TITLE

Novel polysaccharide–protein-based amphipathic formulations

AUTHOR(S)
Bach, Horacio; Gutnick, David L.
PUB. DATE
June 2006
SOURCE
Applied Microbiology & Biotechnology;Jun2006, Vol. 71 Issue 1, p34
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Previous results showed that the cell-surface esterase from Acinetobacter venetianus RAG-1 enhances the emulsification properties of the polymeric bioemulsifier emulsan and its deproteinated derivative apoemulsan (Bach H, Berdichevsky Y, Gutnick D (2003) An exocellular protein from the oil-degrading microbe Acinetobacter venetianus RAG-1 enhances the emulsifying activity of the polymeric bioemulsifier emulsan. Appl Environ Microbiol 69:2608–2615). Here we show that in the presence of the his-tagged recombinant esterase from RAG-1, 18 different polysaccharides from microbial, plant, insect and synthetic sources formed hexadecane-in-water emulsions. Emulsifying activities were distributed over a 13-fold range from over 4800 U/mg protein/mg polysaccharide in the case of apoemulsan to 370 U/mg protein/mg polysaccharide in the case of alginic acid. The stability of the emulsions ranged between 95 and 58%. Emulsions formed in the presence of seven of the polysaccharides exhibited stabilities of over 80%. The esterase from A. calcoaceticus BD4, which shows sequence homology to the RAG-1 esterase, was inactive in emulsification enhancement. The sequence of the RAG-1 esterase was shown to contain two conserved peptide sequences previously shown to be implicated in carbohydrate/polysaccharide binding. A hypothetical model illustrating a possible mode of interaction between the esterase, the apoemulsan and the oil droplet is presented. The complex is presumed to generate a series of “coated” oil droplets which are restricted in their ability to coalesce resulting in a relatively stable emulsion.
ACCESSION #
21969214

 

Share

Read the Article

Courtesy of THE LIBRARY OF VIRGINIA

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics