scholarly journals Synthesis and Biological Activity of Acinetobacter calcoaceticus IMV B-7241 Surfactants Depending on Monovalent Cations Content in Cultivation Medium

2021 ◽  
Vol 83 (2) ◽  
pp. 20-31
Author(s):  
T.P. Pirog ◽  
◽  
D.A. Lutsai ◽  
T.A. Shevchuk ◽  
G.O. Iutynska ◽  
...  

Microbial surfactants (biosurfactants) are multifunctional preparations due to a combination of physicochemical (reduction of surface and interfacial tension, emulsifying activity) and biological (antimicrobial and antiadhesive activity, the ability to destroy biofilms) properties. However, the disadvantage of biosurfactants synthesized as a complex of compounds is the possibility of changing the biological activity depending on the conditions of producer cultivation. Aim. To study the effect of potassium and sodium cations on the NADP+-dependent glutamate dehydrogenase activity of cell-free extract of Acinetobacter calcoaceticus ІМV B-7241 with subsequent appropriate modification of the nutrient medium composition and determination of antimicrobial and anti-adhesive activity of surfactant synthesized. Methods. A. calcoaceticus ІМV B-7241 strain was grown in media containing 2% of sunflower oil waste as a carbon source, as well as various concentrations of potassium and sodium chloride (basal – 1.0 g/l NaCl, medium #1 that did not contains NaCl, medium #2 in which the concentration of NaCl was 2.0 g/l, medium #3 in which the concentration of NaCl and KCl was 1.0 g/l each). The surfactants were extracted from the supernatant liquid culture with a modified Folch mixture. Antiadhesive activity and the degree of biofilms degradation were determined by spectrophotometric method, antimicrobial activity − by the indicator of the minimum inhibitory concentration (MIC). Activity of enzymes of surface-active aminolipids biosynthesis (NADP+-dependent glutamate dehydrogenase) and glycolipids (phosphoenolpyruvate (PEP) carboxylase, PEP-synthetase, PEP-carboxykinase, trehalose phosphate synthase) were analyzed in cell-free extracts obtained after the destruction of cells by ultrasound. Results. It was found that potassium and sodium cations in concentrations of 50 and 100 mM are inhibitors of NADP+-dependent glutamate dehydrogenase, and in lower concentrations (5–20 mM) – activators of this enzyme, as well as PEP-carboxykinase and PEP-synthetase. The increase in the biosurfactant concentration to 6.1−7.7 g/l during cultivation of A. calcoaceticus ІМV B-7241 in medium #1 and #3 was due to the predominant synthesis of glycolipids under such conditions, which was evidenced by the increase in 1.8−6.5 times in the activity of PEP-carboxylase, PEP-carboxykinase, PEP-synthetase and trehalose phosphate synthetase compared to the indicators on the basal medium. The concentration of surfactants synthesized in the basal medium was 3.6 g/l, but such surfactants were characterized by the highest antimicrobial and anti-adhesive activity. Their MIC against the test-cultures of studied bacteria (Pseudomonas sp. MI-2, Bacillus subtilis BT-2, Escherichia coli IEM-1, Staphylococcus aureus BMS-1, Enterobacter cloaceae C-8) and fungi (Candida albicans D-6, Rhizopus nigricans P1, Aspergillus niger P-3, Fusarium culmorum T-7) were 0.88−56 μg/ml and were by 2−3 orders of magnitude lower compared to established for surfactants synthesized in modified media #1–3. In the case of treatment of abiotic materials with surfactant solutions obtained on the basal medium, the adhesion of bacteria and fungi was on average 10–20% lower than after surface treatment by the surfactant synthesized in modified media. In the presence of 148−296 μg/ml of surfactants obtained in the basal medium, destruction of S. aureus BMS-1 and B. subtilis BT-2 biofilms was 45−66%, and C. albicans D-6 yeast – 39−44%. Under the action of similar concentrations of surfactants synthesized in modified media, the destruction of bacterial and yeast biofilms was lower: 6-52 and 20–46%, respectively. Conclusions. The obtained results are consistent with the data of our previous studies on the possibility of regulating the antimicrobial and antiadhesive activity of surfactants in the process of producer cultivation by changing the content of cations in the medium, which are inhibitors/activators of enzymes responsible for the synthesis of components of the surfactants complex, which have certain biological properties.

