Primers and a specific DNA probe for detecting lactic acid bacteria producing 3-hydroxypropionaldehyde from glycerol in spoiled ciders

Of the 40 strains isolated from several spoiled ciders where glycerol was d egraded, 36 were identified as Lactobacillus collinoides, three were Lactob acillus hilgardii, and one was Lactobacillus mali. However, only 30 L. coll inoides and two L. hilgardii could degrade glycerol. The glycerol dehydrata se activity was shown. The main product of the transformation was 1,3 propa nediol. Two DNA primers GD1 and GD2 were chosen in the region encoding one of the subunits of glycerol dehydratase of Citrobacter freundii, Klebsiella pneumoniae, Klebsiella oxytoca, Salmonella Typhimurium, and Clostridium pa stertrianum. A 279-bp amplicon in polymerase chain reaction amplification w as obtained with the genomic L. collinoides IOEB 9527 DNA as template. The amino acid sequence deduced from the amplicon DNA sequence showed a very hi gh similarity and identity with the gene of gram-negative and C. pasteurian um species. After labeling, the amplicon was used as DNA probe in dot-blot hybridization with the genomic DNA of all the tested strains. Only strains that could degrade glycerol hybridized. Moreover, polymerase chain reaction s using GD1 and GD2 revealed only glycerol dehydratase genes of positive L. collinoides and L. hilgardii strains. The primers and the amplicon proved to be suitable and reliable tools to detect the lactic acid bacteria involv ed in the deterioration of cider.