The effect of co-cultivation of Rhodococcus erythropolis with other bacterial strains on biological activity of synthesized surface-active substances.

Surface-active substances synthesized by Rhodococcus erythropolis ІMВ Ас-5017 during co-cultivation with inducing bacteria either Bacillus subtilis BT-2 or Escherichia coli ІЕM-1 (SASI) had the higher antimicrobial and antiadhesive activities in comparison with surface-active substances synthesized in the medium without cells of inducing bacteria (SAS). Minimum inhibitory concentrations of SASI ranged from 3 to12 μg/mL and were in 4-32 times lower than the same parameter for SAS. Treatment of abiotic surfaces (ceramic, steel, and glass) with SASI decreased adhesion of bacteria Staphylococcus aureus BMC-1 or yeasts Candida albicans D-6 to the level of 10-32 % in comparison with 32-87 % after treatment of surfaces with SAS.

[Biological Properties of Nocardia vaccinii IMV B-7405 Surfactants Synthesized on Byproduct of Biodiesel Production].

Aim: Comparison of antimicrobial and anti-adhesive activity of Nocardia vaccinii ІMV B-7405 surfactants synthesized on purified and technical glycerol (byproduct of biodiesel production).

Methods: Surfactants were extracted from supernatant of cultural liquid by mixture of chloroform and methanol (2:1). Antimicrobial against bacteria and yeast properties of the surfactant was determined by index of the minimum inhibitory concentration (MIC).

[EFFECT OF Zn²⁺ ON SYNTHESIS OFACINETOBACTER CALCOACETICUS IMV B-7241 SURFACTANTS WITH ANTIMICROBIAL AND ANTIADHESIVE PROPERTIES].

Aim: To study the effect of zinc cations in the composition of ethanol and n-hexadecane containing medium on the antiadhesive and antimicrobial activity of Acinetobacter calcoaceticus IMV B-7241 surfactants.

Methods: Surfactants were extracted from supernatant of cultural liquid by mixture of chloroform and methanol (2:1). The number of attached cells was determined spectrophotometrically, antimicrobial properties - by index of the minimum inhibitory concentration (MIC).

[Antimicrobial Properties Surfactants Synthesized under Different Cultivation Conditions of Acinetobacter calcoaceticus EMV B-7241].

Aim: To study the antimicrobial properties of the surface-active agents (surfactants) Acinetobacter calcoaceticus IMV B-7241 depending on the availability of yeast autolysate and trace elements in the composition of ethanol-, n-hexadecane- and glycerol-containing media.

Methods: Antimicrobial against bacteria (Escherichia coli IEM-1, Bacillus subtilis BT-2), and yeast (Candida albicans D-6) properties of the surfactant was determined by index of the minimum inhibitory concentration (MIC). Surfactants were extracted from supernatant of cultural liquid by mixture of chloroform and methanol (2:1).

[Biological Properties of Nocardia vaccinii IMV B-7405 Surfactants Synthesized on Fried Sunflower Oil].

Aim: To study of antimicrobial and antiadhesive properties of the surface-active substances (surfactants) Nocardia vaccinii IMV B-7405 synthesized on different oil-containing substrates (refined and waste after frying meat and potatoes sunflower oil).

Methods: Surfactants were extracted from supernatant of cultural liquid by mixture of chloroform and methanol (2 : 1). Antimicrobial against bacteria and yeast properties of the surfactant was determined by index of the minimum inhibitory concentration (MIC).

[SYNTHESIS OF PHYTOHORMONES BY NOCARDIA VACCINII IMV B-7405--PRODUCER OF SURFACTANTS].

Aim: To study the synthesis of phytohormones (auxins, cytokinins, abscisic acid) under cultivation of Nocardia vaccinii IMV B-7405 (surfactants producer) in media containing different carbon sources (glycerol, refined sunflower oil, as well as waste oil after frying potatoes and meat).