1999 ◽  
Vol 64 (8) ◽  
pp. 1211-1252 ◽  
Author(s):  
Jan Hlaváček ◽  
Renáta Marcová

The first part of this review deals with the biosynthesis and a biological function of strongly vasoactive peptides named endothelins (ETs) including vasoactive intestinal contractor. Where it was useful, snake venoms sarafotoxins which are structural endothelin derivatives, were also mentioned. In the second part, an attention is paid to structural basis of the ETs biological activity, with respect to alterations of amino acid residues in the parent peptides modifying the conformation and consequently the physico-chemical and biological properties in corresponding ETs analogs. Special attention is focussed on the area of ETs receptors and their interaction with peptide and non peptide agonists and antagonists, important in designing selective inhibitors of ETs receptors potentially applicable as drugs in a medicine. A review with 182 references.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Magdalena Woźniak ◽  
Anna Kwiatkowska ◽  
Elżbieta Hołderna-Kędzia ◽  
Katarzyna Sosnowska ◽  
Lucyna Mrówczyńska ◽  
...  

Introduction. Propolis, also known as bee glue, is a resinous material collected by honeybees with numerous biological properties, including antibacterial, antifungal, antioxidant and anticancer effects. Due to its health-promoting properties, propolis is a component of many products, including dietary supplements, cosmetics and healthy food. Aim. The aim of the study was to determine the antibacterial, antifungal and antioxidant activity of propolis extracts, as well as to compare the biological activity of propolis extracts, depending on the solvent used – ethyl alcohol or propylene glycol. Material and methods. Two propolis extracts were used in the research – the first was prepared in ethyl alcohol, and the second in propylene glycol. The antimicrobial activity of the examined extracts was determined against S. aureus, E. coli and C. albicans. The antioxidant activity was determined on the basis of the evaluation of their antiradical activity in the DPPH· test and Fe2+ chelating activity. Moreover, the total content of phenolic compounds and flavonoids in the tested extracts was determined using the colorimetric method. Results. The tested propolis extracts, regardless of the solvent used (ethyl alcohol or propylene glycol), showed high antibacterial (against S. aureus), antifungal (against C. albicans) and antioxidant (antiradical activity in the DPPH· test and ferrous iron chelating potency in the ferrozine test) activity. Moreover, both tested extracts were characterized by a high and similar content of bioactive compounds – phenolic compounds and flavonoids. Conclusions. The results of the conducted tests showed that the solvent used did not affect determined biological activity and the content of bioactive substances in the tested propolis extracts.


2021 ◽  
Author(s):  
Yuliya Akimenko

Abstract In model laboratory and field conditions, the influence of pollution by antibiotics (benzylpenicillin, ampicillin, streptomycin, oxytetracycline, tylosin, pharmasin, tromexin, aliseryl, and nystatin) on the biological properties of ordinary chernozem was examined in concentrations of 1-1000 mg/kg. A decrease in the majority of the basic biological parameters of chernozem occurs when the concentration of antibiotics is 100 mg/kg of soil. In most cases, there was a direct relationship between the content of antibiotics in the soil and the scale of a decrease in the studied parameters. The degree of the influence of antibiotics was determined by their nature, concentration and time of exposure. Antibacterial antibiotics had more negative impact on the studied indicators than fungicidal ones. By the degree of inhibiting the biological properties of chernozem, antibiotics formed the following sequence: ampicillin > benzylpenicillin ≥ streptomycin ≥ oxytetracycline > tylosin ≥ pharmasin > nystatin > tromexin > aliseryl. Among the examined biological parameters when polluted by antibiotics, the most informative one was the number of ammonifying bacteria and the activity of dehydrogenases. The least informative was the indicator of catalase activity. The abundance of bacteria of the genus Azotobacter in case of pollution by antibiotics was not informative. The degree of a decrease in biological indicators was more pronounced in laboratory conditions than in the field ones. The rate of the biological activity recovery of chernozem after pollution in the field was 2 times higher. According to the degree of resistance to antibiotics, the investigated microorganisms of chernozem formed the following sequence: bacteria of the genus Azotobacter > micromycetes > amylolytic bacteria > ammonifying bacteria. Enzymes formed the following sequence: peroxidase ≥ polyphenol oxidase > catalase > dehydrogenase > invertase ≥ phosphatase. Antibiotics had prolonged influence on the biological properties of ordinary chernozem. The examined parameters were observed not to be recovered to control values even on the 120th day after the pollution.


