**3.2. Mesophilic aerobic bacteria**

The mesophilic count, or standard plate count, is generally obtained on Plate Count agar (PCA) which is a generic medium for aerobic microorganisms that grow at mesophilic temperatures. Aerobic plate counts are poor indicators of safety in some products such as those fermented which commonly show a high aerobic count. However, this count gives information about the hygienic and sensorial quality, about the adherence to good manufacturing practice and shelf life of the product (Morton, 2001).

Alternatively to PCA, similar generic media are available as Nutrient agar. The growth conditions are 25-30°C for 24-48 hours, aerobically.
