated B. subtilis BT-2 cells, as well as the supernatant, was accompanied by the synthesis of surfactants in the presence of which the disruption of bacterial biofilms was on average 10-20 % higher compared to using surfactants synthesized without an inductor. In the presence of B. subtilis BT-2 in the medium, in the cells of the IMV B-7241 strain the activity of NADP+-dependent glutamate dehydrogenase (a key enzyme of aminolipids biosynthesis) increased by 1.5-2 times, while the activity of glycolipids enzymes biosynthesis remained practically at the same level as without an inductor. Such data indicated that the higher biological activity of surfactants obtained by A. calcoaceticus IMV B-7241 in the presence of biological inductors might be due to an increase in the content of aminolipids in their composition. Conclusions. As a result of research, it was established the possibility of regulating the antimicrobial and anti-adhesive activity, as well as the ability to disrupt biofilms of A. calcoaceticus IМV B-7241 surfactants by introducing into the culture medium of competitive bacteria B. subtilis BT-2. It is important that under such cultivation conditions the antimicrobial activity of surfactants synthesized on toxic crude glycerol significantly increased.Документ The properties of surfactants synthesized by Acinetobacter calcoaceticus ІMV В-7241 on refined and sunflower oil waste(2018) Pirog, Tatiana; Lutsay, Dariya; Antoniuk, Svitlana; Elperin, IgorThe aim of the work was to compare the antimicrobial and anti-adhesive activity (including the ability to destroy biofilms), as well as the effect on oil degradation of the surfactants synthesized by the culture of Acinetobacter calcoaceticus IMV B-7241 on refined and sunflower waste. The microbial surfactants were extracted from supernatant of cultural liquid by mixture of chloro form and methanol (2:1). The number of attached cells and the degree of biofilm destruction were analyzed spectrophotometrically. Antimicrobial properties of the surfactants were determined by index of the minimal inhibiting concentration. The concentration of oil in water was analyzed by the gravimetric method after extraction with hexane. It was shown that microbial surfactants synthesized in medium with 2% of both refined and fried oil were characterized by high antimicrobial (MIC with respect to bacterial test cultures 0.8–29 μg/ml, Candida albicans D-6 26−58 μg/ml) and anti-adhesive (decreasing number of bacterial and fungal cells of test cultures attached to abiotic surfaces by 35–70%, destruction of biofilms by an average of 40–44%) activity. Increasing concentration of waste oil in the medium to 4% was accompanied by the formation of surfactants with low antimicrobial activity, in the presence of which the degree of oil destruction in water (3–6 g/l) was 80–88% in 20 days, which is 10–16% higher than when using surfactants synthesized in a medium with 2% oil. Obtained data indicate on the need for studies on the effect of cultivation conditions of producer on the properties of synthesized surfactants for the production of final product with stable predetermined properties, depending on the field of practical application. Метою роботи було порівняти антимікробну та антиадгезійну активність (у тому числі здатність руйнувати біоплівки), а також вплив на деградацію олії ПАР, синтезованих культурою Acinetobacter calcoaceticus ІМВ В-7241 на рафінаді та соняшнику. відходи. Мікробні поверхнево-активні речовини екстрагували із супернатанту культуральної рідини сумішшю хлороформи та метанолу (2:1). Кількість прикріплених клітин і ступінь руйнування біоплівки аналізували спектрофотометрично. Антимікробні властивості ПАР визначали за показником мінімальної інгібуючої концентрації. Концентрацію олії у воді аналізували гравіметричним методом після екстракції гексаном. Показано, що мікробні ПАР, синтезовані на середовищі з 2% як рафінованої, так і смаженої олії, характеризуються високою антимікробною дією (МІК щодо бактеріальних тест-культур 0,8–29 мкг/мл, Candida albicans D-6 26–58 мкг/мл). антиадгезивну (зменшення кількості бактеріальних і грибкових клітин тест-культур, прикріплених до абіотичних поверхонь, на 35–70%, руйнування біоплівок у середньому на 40–44%). Підвищення концентрації відпрацьованої нафти в середовищі до 4 % супроводжувалося утворенням поверхнево-активних речовин із низькою антимікробною активністю, у присутності яких ступінь деструкції нафти у воді (3–6 г/л) у 20 р. становив 80–88 %. днів, що на 10–16 % вище, ніж при використанні ПАР, синтезованих у середовищі з 2 % олії. Отримані дані свідчать про необхідність дослідження впливу умов культивування продуцента на властивості синтезованих ПАР для отримання кінцевого продукту зі стабільними заданими властивостями в залежності від галузі практичного застосування.Документ Industrial waste bioconversion into surfactants by Rhodococcus erythropolis IMV Ac-5017, Acinetobacter calcoaceticus IMV B-7241 and Nocardia vaccinii IMV B-7405(2017) Pirog, Tatiana; Shulyakova, Mariya; Kliuchka (Nykytyuk), Lilia; Antoniuk, Svitlana; Elperin, IgorThe aim of the work is to realize an alternative processing of toxic industrial waste into surfactants by strains Rhodacoccus erythropolis IMV Ac-5017, Acinetobacter calcoaceticus IMV B-7241 and Nocardia vaccinii IMV B-7405 for remediation of environment. The studied strains were grown in liquid media containing such sources of carbon as waste (fried) sunflower oil. technical glycerol (by product of biodiesel production), and aromatic compounds. The synthesis of surfactants was evaluated by emulsification index. conditional concentration of surfactants and concentration of extracellular surfactants, which was determined gravimetrically after their extraction from supernatant by the mixture of methanol and chloroform. The concentration of oil in water and soil was analyzed by gravimetric method after extaction with hexane.Документ The prospects of using bacteria of the genus Rhodococcus and microbial surfactants for the degradation of oil pollutants(2006) Vildanova-Marcishin, R.; Karpenko, Elena; Shcheglova, N.; Pirog, Tatiana; Voloshina, IrynaThe possibility of accelerating oil degradation by an enrichment culture of oil-oxidizing microorganisms in the presence of bacteria of the genus Rhodococcus and microbial surfactants was studied. It was shown that the degree of consumption of crude oil (2vol %) after 192 h of enrichment culture growth reached 84%. Inoculation of the active hydrocarbon-oxidizing strain Rhodococcus erythropolis EK-1 and exogenous surfactants produced by Pseudomonas sp. PS-27 increased this degree to 90 and 93–94%, respectively. On the grounds of these results, efficient methods of purification of the environment from oil pollutants can be developed.