ISSN:
1432-0614
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Summary Several strains of the protein-secreting, Gram negative bacterium Myxococcus xanthus were immobilized in carrageenan beads and the production of extracellular proteins was followed. The extracellular proteolytic activity was enhanced and concentrated in the beads. In contrast, the amount of total protein secreted by the cells was not modified by immobilization, but it was also retained and concentrated in the beads, the more, the harder the gel. The amount of slime produced by the cells did not seem to influence protein retention. Foreign proteins expressed from genes cloned in Myxococcus xanthus chromosome can be secreted into the medium by immobilized recombinant strains. A polygalacturonate lyase, expressed from the pelC gene from Erwinia chrysanthemi was only detectable outside of the beads. The pH 2.5 acid phosphatase expressed from the appA gene from Escherichia coli was secreted by immobilized cells at the same rate than did the free cells. It was predominantly found in the medium outside of the beads which represented a first purification and facilitated the continuous production of this protein by immobilized recombinant cells packed in a reactor.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00252008
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