Headspace gas chromatographic determination of beta-galactosidase activity using electron-capture detection.
A headspace gas chromatographic method for the determination of beta-galactosidase (E.C. 3.2.1.23) activity is described. The method, in which 2,2,2-trichloroethyl beta-D-galactopyranoside (beta-TCG) is used as substrate, involves determination of the liberated 2,2,2-trichloroethanol by gas chromatography with electron capture detection. The preparation of beta-TCG and of 2,2,2-trichloroethyl alpha-D-galactopyranoside is described. A Km = 0.80 mM was found for the enzymatic hydrolysis of beta-TCG employing beta-galactosidase from Escherichia coli. The assay has been applied to the quantitative determination of E. coli bacteria.
D002849:Chromatography, Gas; D003069:Coffee / Q000201:enzymology; D004563:Electrochemistry; D004926:Escherichia coli / Q000201:enzymology; D005696:Galactosidases / Q000032:analysis*; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D001616:beta-Galactosidase / Q000032:analysis*
D003069:Coffee; D005696:Galactosidases; D001616:beta-Galactosidase