Linked Life Data

10099524

Source:http://linkedlifedata.com/resource/pubmed/id/10099524

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1999-5-4
pubmed:abstractText
Bacteria displaying heterologous receptors or enzymes on their surface hold great potential as whole-cell adsorbents and biocatalysts, respectively. For industrial applications, such surface-engineered cells need to be killed and chemically fixed to prevent disintegration and leakage of the displayed proteins under process conditions. It is also highly desirable to couple the chemically stabilized cells onto a solid support matrix for additional mechanical stability, flexibility in reactor choice, and easy separation from processed medium. Recently, we described the development of a readily scalable methodology for cell killing, fixation, and outer membrane stabilization via glutaraldehyde fixation followed by secondary crosslinking (Freeman, A., Abramov, S. and Georgiou, G. 1996. Biotechnol. Bioeng. 52: 625-630). Glutaraldehyde treatment was also found, however, to reduce the specific activity of a model enzyme, beta-lactamase displayed on the surface of E. coli. Here, we show that crosslinking carried out in the presence of beta-lactamase inhibitors, namely phenyl boronic acid or sodium borate, protects the active site from chemical modification resulting in up to threefold higher specific activities without affecting the cell-stabilizing effect of the glutaraldehyde treatment. To prepare an immobilized whole cell biocatalyst, residual unreacted surface aldehyde groups were employed to immobilize covalently the fixed bacteria onto chitosan-coated cellulose powder. The binding of the bacteria onto chitosan-coated cellulose was quantitative up to cell loading of 83 mg dry cell weight/g of support. Cell immobilization did not introduce mass transfer limitations and created only a modest reduction in Vmax. Thus, chemical crosslinking, affected in presence of reversible active-site inhibitors and coupled with cell immobilization on chitosan-coated cellulose represents a widely useful methodology for the process application of recombinant bacteria displaying surface-anchored heterologous proteins.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0006-3592
pubmed:author
pubmed:copyrightInfo
Copyright 1999 John Wiley & Sons, Inc.
pubmed:issnType
Print
pubmed:day
20
pubmed:volume
62
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
155-9
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Site-protected fixation and immobilization of Escherichia coli cells displaying surface-anchored beta-lactamase.
pubmed:affiliation
Department of Molecular Microbiology and Biotechnology, Faculty of Life Sciences, Green Building for Biotechnology, Room 222, Tel Aviv University, Tel Aviv 69978, Israel.amihayf@post.tau.ac.il
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't