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ABSTRACT: The callus culture of duckweed cultivated on medium containing different concentrations of beta-galactosidase was shown to produce the following polysaccharides: pectin lemnan LMC, intracellular AG1, and extracellular AG2 arabinogalactans. The samples of lemnan with 46% galactose residue reduction and 9-46% increased galacturonic acid residue content were obtained at beta-galactosidase concentrations of 10(-3)-10(-1)mg/mL. The most substantial alterations in the sugar composition of pectin were found to occur in the fraction with a molecular mass of 100-300 kDa. Low concentrations of enzyme failed to influence the sugar composition of intracellular arabinogalactan, whereas high concentrations were shown to decrease the amount of arabinose residues in AG1 and to cause galactan formation. Extracellular galactan was found to be produced on the medium with 10(-1) and 1mg/mL beta-galactosidase whereas extracellular arabinogalactan AG2 was shown to be biosynthesized without beta-galactosidase or at a beta-galactosidase concentration of 10(-3)mg/mL. Alterations in the sugar composition of polysaccharides were shown to be connected with the increasing activity of alpha-l-arabinofuranosidase and beta-galactosidase, and with the decreasing activity of intracellular polygalacturonase.
Carbohydrate research 08/2009; 344(18):2602-5. · 2.03 Impact Factor
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ABSTRACT: UV-C irradiation (254 nm) was found to enhance the secretion of some cell-wall-degrading enzymes, especially the following carbohydrases: beta-galactosidase, alpha-L-arabinofuranosidase, polygalacturonase, pectinesterase, cellulase, xylanase, and beta-xylosidase, in the campion callus, contributing thereby to an alteration in the polysaccharide structure. The relative amounts of the galactose and arabinose residues in pectin (silenan) and of arabinose in arabinogalactan of calli irradiated during the exponential phase were shown to decrease during the stationary phase. A decrease in the degree of SV methylesterification was found for the irradiated callus. These alterations were found to persist over a long period of culturing time. Decreasing the relative amounts of the arabinose residues in arabinogalactan and pectin and the galactose residues in silenan corresponded to increasing activity of alpha-L-arabinofuranosidase and beta-galactosidase, respectively, due to treatment with UV-C. UV-C irradiation may be used as a tool for modifying the structural features of the cell-wall polysaccharides, such as the relative amounts of galactose and arabinose residues in the side chains of polysaccharides, with the purpose of obtaining physiologically active polysaccharides with the desired properties and structural features.
Carbohydrate Research 03/2007; 342(2):182-9. · 2.33 Impact Factor
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ABSTRACT: A pectic polysaccharide, lemnan LMC, was extracted from the callus of duckweed Lemna minor L. and was tested for adjuvant properties at oral administration with protein antigen. Mice were orally immunized thrice with weekly interval with free hen's egg lysozyme or lysozyme with LMC. Lemnan LMC was shown to increase delayed type hypersensitivity and serum antilysozyme IgG responses. LMC was established to increase levels of both serum IgG1 and IgG2a subclasses. The concentration of malondialdehyde and myeloperoxidase activity were found to be higher in the tissue samples obtained from small intestine of mice immunized with mixture of lysozyme/LMC than those immunized with lysozyme only. Thus, lemnan appeared to be useful as the adjuvant for oral immunization.
Immunopharmacology and Immunotoxicology 02/2006; 28(1):141-52. · 1.83 Impact Factor
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ABSTRACT: Medium nutrients such as calcium, phosphorus, nitrogen and nitrate to ammonium ratio have significant influence on the growth, biosynthetic and biochemical characteristics of polysaccharides produced by Silene vulgaris (M.) G. cell culture. Cell growth and production of polysaccharides was limited by an absence of any of these components in the medium. Optimal growth of the callus and production of arabinogalactan were achieved at 1.5-4.5 microM calcium while the optimal production of pectin named silenan was observed at 3.0-4.5 microM. The phosphate contents in the medium in the range of 0.63-3.75 microM were favorable for callus growth. Production of silenan was maximal at 1.25-3.75 microM phosphate. Optimal growth of the callus was achieved at 30-90 microM nitrogen. Maximal production of silenan was observed at 60 microM nitrogen while the optimal production of arabinogalactan was at 90 microM nitrogen (at ratio of NH(4)(+):NO(3)(-) as 1:2). A presence both of nitrate and ammonium is needed for the silenan biosynthesis (the NH(4)(+):NO(3)(-) ratio as 1:1 and 1:2). Yields and volumetric production of arabinogalactan were maximal at deletion of ammonium from the nutrient medium (ratio 0:1). Absence of calcium or nitrogen in the medium leads to a decrease of the galacturonic acid residues in silenan. The galactose residues contents in arabinogalactan were decreased in the absence of nitrogen and calcium in the medium.
Journal of Biotechnology 07/2005; 117(4):385-93. · 3.05 Impact Factor
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ABSTRACT: Pectin termed silenan and acidic arabinogalactan were isolated as cell-wall polysaccharides of Silene vulgaris callus in the presence of various carbon sources as components of the media. The maximum yields, productivity per litre of medium and production per day of acidic arabinogalactan, were achieved using glucose or galactose as the carbon source. Sucrose was found to increase the production of the polysaccharides. Yields, productivity and rate of production of arabinogalactan per day were decreased in the presence of arabinose. Yields of silenan, productivity and rate of production per day were closely related irrespective of the sugar used as the carbon source in the media (sucrose, glucose or galactose) and yields of silenan from the callus growing on arabinose were comparable. A concentration of sucrose in the 20-50 g/L range enhanced the biosynthesis of silenan and at 50 g/L the silenan contained the linear backbone and the ramified regions of the macromolecule.
Carbohydrate Research 11/2002; 337(18):1641-5. · 2.33 Impact Factor
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ABSTRACT: In Silene vulgaris (M.) G. cell culture three growth phases were distinguished, namely, a lag phase, an exponential phase and a stationary phase. Pectin termed silenan and an acidic arabinogalactan were isolated as cell wall polysaccharides of S. vulgaris callus at the different growth phases during culture. Production of silenan as the galacturonan (or rhamnogalacturonan) core was observed at the beginning of the exponential phase and at the stationary phase of the callus growth. Arabinogalactan, containing the galacturonic acid residues, is formed at the exponential phase followed by attachment to the core of silenan in the middle of the exponential phase. The arabinogalactan constituent of silenan appeared to be destroyed gradually at the stationary growth phase. The monosaccharide compositions of silenan and arabinogalactan were determined at various phases of the callus growth. Silenan was found to be formed in maximum amounts at the exponential phase of the cell growth. Insignificant alterations of the yields of acidic arabinogalactan were found during culture while total productivity per litre of medium and rate of production per day of arabinogalactan were found to be maximal at the exponential phase of growth.
Phytochemistry 05/2002; 59(7):703-8. · 3.35 Impact Factor
