Table 3. Antimicrobial activity of crude bacteriocin produced by Lactobacillus acidophilus KCNU

Sample	Treatment condition	Antimicrobial activity1) (AU/mL)
Filtration	Filtration through a 0.45 μm membrane	6,400
Heat-treatment	Heat treatment (65°C for 20 min) followed by 0.45 μm membrane filtration	6,400
Vacuum concentration	Vacuum evaporation at 55°C	6,400
Freeze-drying	Heat treatment (65°C for 20 min) followed by freeze-drying (–50°C, 6 torr)	6,400

Antimicrobial activity was expressed as arbitrary unit per milliliter (AU/mL) using the formula (1,000 μL/10 μL)×reciprocal of the highest dilution showing visible inhibitory activity.