A comparison of the effect of fucoidan from alga Fucus vesiculosus and its fractions obtained by anion-exchange chromatography on HeLa G-63, Hep G2, and Chang liver cells

The aim of this study was to compare the effects of sulfated fucopolysaccharides isolated from Fucus vesiculosus on HeLa G-63, Hep G2, and Chang liver cells. Native fucoidan F3 and two fractions (F3-0.5 and F3-1) obtained by anion-exchange chromatography were analyzed using chemical methods and IR spectroscopy. It was demonstrated that F3 and F3-1 are characterized by a higher content of sulfates, location of sulfo groups mostly at the C4 atom of fucose residue, and low content of uronic acids inhibited cell proliferation. Human liver carcinoma Hep G2 appeared to be the most sensitive to fucoidan, whereas nonmalignant human Chang liver cells were the least sensitive

Whole-Cell PVA Cryogel-Immobilized Microbial Consortium LE-C1 for Xanthan Depolymerization

Xanthan is an extracellular heteropolysaccharide produced by the bacteria Xanthomonas campestris. Due to its unique properties, the polysaccharide and its derivatives are widely used in many industries, from food to biomedicine and oil production, that demands an efficient xanthan depolymerization method to adapt this polysaccharide for various applications. Unlike the known chemical approaches, biological methods are considered to be more environmentally friendly and less energy intensive. In laboratory conditions, we have isolated a bacterial community capable of reducing the xanthan viscosity. Identification of the individual isolates in the microbial community and their testing resulted in the consortium LE-C1, consisting of two microorganisms Paenibacillus phytohabitans KG5 and Cellulosimicrobium cellulans KG3. The specific activities of the overall xanthanase and auxiliary enzymes that may be involved in the xanthan depolymerization were as follows: xanthanase, 19.6 ± 0.6 U/g; β-glucosidase, 3.4 ± 0.1 U/g; α-mannosidase, 68.0 ± 2.0 U/g; β-mannosidase, 0.40 ± 0.01 U/g; endo-glucanase, 4.0 ± 0.1 U/g; and xanthan lyase, 2.20 ± 0.07 U/mg. In order to increase the efficiency of xanthan biodegradation, the LE-C1 whole cells were immobilized in a poly(vinyl alcohol) cryogel. The resulting regenerative biocatalyst was able to complete xanthan depolymerization within 40 cycles without loss of activity or degradation of the matrix

Комбинация низких доз глюкозамина и 2-DG усиливает цитотоксический эффект в опухолевых клетках человека в культуре

Chemotherapy for tumors has traditionally been aimed at inhibiting proliferation and activating apoptosis of cancer cells. Aim. To perform a comparative study of effects of two glucose analogues, 2-deoxy-D-glucose (2-DG) and glucosamine D, at low concentrations (1.5-10 mM) on carcinoma cells (HeLaG63 line) and endotheliocytes (ECV304 line). Methods. Efficacy of these agents was evaluated by decreased cell viability (MTT test), permeability of the cell membrane, changes in progression by the cell cycle, and apoptosis (cytometric method) of cells cultured in mediums with different glucose concentrations. Results. The 48-h 2-DG treatment of cells in the studied concentrations reduced the proportion of cells in G1 and S-phases and their accumulation in G2\M phases. The same concentrations of glucosamine D, as distinct from 2-D, blocked the same cells in the G1\S phase of the cell cycle. The same concentrations of glucosamine D were more toxic to carcinoma cells than 2-DG. A combination of 2-DG and glucosamine D significantly greater increased the sub-G1 population of HeLaG63 cells than either agent alone. The treatment effectiveness increased with a decrease in the glucose concentration in the medium and/or with an increase in the agent dose. Endotheliocytes (ECV304) were less sensitive to both glucosamine D and 2-DG, and the effect of their combination did not differ from the effect of either agent alone, even at concentrations of 10 mM. Treatment of cells with 10 mM 2-DG and glucosamine D increased the cell membrane permeability for the fluorescent dye, propidium iodide, with the greatest effect recorded for HeLaG63 cells. Conclusion. Therefore, the anticarcinogenic efficacy of glycolysis inhibitors can be enhanced, which would allow to considerably reduce their doses and avoid potential side effects induced by therapeutically effective drug concentrations.Химиотерапия опухолей традиционно направлена на ингибирование пролиферации раковых клеток и активацию апоптоза. В данной работе на клетках карциномы (линия HeLaG63) и эндотелиоцитах (линия ECV304) человека проведено сравнительное исследование эффектов низких концентраций (1,5-10мМ) двух аналогов глюкозы: 2-DG и глюкозамина D. Оценка эффективности действия этих агентов проводилась по следующим параметрам: снижение жизнеспособности по МТТ-тесту, изменение проницаемости клеточной мембраны, изменение прогрессии по клеточному циклу, выраженность апоптотической гибели при культивировании клеток в питательной среде с различным содержанием глюкозы. Показано, что 48 часовая обработка 2-DG в исследованных концентрациях приводила к снижению доли клеток в G1 и S-фазах и аккумуляции их в G2\M фазах. Глюкозамин D, в отличие от 2-DG при тех же концентрациях блокировал эти же клетки в G1\S фазе клеточного цикла. При обработке клеток HeLaG63 глюкозамин D оказывал более токсичное действие, чем 2-DG. При сочетанном воздействии 2-DG и глюкозамина D регистрировали существенное увеличение суб- G1-популяции по сравнению с раздельным воздействием. Эффективность обработки увеличивалась при снижении концентрации глюкозы в питательной среде и/или с увеличением дозы агентов. Эндотелиоциты (ECV304) были менее чувствительны, как к действию глюкозамина D, так и 2-DG, и сочетанное воздействие даже при концентрациях 10мМ не отличалось от раздельного воздействия. Обработка клеток 10мМ 2-DG и глюкозамина D приводила к увеличению проницаемости клеточных мембран для флуоресцентного красителя пропидиум йодида, при этом наибольшую эффективность регистрировали для клеток HeLaG63

