Fulltext

Expression of PHA polymerase genes of Pseudomonas putida in Escherichia coli and its effect on PHA formation

Ren, Qun ; Beilen, Jan ; Sierro, Nicolas ; Zinn, Manfred ; Kessler, Birgit ; Witholt, Bernard

In: Antonie van Leeuwenhoek, 2005, vol. 87, no. 2, p. 91-100

Ajouter à la liste personnelle
    Titre
    • Expression of PHA polymerase genes of Pseudomonas putida in Escherichia coli and its effect on PHA formation
    Auteur
    • Ren, Qun. Biocompatible Materials, Swiss Federal Laboratories for Materials Testing and Research (EMPA), Lerchenfeldstrasse 5, 9014 St., Gallen, Switzerland
    • Beilen, Jan. Institute of Biotechnology, Swiss Federal Institute of Technology, CH-8093, Zurich, Switzerland
    • Sierro, Nicolas. Institute of Biotechnology, Swiss Federal Institute of Technology, CH-8093, Zurich, Switzerland
    • Zinn, Manfred. Biocompatible Materials, Swiss Federal Laboratories for Materials Testing and Research (EMPA), Lerchenfeldstrasse 5, 9014 St., Gallen, Switzerland
    • Kessler, Birgit. Prädialstab, Swiss Federal Institute of Technology, HG F 52.2, CH-8092, Zurich, Switzerland
    • Witholt, Bernard. Institute of Biotechnology, Swiss Federal Institute of Technology, CH-8093, Zurich, Switzerland
    Type de document
    • Postprint
    Langue
    • Anglais
    Publié dans
    • Antonie van Leeuwenhoek, 2005, vol. 87, no. 2, p. 91-100. Kluwer Academic Publishers
    Autre version électronique
    Identifiant OAI-PMH
    • oai:doc.rero.ch:322371
    Summary
    Poly-3-hydroxyalkanoates (PHAs) are synthesized by many bacteria as intracellular storage material. The final step in PHA biosynthesis is catalyzed by two PHA polymerases (phaC) in Pseudomonas putida. The expression of these two phaC genes (phaC1 and phaC2)was studied in Escherichia coli, either under control of the native promoter or under control of an external promoter. It was found that the two phaC genes are not expressed in E. coli without an external promoter. During heterologous expression of phaC from Plac on a high copy number plasmid, a rapid reduction of the number of colony forming units was observed, especially for phaC2. It appears that the plasmid instability was partially caused by high-level production of PHA polymerase. Subsequently, tightly regulated phaC2 expression systems on a low copy number vector were applied in E. coli. This resulted in PHA yields of over 20 of total cell dry weight, which was 2 fold higher than that obtained from the system where phaC2 is present on a high copy number vector. In addition, the PHA monomer composition differed when different gene expression systems or different phaC genes were applied