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Victor J Morris – 1st expert on this subject based on the ideXlab platform
identification cloning and sequencing the acea gene involved in acetan biosynthesis in Acetobacter XylinumFems Microbiology Letters, 1996Co-Authors: Annette Griffin, Victor J Morris, M. J. GassonAbstract:
The aceA gene from Acetobacter Xylinum was identified and cloned from a genomic DNA library. The complete DNA sequence was determined and computer analysis of the translated gene sequence revealed homology with the deduced amino acid sequence of gumD from Xanthomonas campestris. Therefore aceA is likely to encode the phosphate-prenyl glucose I -phosphate transferase catalyzing the first step in acetan biosynthesis in A. Xylinum.
Genetic analysis of the acetan biosynthetic pathway in Acetobacter XylinumInternational Journal of Biological Macromolecules, 1994Co-Authors: Annette M. Griffin, Victor J Morris, M. J. GassonAbstract:
We have identified, cloned and sequenced an 8422 base pair fragment of Acetobacter Xylinum genomic DNA containing part of the acetan biosynthetic gene cluster. Computer analysis of the nucleotide sequence data generated revealed the presence of six open reading frames. Comparison of the translated sequences of putative genes to the amino acid sequences of genes from other organisms was used to assign functions to the aceA, aceC and manB genes. These genes were predicted to encode a UDP-glycosyl transferase, a GDP-mannosyl transferase and a phosphomannose isomerase/GDP-mannose pyrophosphorylase, respectively.
characterization of a variant of the polysaccharide acetan produced by a mutant of Acetobacter Xylinum strain cr1 4Journal of Applied Microbiology, 1993Co-Authors: C A Maccormick, J E Harris, A P Gunning, Victor J MorrisAbstract:
: Acetobacter Xylinum NRRL B42 (NCIB 40123) produces both cellulose and a complex anionic branched heteropolysaccharide called acetan. Chemical mutagenesis was used to isolate stable cellulose-minus Acetobacter Xylinum mutants. Further chemical mutagenesis of these cellulose-minus A. Xylinum bacteria was used to select mutants which secrete polysaccharides which are variants of the acetan structure. Preparation, purification and characterization of these polysaccharides are described. Methylation analysis of the polysaccharide structure CR1/4 suggests that the polysaccharide has an acetan structure with a truncated sidechain terminating in glucuronic acid.
Moshe Benziman – 2nd expert on this subject based on the ideXlab platform
Complementation of cellulose-negative mutants of Acetobacter Xylinum by the cloned structural gene for phosphoglucomutaseFems Microbiology Letters, 2006Co-Authors: Espen Fjærvik, Svein Valla, Kirsten Frydenlund, Yasser Huggirat, Moshe BenzimanAbstract:
Eleven cellulose-negative mutants of Acetobacter Xylinum were analysed with respect to the activities of the enzymes known to be involved in cellulose biosynthesis. The analysis showed that all the mutants were deficient in phosphoglucomutase. All 11 mutants were complemented with a recombinant cosmid from a gene bank of wild type A. Xylinum DNA. A subcloned 3.8-kb DNA fragment from the cosmid insert expressed high levels of phosphoglucumutase in Escherichia coli. Electrophoretic analysis showed that the introduced A. Xylinum activity could be separated from the endogenous phosphoglucomutase present in E. coli. The experiments thus demonstrated that the cloned DNA fragment contained the A. Xylinum structural gene for phosphoglucomutase.
c di gmp binding protein a new factor regulating cellulose synthesis in Acetobacter XylinumFEBS Letters, 1997Co-Authors: Haim Weinhouse, Shai Sapir, D Amikam, Yehudit Shilo, Gail Volman, Patricia Ohana, Moshe BenzimanAbstract:
A protein which specifically binds cyclic diguanylic acid (c-di-GMP), the reversible allosteric activator of the membrane-bound cellulose synthase system of Acetobacter Xylinum, has been identified in membrane preparations of this organism. c-di-GMP binding is of high affinity (KD 20 nM), saturable and reversible. The equilibrium of the reaction is markedly and specifically shifted towards the binding direction by K+. The c-di-GMP binding protein, structurally associated with the cellulose synthase, appears to play a major role in modulating the intracellular concentration of free c-di-GMP and thus may constitute an essential factor in regulating cellulose synthesis in vivo.
V V Klechkovskaya – 3rd expert on this subject based on the ideXlab platform
TEM investigation ofSe nanostructures in/on Acetobacter Xylinum cellulose gel-filmEMC 2008 14th European Microscopy Congress 1–5 September 2008 Aachen Germany, 2020Co-Authors: Natalya A. Arkharova, V V Klechkovskaya, Elena I SuvorovaAbstract:
Acetobacter Xylinum cellulose (A X-BC) and its composites with some mineral and organic additives are the perspective materials for healing the heavy and complicated wounds. The Se/Ag/A X-BC composite is expected to have some antiphlogistic and immunostimulating properties .
network model of Acetobacter Xylinum cellulose intercalated by drug nanoparticlesnamb, 2008Co-Authors: V V Klechkovskaya, Yu G Baklagina, A K Khripunov, V V Volkov, E V Shtykova, Natalia A Arkharova, Ruslan Yu Smyslov, L N Borovikova, A A TkachenkoAbstract:
It was shown that Acetobacter Xylinum cellulose gel-films can sorb silver and selenium nanoparticles stabilized by N-poly(vinyl-2-pirrolidone). The structure of original cellulose matrix, isolated nanoparticles and cellulose with sorbed nanoparticles was characterized by electron diffraction, electron microscopy, small- and wide-angle x-ray scattering methods, and atomic force microscopy. It was found that in static culture Acetobacter Xylinum bacterium (strain VKM B-880) may synthesize high-molecular cellulose with narrow molecular weight distribution and a considerable number of carbon sources. The structures of cellulose microfibrilles and ribbons correspond mainly to polymorphous Iβ modification. We concluded from structural studies that textured cellulose films were formed. The sorption conditions of poly(vinylpyrrolidone)-Se° and poly(vinylpyrrolidone)-Ag° nanoparticles were optimized to obtain a cellulose template that can be used in medical practice.
formation of a composite from se0 nanoparticles stabilized with polyvinylpyrrolidone and Acetobacter Xylinum cellulose gel filmsRussian Journal of Applied Chemistry, 2007Co-Authors: A K Khripunov, V V Klechkovskaya, Yu G Baklagina, A A Tkachenko, L N Borovikova, V K Nilova, Yu R Smyslov, N A Matveeva, Ya A Volkov, V K LavrentevAbstract:
Formation of a composite from Se0 nanoparticles stabilized with polyvinylpyrrolidone and Acetobacter Xylinum cellulose gel films was studied. The optimal sorption parameters at which the amorphous form of the selenium complex is preserved in the composite were suggested.