Methods: Phytohormones were extracted from supernatants of culture liquid (before or after surfactant separation) by ethylacetate (auxins, abscisic acid) and n-butanol (cytokinins), concentrated and purified by thin-layer chromatography, then quantitative determination was performed using a scanning Sorbfil spectrodensitometer.

Results: While growing in medium with refined oil IMV B-7405 strain synthesized 1.

[ANTIMICROBIAL ACTION OF NOCARDIA VACCINII IMV B-7405 SURFACTANTS].

Aim: To study the effect of Nocardia vaccinii IMV B-7405 surfactants on some bacteria (including pathogens of genera Proteus, Staphylococcus, Enterobacter), yeast of Candida species and fungi (Aspergillus niger R-3, Fusarium culmorum T-7).

Methods: The antimi- crobial properties of surfactant were determined in suspension culture by Koch method and also by index of the minimum inhibitory concentration. Surfactants were extracted from supernatant of cultural liquid by mixture of chloroform and methanol (2:1).

[EFFECT OF CULTIVATION CONDITION OF ACINETOBACTER CAL COACETICUS IMV B-7241 ON ANTIADHESIVE PROPERTIES OF SURFACTANTS].

Aim: To study the effect of growth factors and microelements in composition of ethanol-, n-hexadecane- and glycerol-containing media on antiadhesive properties of A cinetobacter calcoaceticus IMV B-7241 surfactants.

Methods: Surfactants were extracted from supernatant of cultural liquid by mixture of chloroform and methanol (2:1). The number (%) of attached cells (adhesion) was determined as a ratio of the optical density of the suspension obtained from the materials treated with surfactants to the optical density of the control samples (100 %).

[GLUCOSE METABOLISM IN SURFACTANTS PRODUCER NOCARDIA VACCINII IMV B-7405].

Key enzymes of glucose metabolism were detected in the cells of surfactants producer Nocardia vaccinii IMV B-7405 grown on this substrate. It has been established that glucose catabolism is performed through gluconate (FAD(+)-dependent glucose dehydrogenase activity 698 ± 35 nmol x min(-1) x mg(-1) of protein). Oxidation of gluconate to 6-phosphogluconate is catalised by gluconokinase (178 ± 9 nmol x min(-1) x mg(-1) of protein).

[PECULIARITIES OF GLUCOSE AND GLYCEROL METABOLISM IN Nocardia vaccinii IMB B-7405].

It has been established that in cells of Nocardia vaccinii IMB B-7405 (surfactant producer) glucose catabolism is performed through pentose phosphate cycle as well as through gluconate (activity of NAD+-dependent glucose-6-phosphate dehydrogenase and FAD+-dependent glucose dehydrogenase 835 ± 41 and 698 ± 35 nmol.min-1.mg-1 of protein respectively).

[BIOCONVERSION OF CRUDE GLYCEROL AND MOLASSES MIXTURE IN BIOSURFACTANTS OF NOCARDIA VACCINII IMB B-7405].

The possibility of replacing glucose and pure glycerol in mixed substrates for surtace-active substances (SAS, biosurfactants) biosynthesis of Nocardia vaccinii IMB B-7405 on molasses (sugar production waste) and crude glycerol (by-product of biodiesel production) was established. It was established that the increasing concentration of crude glycerol to 6% in mixture with 1.0% molasses was accompanied by increase of amount of SAS synthesized more than twice, and the increasing content of molasses to 3.

[Destruction of oil in the presence of Cu2+ and surfactants of Acinetobacter calcoaceticus IMV B-7241, Rhodococcus erythropolis IMV Ac-5017 and Nocardia vaccinii IMV B-7405].

The effect of copper cations (0.01-1.0 mM) and surface-active agents (surfactants) of Acinetobacter calcoaceticus IMV B-7241, Rhodococcus erythropolis IMV Alc-5017 and Nocardia vaccinii IMV B-7405 in the form of culture liquid on the destruction of oil in water (3.

