Sequence of DNA 16S/23S spacer region of Leuconostoc oenos (Oenococcus oeni): application to strain differentiation.

Leuconostoc oenos is involved in malolactic fermentation occurring during wine-making. An increasing number of wines are being inoculated with malolactic starters to control the process, and the identification and differentiation of selected strains are now indispensable both for quality control of production and for commercial purposes. In the present work we evaluated the potential use of the intergenic regions of three L. oenos strains for their differentiation. The three 16S/23S rRNA intergenic spacers were amplified in vitro by PCR, and sequences were compared. The spacer sequence was highly conserved in all strains. Inside this spacer, a tRNA-Ala gene containing an 18-bp sequence stretch which is conserved in all tRNA genes was discovered. This sequence, together with random primers, was used for characterization of ten L. oenos strains by PCR.