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

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