Enzymes from Pseudomonas sp. strain NCIB 11097 participating in biotransformation of acetaldehyde and glycine to threonine isomers

Enzyme activities involved in L-threonine bioconversions present in cells of Pseudomonas sp. strain NCIB 11097 were separated by phenyl-Sepharose hydrophobic chromatography. The separation of the two main activity components was monitored by discontinuous polyacrylamide gel electrophoresis. Threonine aldolase catalyzed the conversion of glycine and acetaldehyde to a mixture of isomers, L-threonine and L-allothreonine, in a biotransformation reaction having pH and temperature optima of 7.5 and 25-30 degrees C, respectively. The fraction containing serine hydroxymethyltransferase converted acetaldehyde and glycine specifically to L-allothreonine in a biotransformation reaction having pH and temperature optima of 7.4 and 37 degrees C, respectively.