Biotechnologia Acta

7-16

Authors: E. A. Kiprianova, L. A. Safronova, A. O. Prosyanov

The aim of this review was to present the results of more than ten-year study of gaupsin biopreparation created on the basis of two strains Pseudomonas chlororaphis subsp. aureofaciens UCM В-111 and UCM В-306 with antifungal, entomopathogenic and antiviral activities. Data about antibiotic substances produced by these strains — phenazine and phenylpyrrole derivatives — are presented. Entomocidal properties against the wide spectrum of insect pests have been found out in the strains-producers. Antiviral activity of gaupsin due to the production of thermostable exopolymers containing neutral monosaccharides has been shown using the tobacco mosaic virus as a model. Lipopolysaccharides of the strains В-111 and В-306 also appeared to be highly active antiviral agents. Structure of their O-specific polysaccharides has been established. The last one are structurally heterogenic, presented by linear tri-and tetrasaccharide repeated links and have specific structure that has not been described previously.

26-33

Authors: N. V. Borzova, L. D. Varbanets, V. S. Pidgorskyi, O. D. Ianieva

The aim of the research was to determine the mannan-degrading activity of yeasts cultures isolated from various sources and select strains with high β-mannanase activity. As a result of screening of 245 yeast strains, which are the representatives of 7 genera and 14 species, the active producers of extracellular β-mannanase were identified. To increase β-mannanase activity, the cultures were grown under submerged conditions using guar gum galactomannan as a carbon source and an inducer. β-Mannanase activity was determined by dinitrosalicylic method. The most active biosynthetic species were Cryptococcus albidus, C. gastricus, C. magnus, C. terreus, C. laurentii, Saccharomyces cerevisiae, Williopsis californica, Metschnikowia pulcherrima, Pichia anomala and P. guilliermondii. The activity in culture supernatant was ranged from 0.2 to 75 U/ml. α-Galactosidase activity was found in two strains (Debaryomyces polymorphus UCM Y-152 and Debaryomyces hansenii var. fabryi UCM Y-2400). None of the tested cultures demonstrated both β-mannanase and α-galactosidase activity, that is, they are unable to attack both the main and side chains of galactomannan.

43-51

Authors: S. I. Voychuk

The aim of the study was to evaluate changes in the portion of polar and neutral lipids in the cells of Clostridium during their cultivation in the presence of butanol. Four natural isolates of Clostridium genus were studied with flow cytometry approaches. Under the optimal culture conditions, the polar lipids prevailed over neutral ones in bacterial cells; the content of neutral lipids doubled in spores of these microorganisms, while the content of polar ones was reduced. Strains No 1 and No 2 were able to grow at 1% butanol in the medium, and the strain No 4 was at 1.5%. When cultivated in the presence of different concentrations of butanol, the bacterial strains did not differ in such cytomorphological features as granularity and cell size. The quantitative content of polar and neutral lipids in the presence of butanol varied depending on the content of butanol in the medium, however this effect had a strain-specific character and did not show a correlation with the resistance of these bacteria to butanol. So, the content of polar and neutral lipids varied depending on butanol content in the medium. However this effect was strain-specific independently of resistance of these bacteria to butanol. The use of bacterial biomass as a source of lipids for the production of biofuels requires further optimization of the process to increase the content of the neutral lipid fraction in bacterial cells.

61-67

Authors: A. A. Bilyuk, O. V. Storozhuk, O. V. Kolotiy, H. H. Repich, S. I. Orysyk , L. V. Garmanchuk

The aim of the research was to examine the changes in multi-cellular tumor spheroid growth, adhesion properties and gamma-glutamintranspeptidasic activity in model systems of human breast cancer multicellular spheroid MCF-7 under the influence of Pt(ІІ) and Pd(ІІ) π-complexes with allyl-containing thioureas. Comparing with cisplatin, Pt(II) and Pd(II) complexes reduce gamma-glutamintranspeptidasic activity, increase adhesive properties in model system of solid tumor and inhibit the multicellular spheroids’ growth. All changes prove the importance of further investigation and analysis of these compounds as potential analogues of anticancer drugs that possibly do not cause resistance and reduce the level of metastasis in breast cancer.