Evaluation and optimisation of bacterial genomic DNA extraction forno-culture techniques applied to vinegars

Direct genomic DNA extraction from vinegars was set up and suitability for PCR assaysperformed by PCR/DGGE and sequencing of 16S rRNA gene. The method was tested on 12intermediary products of special vinegars, fruit vinegars and condiments produced from different rawmaterials and procedures. DNAs extraction was performed on pellets by chemical, enzymatic, resinmediated methods and their modifications. Suitable yield and DNA purity were obtained bymodification of a method based on the use of PVP/CTAB to remove polyphenolic components andesopolysaccharides. By sequencing of bands from DGGE gel, Ga. europaeus, A. malorum/cerevisiae andA. orleanensis were detected as main species in samples having more than 4% of acetic acid content.From samples having no acetic acid content, sequences retrieved from excised bands revealed highsimilarity with prokaryotes with no function on vinegar fermentation: Burkholderia spp, Cupriavidusspp., Lactococcus lactis and Leuconostoc mesenteroides. The method was suitable to be applied for noculturestudy of vinegars containing polyphenols and esopolysaccharides allowing a more completeassessment of vinegar bacteria.