Ten grams of fish gut was added to 90 ml of sterile peptone
(0.1%) water and then thoroughly homogenized for 1 min
in a Laboratory Blender Stomacher. From appropriate 10-
fold dilutions, 100 μl was spread on modified deMan
Rogosa Sharpe (MRSm) agar (containing 0.2% w/v glucose
and supplemented with 50 μl/ml of cyclohexamide,
Himedia) plates and incubated anaerobically at 30 °C for
24 h. After anaerobic incubation, the plates that provided
separated bacterial colonies were overlaid with 10 ml of
nutrient soft (0.7%) agar (Himedia) containing approximately
106 cells of Staphylococcus aureus ATCC 25923.
The plates were anaerobically incubated at the optimal
growth temperature for the indicator organism. The plates
are then checked for inhibition zones around colonies of
isolated lactic acid bacteria (Rattanachaikunsopon and
Phumkhachorn