Antibacterial Properties of Fucoidans from the Brown Algae <i>Fucus vesiculosus</i> L. of the Barents Sea

Fucoidans, sulfated polysaccharides found in cell walls of brown algae, are considered as a promising antimicrobial component for various applications in medicine and the food industry. In this study, we compare the antibacterial properties of two fractions of fucoidan from the brown algae Fucus vesiculosus gathered in the littoral of the Barents Sea and sampled at different stages of purification. The crude fraction of fucoidan was isolated from algae by extraction with aqueous ethanol and sonication. The purified fraction was obtained by additional treatment of the crude fraction with a solution of calcium chloride. The structural features of both fractions were characterized in detail and their antibacterial effects against several Gram-positive and Gram-negative bacteria were compared by photometry, acridine orange staining assay, and atomic force microscopy. Fucoidan inhibited growth in all of the above microorganisms, showing a bacteriostatic effect with minimum inhibitory concentrations (MIC) in the range between 4 and 6 mg/mL, with E. coli being the most sensitive to both fractions. Changes in the chemical composition after treatment of the crude fraction with a solution of calcium chloride led to a decrease in the content of sulfates and uronic acids and diminished antibacterial activity

Calcifying Bacteria Flexibility in Induction of CaCO3 Mineralization

Microbially induced CaCO3 precipitation (MICP) is considered as an alternative green technology for cement self-healing and a basis for the development of new biomaterials. However, some issues about the role of bacteria in the induction of biogenic CaCO3 crystal nucleation, growth and aggregation are still debatable. Our aims were to screen for ureolytic calcifying microorganisms and analyze their MICP abilities during their growth in urea-supplemented and urea-deficient media. Nine candidates showed a high level of urease specific activity, and a sharp increase in the urea-containing medium pH resulted in efficient CaCO3 biomineralization. In the urea-deficient medium, all ureolytic bacteria also induced CaCO3 precipitation although at lower pH values. Five strains (B. licheniformis DSMZ 8782, B. cereus 4b, S. epidermidis 4a, M. luteus BS52, M. luteus 6) were found to completely repair micro-cracks in the cement samples. Detailed studies of the most promising strain B. licheniformis DSMZ 8782 revealed a slower rate of the polymorph transformation in the urea-deficient medium than in urea-containing one. We suppose that a ureolytic microorganism retains its ability to induce CaCO3 biomineralization regardless the origin of carbonate ions in a cell environment by switching between mechanisms of urea-degradation and metabolism of calcium organic salts

Effect of Brown Algae and Lichen Extracts on the SCOBY Microbiome and Kombucha Properties

Kombucha tea was made by the fermentation of SCOBY culture of green tea broth with the addition of Fucus vesiculosus algae extract, Cetraria islandica lichen extract and their mixture. Kombucha was also made without the herbal supplements as a control. After 11 days of fermentation, in addition to the yeast Brettanomyces bruxellensis and the bacteria Komagataeibacter rhaeticus and Komagataeibacter hansenii contained in all of the samples, the yeast Zygosaccharomyces bailii and bacteria Komagataeibacter cocois were detected in the samples with the herbal extracts. In all of the kombucha with herbal additives, the total fraction of yeast was decreased as compared to the control. The total content of polyphenols and the antioxidant activity of the beverages with and without the addition of herbal extracts were comparable. The kombucha made with the algae extract showed an increased content of sucrose and organic acids, while the fructose and glucose content in the samples with algae and the mixture of extracts were lower than in the other samples. The samples with the algae extract had the highest organoleptic indicators “aroma”, “clarity” and “acidity”, while the control samples had slightly higher indicators of “taste” and “aftertaste”. The results of this study indicate the potential of algae and lichens as functional supplements for obtaining non-alcoholic fermented beverages with additional nutraceutical value