Orange Serum-NPS are used for the detection and colony count of acidophilic and acidotolerant microorganisms in fruit juices, soft drinks and other beverages. The composition of this medium, i.e. the presence of orange serum, together with the low pH provides optimal growth conditions for acidophilic and acid tolerant microorganisms from beverages containing fruit juices or fruit components. The growth of accompanying microorganisms is slightly inhibited by the low pH. Incubation under anaerobic or microaerophilic conditions stimulates the growth of more demanding Lactobacilli. The medium is manufactured and quality tested in compliance with ISO 11133:2014 standard.