1988 ◽  
Vol 8 (7) ◽  
pp. 2933-2941
Author(s):  
P Delli-Bovi ◽  
A M Curatola ◽  
K M Newman ◽  
Y Sato ◽  
D Moscatelli ◽  
...  

We recently reported that the protein encoded in a novel human oncogene isolated from Kaposi sarcoma DNA was a growth factor with significant homology to basic and acidic fibroblast growth factors (FGFs). To study the properties of this growth factor (referred to as K-FGF) and the mechanism by which the K-fgf oncogene transforms cells, we have studied the production and processing of K-FGF in COS-1 cells transfected with a plasmid encoding the K-fgf cDNA. The results show that, unlike basic and acidic FGFs, the K-FGF protein is cleaved after a signal peptide, glycosylated, and efficiently secreted as a mature protein of 176 or 175 amino acids. Inhibition of glycosylation impaired secretion, and the stability of the secreted K-FGF was greatly enhanced by the presence of heparin in the cultured medium. We have used the conditioned medium from transfected COS-1 cells to test K-FGF biological activity. Similar to basic FGF, the K-FGF protein was mitogenic for fibroblasts and endothelial cells and induced the growth of NIH 3T3 mouse cells in serum-free medium. Accordingly, K-fgf-transformed NIH 3T3 cells grew in serum-free medium, consistent with an autocrine mechanism of growth. We have also expressed the protein encoded in the K-fgf protooncogene in COS-1 cells, and it was indistinguishable in its molecular weight, glycosylation, secretion, and biological activity from K-FGF. Taken together, these results suggest that the mechanism of activation of this oncogene is due to overexpression rather than to mutations in the coding sequences.


2008 ◽  
Vol 3 (10) ◽  
pp. 1934578X0800301 ◽  
Author(s):  
Maria I. Bilan ◽  
Anatolii I. Usov

Sulfated polysaccharides of brown algae (“fucoidans”) constitute a wide variety of biopolymers from simple sulfated fucans up to complex heteropolysaccharides composed of several neutral monosaccharides, uronic acid and sulfate. The increased interest in this class of polysaccharides is explained by their high and versatile biological activities, and hence, by their possible use in new drug design. Structural analysis of several fucoidans demonstrates that their biological properties are determined not only by charge density, but also by fine chemical structure, although distinct correlations between structure and biological activity cannot be formulated at present. The aim of this review is to describe the methods of structural analysis currently used in fucoidan chemistry, and to discuss some new information on the structures of fucoidans presented in recent publications.


2018 ◽  
Vol 42 (6) ◽  
pp. 4679-4692 ◽  
Author(s):  
Ahmet Karadağ ◽  
Nesrin Korkmaz ◽  
Ali Aydın ◽  
Şaban Tekin ◽  
Yusuf Yanar ◽  
...  

The synthesis, characterization and biological activity of three novel dicyanidoargentate(i)-based complexes are reported. The in vitro results show that these complexes may be potent antiproliferative drug candidates.


