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Microbial alginate production, modification and its applications.

Hay ID, Ur Rehman Z, Moradali MF, Wang Y, Rehm BH - Microb Biotechnol (2013)

Bottom Line: Alginate is an important polysaccharide used widely in the food, textile, printing and pharmaceutical industries for its viscosifying, and gelling properties.All commercially produced alginates are isolated from farmed brown seaweeds.Here, we will discuss alginates produced by bacteria; the molecular mechanisms involved in their biosynthesis; and the potential to utilize these bacterially produced or modified alginates for high-value applications where defined material properties are required.

View Article: PubMed Central - PubMed

Affiliation: Institute of Fundamental Sciences, Massey University, Private Bag 11222, Palmerston North, New Zealand.

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Modification of bacterial alginate. Showing the acetylation of the first two M residues at C2 and C3 respectively; and the C5 epimerization of the third and forth M residues to G residues. The Ca2+ binding associated with G-blocks is shown. *AlgE1-7 are extracellular epimerases unique to Azotobacter.
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fig03: Modification of bacterial alginate. Showing the acetylation of the first two M residues at C2 and C3 respectively; and the C5 epimerization of the third and forth M residues to G residues. The Ca2+ binding associated with G-blocks is shown. *AlgE1-7 are extracellular epimerases unique to Azotobacter.

Mentions: While the nascent alginate chain is transported across the periplasmic space, it can be modified by O-acetylation and epimerization. Although the order of modification remains unknown, it is conceivable that O-acetylation precedes epimerization, as O-acetylation blocks subsequent epimerization or cleavage (Fig. 3). Although neither O-acetylation nor epimerization are essential for alginate production, they can significantly alter the material properties of the resulting alginate (Donati and Paoletti, 2009). The O-acetylation of alginate is unique to bacterial alginates and significantly increased the water holding capacity of alginate; it is required for efficient biofilm development by Pseudomonads as well as protecting the organism from immune responses (Nivens et al., 2001; Pier et al., 2001).


Microbial alginate production, modification and its applications.

Hay ID, Ur Rehman Z, Moradali MF, Wang Y, Rehm BH - Microb Biotechnol (2013)

Modification of bacterial alginate. Showing the acetylation of the first two M residues at C2 and C3 respectively; and the C5 epimerization of the third and forth M residues to G residues. The Ca2+ binding associated with G-blocks is shown. *AlgE1-7 are extracellular epimerases unique to Azotobacter.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3815931&req=5

fig03: Modification of bacterial alginate. Showing the acetylation of the first two M residues at C2 and C3 respectively; and the C5 epimerization of the third and forth M residues to G residues. The Ca2+ binding associated with G-blocks is shown. *AlgE1-7 are extracellular epimerases unique to Azotobacter.
Mentions: While the nascent alginate chain is transported across the periplasmic space, it can be modified by O-acetylation and epimerization. Although the order of modification remains unknown, it is conceivable that O-acetylation precedes epimerization, as O-acetylation blocks subsequent epimerization or cleavage (Fig. 3). Although neither O-acetylation nor epimerization are essential for alginate production, they can significantly alter the material properties of the resulting alginate (Donati and Paoletti, 2009). The O-acetylation of alginate is unique to bacterial alginates and significantly increased the water holding capacity of alginate; it is required for efficient biofilm development by Pseudomonads as well as protecting the organism from immune responses (Nivens et al., 2001; Pier et al., 2001).

Bottom Line: Alginate is an important polysaccharide used widely in the food, textile, printing and pharmaceutical industries for its viscosifying, and gelling properties.All commercially produced alginates are isolated from farmed brown seaweeds.Here, we will discuss alginates produced by bacteria; the molecular mechanisms involved in their biosynthesis; and the potential to utilize these bacterially produced or modified alginates for high-value applications where defined material properties are required.

View Article: PubMed Central - PubMed

Affiliation: Institute of Fundamental Sciences, Massey University, Private Bag 11222, Palmerston North, New Zealand.

Show MeSH
Related in: MedlinePlus