The three genespduCDEencoding the diol dehydratase of Lactobacillus collinoides, have been cloned for overexpres-sion in the pQE30 vector. Although the three subunits of the protein were highly induced, no activity was detected in cell extracts. The enzyme was therefore purified to near homo-geneity by ammoniumsulfate precipitation and gel filtration chromatography. In fractions showing diol dehydratase activity, three main bands were present after SDS/PAGE with molecular masses of 63, 28 and 22 kDa, respectively