[Antiadhesive properties of the surfactants of Acinetobacter calcoaceticus IMB B-7241, Rhodococcus erythropolis IMB Ac-5017, and Nocardia vaccinii IMB B-7405].

Attachment of the cells of some bacteria, yeasts, and micromycetes to various surfaces (catheters, dentures, plastic, polyvinyl chloride, tiles, and steel) treated with the surfactants fromAcinetobacter calcoace- ticus IMB B-7241, Rhodococcus erythropolis IMB Ac-5017, and Nocardia vaccinii IMB B-7405 was studied. Adhesion of microorganisms to all the studied surfaces depended on the surfactant concentration and purity, kind of surface, and the test culture. Treatment with the surfactants from N.

[Antiadhesive potencial of Rhodococcus erythropolis IMB Ac-5017 biosurfactants].

The effect of Rhodococcus erythropolis IMB Ac-5017 biosurfactants (surface-active substances, SAS) with different degree of purification on attachment of bacteria (Escherichia coli IEM-1, Bacillus subtilis BT-2, Proteus vulgaris BT-1, Staphylococcus aureus BMC-1, Pseudomonas aeruginosa P-55, Enterobacter cloacae AC-22, Erwinia aroidaeae B-433), yeasts (Candida albicans D-6) and fungi (Aspergillus niger P-3, Fusarium culmorum T-7) to the abiotic surfaces (glass, plastic, ceramics, steel, linoleum) was studied. The dependence of microorganisms adhesion on degree of SAS purification (supernatant, purified SAS solution), SAS concentration (0,04-1,25 mg/ml), type of surface and test-cultures was established. The adhesion of majority investigated bacterial cells after treatment of abiotic surfaces with supernatant of cultural liquid with SAS concentration 0,06-0,25 mg/ml was on the average 20-45, yeasts C.

[Influence of heavy metals on surfactants synthesis by Nocardia vaccinii IMV B-7405].

The production of surfactants by Nocardia vaccinii IMV B-7405 in glycerol -and hydrocarbon-containing medium after addition Cd(3+) Pb(2+) and Cu(2+) was investigated. It was established that the introduction of 0.1 mM Cu(2+) in the exponential growth phase of IMV B-7405 strain or simultaneous addition of Cu(2+) (0.

[Synthesis of surfactants by Rhodococcus erythropolis IMV Ac-5017, Acinetobacter calcoaceticus IMV B-7241 and Nocardia vaccinii IMV B-7405 on industrial waste].

The synthesis of surfactants by Rhodococcus erythropolis IMV Ac-5017, Acinetobacter calcoaceticus IMV B-7241 and Nocardia vaccinii IMV B-7405 on industrial waste (food and oil-processing industry, production of biodiesel) was investigated. The possibility of replacing the expensive substrates (n-hexadecane and ethanol) by industrial waste (oil and fat industry, fried sunflower oil, glycerol, liquid paraffin) for the surfactant biosynthesis was established. The conditional concentration of surfactants was maximal on oil containing substrates and exceeded those on n-hexadecane and ethanol 2-3 times.

[Effect of growth factors and some microelements on biosurfactant synthesis of Acinetobacter calcoaceticus IMV B-7241].

The effect of yeast autolysate and microelements on synthesis of surface-active substances (SAS, biosurfactants) was investigated under cultivation of Acinetobacter calcoaceticus IMV B-7241 on various carbon substrates (n-hexadecane, ethanol, glycerol). The authors have shown a possibility to substitute the yeast autolysate and microelement mixture in the composition of ethanol- and n-hexadecane-containing media by copper sulfate (0.16 micromol/l) and iron sulfate (3.

[Effect of surface-active substances of Acinetobacter calcoaceticus IMV B-7241, Rhodococcus erythropolis IMV Ac-5017, and Nocardia vaccinii K-8 on phytopathogenic bacteria].

