IGEM:IMPERIAL/2009/Encapsulation/Phase2/Alginate Biosynthesis/Bacteria2

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Properties of bacteria

A.vinelandii is non-pathogenic soil bacterium

In its lifecycle, forms a spherical dormant cyst with alginate being important component. The cyst is protective against dessication and environment.

The complete sequence of A. vinelandii genome has recently been sequenced. [1]

Metabolic engineering is currently underway to increase alginate production. [2]


Image:a genes.jpg

Image:a pathway.jpg

basically similar to P.aeruginosa

Main difference is the presence of a larger number of epimerase genes.

Epimerase genes

seven homologous secreted mannuronan C-5 extracellular epimerases AlgE1-7

secreted by bacteria into extracellular environment and acts on polymannuronate

each epimerase produces introduce G with varying patterns

  • AlgE2 introduces G-blocks (gel-forming alginate).
  • AlgE1 and E6 are also G-block forming enzymes.
  • AlgE4 produces alternating MG blocks

the properties of the AlgE epimerases have been extensively studied in vitro after recombinant expression in Escherichia coli[3]

the AlgE epimerase has been cloned into E.coli to produce epimerase. The epimerase was purified and mixed with alginate to improve the G-block quality of alginate. [4]

transport of epimerase

In silico identification of Type I secretion machineries eexD-F required to transport AlgE epimerase out of cell[4]

Image:algE tpt gene.jpg

inactivation of the genes (eexD–F) encoding a particular Type 1 protein transport system leads to blocked AlgE transport[3]

Useful Papers

Error fetching PMID 17306024:
  1. Error fetching PMID 17306024: [Alginate1]
Error fetching PMID 18373676:
  1. Error fetching PMID 18373676: [Alginate2]
Error fetching PMID 8188585:
  1. Error fetching PMID 8188585: [Alginate3]
Error fetching PMID 16855245:
  1. Error fetching PMID 16855245: [Alginate4]
Error fetching PMID 19429624:
  1. Error fetching PMID 19429624: [Alginate5]
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