1986 ◽  
Vol 13 (3) ◽  
pp. 399 ◽  
Author(s):  
PW Hattersley ◽  
NE Stone

The activities of eight key photosynthetic enzymes were measured in leaf blade extracts of the C3-C4 intermediate Neurachne minor S. T. Blake, its C3 and C4 relatives, C3-C4 Panicum milioides Nees ex Trin., and controls (all Poaceae). Phosphoenolpyruvate (PEP) carboxylase (PEPC) activity in N. minor (5.46 �mol mg Chl-1 min-1) is higher than previously reported for any other C3-C3 plant, and the ratio of ribulose-1,5-bisphosphate carboxylase activity to PEPC activity is lower than for P. milioides or C3 species. Activity of pyruvate,PI dikinase (up to 0.88 �mol mg Chl-1 min-1) is 3-5 times higher than in P. milioides. Assays of NADP-malic enzyme (NADP-ME), NAD-malic enzyme (NAD-ME) and PEP carboxykinase (PCK) show Paraneurachne muelleri (Hack.) S. T. Blake and Neurachne munroi (F. Muell.) F. Muell., N. minor's two close C4 relatives, to be NADP-ME type, as predicted from leaf anatomy. Aspartate and alanine aminotransferase activities in these species are higher than expected, however. N. minor (C3-C4) exhibits higher C4 acid decarboxylase activity than C3 species or P. milioides, for NADP-ME only (up to 1.07 �mol mg Chl-1 min-1). Our results suggest that N. minor possesses a limited C4 acid cycle, and that it is the most C4-like C3-C4 intermediate grass currently identified, comparable with some of the known C3-C4 Flaveria (Asteraceae) species.


Author(s):  
A.V. SYROESHKIN ◽  
E.V. USPENSKAYA ◽  
T.V. PLETENEVA ◽  
M.A. MOROZOVA ◽  
T.V. MAKSIMOVA ◽  
...  

Objective: Study the influence of the mechanical preparation methods (grinding, fluidization) of solid pharmaceutical substances (PS) and herbal raw material on their physicochemical properties and biological activities. Methods: Test substances and solvents-Lactose monohydrate (DFE Pharma, Germany). Sodium chloride, bendazol hydrochloride (all Sigma-Aldrich, USA) and herbal raw material (Callisia fragrans). The dispersity and native structure of pharmaceutical substances were analyzed by several methods: optical microscopy–Altami BIO 2 microscope (Russia); low angle laser light scattering (LALLS) method (Malvern Instruments, UK); Spirotox method–Quasichemical kinetic of cell transition of cellular biosensor Spirostomum ambiguum; Fourier-transform infrared spectroscopy–the analysis in the middle IR region was carried out using an IR Cary 630 Fourier spectrometer (Agilent Technologies, USA). The analysis of dried leaves of C. fragrans before and after mechanical activation was performed using Shimadzu EDX-7000 X-ray fluorescence spectrophotometer without mineralization (Shimadzu, Japan). Results: It was established that the mechanical change, such as dispersion and drying, alters the biological activity of PS and herbal raw materials. The observed increase in the influence of the dispersed substance on the biosensor S. ambiguum is quantitatively estimated from the values of the activation energy (obsEa), which turns to be valued 1,5 (P≤0,05) times more than for the native form substance. In the study of the dependence of the availability of chemical elements K, Ca, Zn on the degree of dispersion of herbal raw materials was established a quantitative 4-fold (P≤0,05) increase in the concentration of elements in mechano-activated raw materials. Conclusion: By the example of the biological model of Spirotox (single-celled biosensor S. ambiguum) and herbal raw materials obtained from C. fragrans, the increase of biological activity of PS at the dispersion of initial preparations was proved.


Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1776 ◽  
Author(s):  
Massimiliano Magro ◽  
Davide Baratella ◽  
Andrea Venerando ◽  
Giulia Nalotto ◽  
Caroline R. Basso ◽  
...  

Generally, enzyme immobilization on nanoparticles leads to nano-conjugates presenting partially preserved, or even absent, biological properties. Notwithstanding, recent research demonstrated that the coupling to nanomaterials can improve the activity of immobilized enzymes. Herein, xanthine oxidase (XO) was immobilized by self-assembly on peculiar naked iron oxide nanoparticles (surface active maghemite nanoparticles, SAMNs). The catalytic activity of the nanostructured conjugate (SAMN@XO) was assessed by optical spectroscopy and compared to the parent enzyme. SAMN@XO revealed improved catalytic features with respect to the parent enzyme and was applied for the electrochemical studies of xanthine. The present example supports the nascent knowledge concerning protein conjugation to nanoparticle as a means for the modulation of biological activity.


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