The phenotypic approach (i.e., the identifi cation based on assimilation – fermentation– growth challenges)
has been the first to be applied และ is still in use, despite its drawbacks regarding reliability และ accuracy,
even at species level.
The most frequently applied และ most reliable technique is sequencing of the 16S - rRNA gene.
This technique has been applied either in combination with other techniques,
such as SDS - PAGE of whole cell proteins, RAPD - PCR, or PFGE, or directly to the isolated microorganism.
Although this approach provides accurate identifi cation at strain level,
An equally important part of the microbiota, namely the viable but not culturable fraction,
is not taken into consideration.
This weakness can be addressed by the application of techniques such as PCR - DGGE,
Which instead of relying on culturing of the bacteria,
incorporates the direct extraction of the DNA from the food sample. Furthermore,