Engineering of a stable whole-cell biocatalyst capable of (S)-styrene oxide formation for continuous two-liquid-phase applications

Abstract

Recombinant strains of Pseudomonas putida KT2440 carrying genetic expression cassettes with xylene oxygenase- and styrene monooxygenase- encoding genes on their chromosomes could be induced in shaking-flask experiments to specific activities that rivaled those of multicopy-plasmid- based Escherichia coli recombinants. Such strains maintained the introduced styrene oxidation activity in continuous two-liquid-phase cultures for at least 100 generations, although at a lower level than in the shaking-flask experiments. The data suggest that placement of target genes on the chromosome might be a suitable route for the construction of segregationally stable and highly active whole-cell biocatalysts.