The bacteria (107 CFU mL−1)
were grown in peptone water and incubated at 30 °C for
48 h. The culture broth was centrifuged at 4 °C at 10,000×g
for 15 min. The supernatant was collected and mixed with
0.5mL ofNessler’s reagent (Hach company, Loveland, USA).
Development of brown to yellow color was recorded as a
positive test for ammonia production (Cappuccino and
Sherman 2001). All experiments were done in five replicates.