Expression of Recombinant alpha-Acetolactate Decarboxylase and Its Characterization

alpha-Acetolactate decarboxylase(alpha-ALDC)gene has been cloned from Baillus brevis using PCR amplification. The amplified 0.97 kb DNA fragment was confirmed to be known alpha- ALDC gene by DNA sequencing. The fragment was inserted into the vector pBV220 to construct an expression plasmid pBVYI. This recombinant plasmid over expressed alpha-ALDC in E. coli DH5alpha. The alpha-ALDC activity of recombinant bacterium was 10 000-fold higher than that of Bacillus brevis. After purification, the properties of the recombinant alpha-ALDC were studied. The activity of this enzyme could be stimulated by Mn(2+), Sn(2+) and inhibited by Zn(2+), Cd(2+), Fe(2+), Co(2+) and Cu(2+). Moreover, amino acid modifiers could inhibit differently its activity. The optimum pH of the enzyme reaction was 5.5.