Design and evaluation of malolactic enzyme gene targeted primers for rapid identification and detection of Oenococcus oeni in wine.

Rapid identification and detection of Oenococcus oeni was achieved by species-specific PCR. Two primers flanking a 1025 bp region of the O. oeni gene encoding the malolactic enzyme were designed. The expected DNA amplificate was obtained only when purified DNA from O. oeni was used. The identity of PCR product was confirmed by nested PCR and restriction analysis. Within 8 h, 10(3) cfu ml-1 of oenococci were detected in fermenting grape must containing 10(7) yeast cells, whereas the detection limit in wine was 10(4) cfu ml-1. The rapidity and reliability of the PCR procedure established suggests that the method may be profitably applied in winery laboratories for quality control.