Given the availability of raw materials, apple cider vinegar is often produced by households for their own needs using a traditional spontaneous process carried out by a native microbiota present on the fruit. Further chemical analysis should reveal if a difference in microbiota composition influences the quality of different types of apple cider vinegar.Īpple cider vinegar, alongside wine and alcohol vinegars, is one of the three most common vinegars available on the European market. This study has shown for the first time that the bacterial microbiota for the industrial production of organic apple cider vinegar is clearly more heterogeneous than the bacterial microbiota for the industrial production of conventional apple cider vinegar. Yeasts that are able to resist 30 g/L of acetic acid were isolated from the acetic acid production phase and further identified by sequence analysis of the ITS1−5.8S rDNA‒ITS2 region as Candida ethanolica, Pichia membranifaciens and Saccharomycodes ludwigii. Using the same analytical approach in conventional apple cider vinegar, we identified only two different HaeIII and two different HpaII restriction profiles of the 16S‒23S rRNA gene ITS regions, which belong to the species Acetobacter pasteurianus (66.70%) and Komagataeibacter oboediens (33.30%). Each type of restriction profile was further analyzed by sequence analysis of the 16S−23S rRNA gene ITS regions, resulting in identification of the following species: Acetobacter pasteurianus (71.90%), Acetobacter ghanensis (12.50%), Komagataeibacter oboediens (9.35%) and Komagataeibacter saccharivorans (6.25%). Using the restriction analysis of the PCR-amplified 16S−23S rRNA gene ITS regions, we identified four different HaeIII and five different HpaII restriction profiles for bacterial isolates from organic apple cider vinegar. In this way we isolated and characterized 96 bacteria from organic and 72 bacteria from conventional apple cider vinegar. We compared the cultivable acetic acid bacterial microbiota in the production of organic and conventional apple cider vinegars from a smoothly running oxidation cycle of a submerged industrial process. In both, the organic and conventional apple cider vinegars the ethanol oxidation to acetic acid is initiated by native microbiota that survived alcohol fermentation. The produced ethanol is used as a substrate by acetic acid bacteria in a second separated bioprocess. During the first stage of the process, the sugars from apples are fermented by yeasts to cider. Organic apple cider vinegar is produced from apples that go through very restricted treatment in orchard.
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