Limits...
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.

Show MeSH

Related in: MedlinePlus

Schematic representation of the alginate polymerization/secretion complex spanning from the inner membrane to the outer membrane. Acetylation by AlgI, AlgJ, AlgF and AlgX and epimerization by AlgG are demonstrated by dashed lines. It remains unclear whether AlgJ or AlgX or both are responsible for the direct acetylation of the alginate chain. Deduced interactions are shown as triangles, with white triangles indicating a mutual stability relationship and black triangles representing a direct interaction as indicated by pull down data.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3815931&req=5

fig04: Schematic representation of the alginate polymerization/secretion complex spanning from the inner membrane to the outer membrane. Acetylation by AlgI, AlgJ, AlgF and AlgX and epimerization by AlgG are demonstrated by dashed lines. It remains unclear whether AlgJ or AlgX or both are responsible for the direct acetylation of the alginate chain. Deduced interactions are shown as triangles, with white triangles indicating a mutual stability relationship and black triangles representing a direct interaction as indicated by pull down data.

Mentions: As mentioned above, it has long been suggested that the members of the alginate biosynthesis machinery form a multiprotein complex spanning from the IM, through the periplasmic space and into the outer membrane. Several studies have elucidated the specific protein–protein interactions involved in this complex (Gutsche et al., 2006; Keiski et al., 2010; Hay et al., 2012; Rehman and Rehm, 2013; Rehman et al., 2013). Recently, Rehman and colleagues (2013) have undertaken a series of pull-down, cross-linking and mutual-stability experiments in an effort to map the specific protein–protein interactions in the multiprotein complex. This has led to a model for the alginate polymerization/secretion complex as depicted in Fig. 4 (with experimentally deduced interactions indicated by triangles). Intriguingly, a key regulatory protein, MucD, appears to interact with the complex through AlgX. It is unclear what the function of this interaction is, but it has been suggested that MucD may be sequestered by an intact complex and becomes free to exert its regulatory role if the complex becomes instable (Gutsche et al., 2006; Hay et al., 2012).


Microbial alginate production, modification and its applications.

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

Schematic representation of the alginate polymerization/secretion complex spanning from the inner membrane to the outer membrane. Acetylation by AlgI, AlgJ, AlgF and AlgX and epimerization by AlgG are demonstrated by dashed lines. It remains unclear whether AlgJ or AlgX or both are responsible for the direct acetylation of the alginate chain. Deduced interactions are shown as triangles, with white triangles indicating a mutual stability relationship and black triangles representing a direct interaction as indicated by pull down data.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig04: Schematic representation of the alginate polymerization/secretion complex spanning from the inner membrane to the outer membrane. Acetylation by AlgI, AlgJ, AlgF and AlgX and epimerization by AlgG are demonstrated by dashed lines. It remains unclear whether AlgJ or AlgX or both are responsible for the direct acetylation of the alginate chain. Deduced interactions are shown as triangles, with white triangles indicating a mutual stability relationship and black triangles representing a direct interaction as indicated by pull down data.
Mentions: As mentioned above, it has long been suggested that the members of the alginate biosynthesis machinery form a multiprotein complex spanning from the IM, through the periplasmic space and into the outer membrane. Several studies have elucidated the specific protein–protein interactions involved in this complex (Gutsche et al., 2006; Keiski et al., 2010; Hay et al., 2012; Rehman and Rehm, 2013; Rehman et al., 2013). Recently, Rehman and colleagues (2013) have undertaken a series of pull-down, cross-linking and mutual-stability experiments in an effort to map the specific protein–protein interactions in the multiprotein complex. This has led to a model for the alginate polymerization/secretion complex as depicted in Fig. 4 (with experimentally deduced interactions indicated by triangles). Intriguingly, a key regulatory protein, MucD, appears to interact with the complex through AlgX. It is unclear what the function of this interaction is, but it has been suggested that MucD may be sequestered by an intact complex and becomes free to exert its regulatory role if the complex becomes instable (Gutsche et al., 2006; Hay et al., 2012).

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