Figure 3.

Ontological model of kefir fermentation. Solid arrows represent semantic relations in RO (annotated with their label), while dashed arrows represent hierarchical relationships (i.e., “is a” relation). Pink and blue rectangles refer to process or material entity, respectively. The label and the term ID (formatted as an ontology prefix followed by a number) are reported for each class. Classes are generally conceptualized to the universal level (i.e., the definition and concepts apply to any possible class instance). When suitable, instance-level concepts (indicated with white rhombus) are used to indicate a particular instance of the universal concept. For example, the prevalent bacteria genera in kefir microbiota are specific instances of the universal “bacteria” (or taxonomical subclassifications) concept (i.e., only some specific instances of the Acetobacter genus are active ingredients of the kefir microbiota, but not the entirety of the Acetobacter concept).