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1

Glucosyltransferases and glucans of mutans Streptococci as virulence factors in the pathogenesis of dental caries

100%
Wiater A., Szczodrak J.
Biotechnologia
|
2003
|
issue 3
193-206
EN
Mutans streptococci Streptococcus mutans and S. sobrinus play central role in the etiology of human dental caries due to their acidogenic potential and ability to form extracellular water-insoluble and water-soluble glucans in the presence of dietary sucrose. Streptococcal glucans are synthesized by a constitutive group of extracellular and/or cell-associated enzymes showing glucosyltransferase (GTF) activity. Each enzyme has distinctive properties, varying in its requirement for a glucan primer molecule, the proportion of alpha(1-6)- and alpha(1-3)-linkages, the degree of branching it introduces into the glucan, and the total length of glucan chain produced. Moreover, the overall properties of glucan depend on the relative activity of different GTF enzymes, as well as on their interactions, since one GTF may modify the product of another. This review article presents recent trends in the investigations on streptococcal GTFs and glucans. Particular emphasis has been laid on catalytic properties and molecular structure of different GTFs and on the mechanism of synthesis of specific glucans. Furthermore, the role of these enzymes and their products in the pathogenesis of dental caries is also discussed.
2

Production of ethanol from lactose by yeast cells immobilized in open-pore agar

81%
Szczodrak J., Szczodrak Z., Wiater A.
Biotechnologia
|
1997
|
issue 4
82-93
EN
An open-pore agar matrix has been shown to be suitable for the entrapment of Candida pseudotropicalis whole cells are used in reactions that involve cell growth and gas evolution. The basic conditions for lactose fermentation by immobilized yeast cells i.e. inoculum quantity, pH, temperature and culture time were standardized. It was shown that yeast cells immobilized in the porous carrier could be used repeatedly in the batch fermentation system for seven 36 h cycles without any substantial loss in ethanol yield, and beads of porous agar with entrapped cells did not rupture, even after periods of 18 d of use.
3

alpha (13)-Glucan-degrading enzymes. Part I ? Microbial sources, production, properties, genetics

81%
Wiater A., Pleszczynska M., Szczodrak J.
Biotechnologia
|
2006
|
issue 2
206-220
EN
This paper is the first review article concerning the investigations on alpha-(13)-glucans and their enzymatic hydrolysis by specific alpha-(13)-glucanases. Special attention is paid to microbial sources of these enzymes as well as intensification of their production in cultures, their purification and catalytic properties, and molecular structure of the genes encoding different fungal and bacterial alpha-(13)-glucanases.
4

alpha (13)-Glucan-degrading enzymes. Part II ? Application in biotechnology

81%
Wiater A., Pleszczynska M., Szczodrak J.
Biotechnologia
|
2006
|
issue 2
221-233
EN
This paper is focused on actual and potential applications of mutanases as enzymatic dental plaque control agents in vitro and in vivo. All studies reported so far have demonstrated that mutanase was effective in preventing dental caries, suppressing the glucan-dependent adherence and the accumulation of microorganisms in dental plaque, and removing biofilms from dentures. In addition to their potential usefulness in dentistry as oral therapeutic agents, alpha-(13)-glucanases might be applicable to investigations of alpha-(13)-glucosidic linkages occurring in microbial cell-wall structures and glucans of certain higher plants. alpha-(13)-Glucanases obtained in a pure form are invaluable tools for studying the chemical structures of carbohydrates. Most promising prospects for the practical applications of alpha-(13)-glucanases in biocontrol of phytopatogenic fungi, as well as in efficient production of fungal protoplasts, are also discussed.
5

alpha-(1->3)-Glucans from cell wall of Laetiporus sulphureus (Bull.:Fr.) Murrill ? isolation, characteristics and application for induction of mutanase synthesis

81%
Wiater A., Pleszczynska M., Szczodrak J., Prochniak K.
Biotechnologia
|
2008
|
issue 2
174-189
EN
Five different methods described in the literature were used for the isolation of alpha-(1->3)-glucans from the cell wall of fruiting bodies of Laetiporus sulphureus (Bull.:Fr.) Murrill, and their comparative analysis was performed. The separated fungal biopolymers were well-characterized in respect of their structure and some physicochemical properties. Structural analyses, i.e., Fourier-transform infra-red (FT-IR) spectroscopy, 1H nuclear magnetic resonance (NMR) spectroscopy and specific rotation, revealed that the alkali-soluble wall fraction from this basidiomycetous fungus contained about 56% of (1->3)-linked alpha-glucans. Four out of five alpha-(1->3)-glucans isolated by different methods from the mycelium of the polypore fungus L. sulphureus induced higher activity of fungal and bacterial mutanase than those obtained on mutan. Therefore, the alpha-(1->3)-glucans from fruiting bodies of L. sulphureus can be used as a new alternative to streptococcal mutan, which so far has been known as the best inducer of mutanase production
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