characteristic of determined by role food preservation process altered effects of pH on population growth altered population growth in high osmolarity altered population growth at high temperature kefir microbiota agent for physico-chemical selection of microbiota https://orcid.org/0000-0001-9446-7979 https://orcid.org/0000-0002-7114-7726 a chemical and/or physical factor that exerts selection pressure and brings about natural selection within microbiota components https://github.com/FrancescoVit parmigiano reggiano microbiota