Determination of protein content
Protein concentrations in the extracellular extracts of LAB were
determined using the Bradford method.17 First, 100 mL of the
sample was mixed with 100 mL of distilled water and 800 mL of
Bradford reagent. The mixture was allowed to stand at room temperature
for 5 minutes, and the absorbance of each sample was
measured at 596 nm. The standard curve of protein concentration
was constructed using a series of dilutions of the Bovine Serum
Albumin (BSA) protein standard stock solution.