The effect of surface-active substances (SAS's) of Acinetobacter calcoaceticus IMV B-7241, Rhodococcus erythropolis IMV Ac-5017, and Nocardia vaccinii K-8 on phytopathogenic bacteria has been studied. It was shown that the survival of cells (10(5)-10(7) in a milliliter) of the Pseudomonas and Xanthomonas phytopathogenic bacteria was found to be 0-33% after treatment with SAS preparations of the IMV Ac-5017 and IMV B-7241 strains for 2 h (0.15-0.

[Intensification of surfactants synthesis by Nocardia vaccinii K-8 on crude glycerol].

The authors studied the effect of components of crude glycerol (potassium and sodium salts, ethanol, methanol) - the by-products of biodiesel production on formation of surfactants (surface-active substances, SAS) by Nocardia vaccinii K-8, as well as possibility to intensify the SAS synthesis by the strain K-8 on crude glycerol in the presence ofbiosynthesis precursors (glucose, sun-flower oil, organic substances). It has been established that the introduction of potassium (sodium) chloride in concentration 2.5 % and ethanol (methanol) in concentration 0.

[Influence of pH on synthesis of Acinetobacter calcoaceticus IMV B-7241 biosurfactants].

Synthesis of extracellular metabolites with surface-active and emulsifying properties, pH being maintained at the level of 5.8-8.0, in the process of cultivation of Acinetobacter calcoaceticus IMV B-7241 in the medium with ethanol (2%, volume part) was investigated.

[Effect of univalent cations on synthesis of surfactants by Acinetobacter calcoaceticus IMV B-7241].

The effect of univalent cations on activity of key enzymes of C2-metabolism has been investigated in the producer of biosurfactants, Acinetibacter calcoaceticus IMV B-7241 grown on ethanol. It was established that potassium cations are inhibitors of pyroquinolinequinone-dependent alcohol- and acetaldehyde dehydrogenases, the enzymes of biosynthesis of surface-active aminolipids (NADP-dependent glutamate dehydrogenase) and glycolipids (phosphoenopyruvate (PhEP)-carboxikinase), while ammonium cations are activators of these enzymes and PhEP-carboxylase. A decrease of potassium cations concentration in the cultivation medium to 1 mM and increase of the content of amine nitrogen to 10 mM as a result of potassium nitrate substitution by equimolar, as to nitrogen, urea concentration were accompanied by the increase of activity of enzymes of ethanol metabolism and SAS biosynthesis, as well as by the 2-fold increase of conditional concentration of the biosurfactants.

Biosurfactants of Rhodococcus erythropolis IMV Ас-5017: synthesis intensification and practical application.

Intensification of the surfactant synthesis by Rhodococcus erythropolis IMV Ac-5017 on different substrates, including industrial waste, as well as the use of surfactant preparations for oil degradation were studied. It was established that the addition of fumarate (0.2 %) and citrate (0.

[Effect of Cu2+ on synthesis of biosurfactants of Acinetobacter calcoaceticus IMV B-7241 and Rhodococcus erythropolis IMV Ac-5017].

Synthesis of biosurfactants (surface-active substances, SAS) was investigated under the conditions of growth of Rhodococcus erythropolis IMV Ac-5017 and Acinetobacter calcoaceticus IMV B-7241 on hydrophobic (n-hexadecane, liquid paraffins, sunflower oil) and hydrophilic (ethanol) substrates depending on concentration (0.01-0.5 mM) and time of copper cations introduction in the medium.

[Production of surfactants by Acinetobacter calcoaceticus K-4 grown on ethanol with organic acids].

The effect of fumarate (C4-dicarboxylic acid, a gluconeogenesis precursor) and citrate (a lipid synthesis regulator) on the production of surfactants by Acinetobacter calcoaceticus K-4 grown on ethanol has been studied. Simultaneous addition of fumarate and citrate to concentrations of 0.01-0.