Selection of biocatalysts for chemical synthesis.
To determine whether microbial chemosensors can be used to find new or better biocatalysts, we constructed Escherichia coli hosts that recognize the product of a biocatalytic conversion through the transcriptional activator NahR and respond by expression of a lacZ or tetA reporter gene. Equipped with a benzaldehyde dehydrogenase (XylC from Pseudomonas putida), the lacZ-based host responded to the oxidation of benzaldehyde and 2-hydroxybenzaldehyde to the corresponding benzoic acids by forming blue colonies, whereas XylC- cells did not. Similarly, the tetA-based host was able to grow under selective conditions only when equipped with XylC, enabling selection of biocatalytically active cells in inactive populations at frequencies as low as 10(-6).
van Sint Fiet
Stephan
S
Institute of Biotechnology, Eidgenössische Technische Hochschule Hönggerberg, HPT Building, Wolfgang-Pauli-Strasse 16, 8093 Zürich, Switzerland.
van Beilen
Jan B
JB
Witholt
Bernard
B
D000445:Aldehyde Oxidoreductases / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D015374:Biosensing Techniques / Q000379:methods*; D002384:Catalysis; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D017930:Genes, Reporter / Q000235:genetics; D005822:Genetic Vectors / Q000235:genetics; D007763:Lac Operon / Q000235:genetics; D016958:Pseudomonas putida / Q000201:enzymology; D013379:Substrate Specificity; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D001616:beta-Galactosidase / Q000235:genetics / Q000378:metabolism
D001426:Bacterial Proteins; C063173:NahR protein, Bacteria; D014157:Transcription Factors; D000445:Aldehyde Oxidoreductases; D001616:beta-Galactosidase