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Large-scale production and homogenous purification of long chain polysialic acids from E. coli K1

Paper ID Volume ID Publish Year Pages File Format Full-Text
24829 43539 2008 8 PDF Available
Title
Large-scale production and homogenous purification of long chain polysialic acids from E. coli K1
Abstract

The study of new biomaterials is the objective of many current research projects in biotechnological medicine. A promising scaffold material for the application in tissue engineering or other biomedical applications is polysialic acid (polySia), a homopolymer of α2,8-linked sialic acid residues, which represents a posttranslational modification of the neural cell adhesion molecule and occurs in all vertebrate species. Some neuroinvasive bacteria like, e.g. Escherichia coli K1 (E. coli K1) use polySia as capsular polysaccharide. In this latter case long polySia chains with a degree of polymerization of >200 are linked to lipid anchors. Since in vertebrates no polySia degrading enzymes exist, the molecule has a long half-life in the organism, but degradation can be induced by the use of endosialidases, bacteriophage-derived enzymes with pronounced specificity for polySia.In this work a biotechnological process for the production of bacterial polysialic acid is presented. The process includes the development of a multiple fed-batch cultivation of the E. coli K1 strain and a complete downstream strategy of polySia. A controlled feed of substrate at low concentrations resulted in an increase of the carbon yield (Cproduct/Csubstrate) from 2.2 to 6.6%. The downstream process was optimized towards purification of long polySia chains. Using a series of adjusted precipitation steps an almost complete depletion of contaminating proteins was achieved. The whole process yielded 1–2 g polySia from a 10-l bacterial culture with a purity of 95–99%. Further product analysis demonstrated maximum chain length of >130 for the final product.

Keywords
a.c., acetate; b.l.d., below limit of detection; BPB, bromphenol blue; BCP, bromcresol purple; CA, colominic acid; cetavlon, cetyltrimethyl ammonium bromide; DMB, 1,2-diamino-4,5-methylenedioxybenzene; DO, dissolved oxygen; DP, degree of polymerization; E
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Large-scale production and homogenous purification of long chain polysialic acids from E. coli K1
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Publisher
Database: Elsevier - ScienceDirect
Journal: Journal of Biotechnology - Volume 135, Issue 2, 1 June 2008, Pages 202–209
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us