Partial purification of an antifungal protein produced by Enterococcus faecalis CHD 28.3

The antifungal protein produced by Enterococcus faecalis CHD 28.3 isolated from the Cheddar cheese was partially purified from the culture supernatant using ultrafiltration, anion exchange and gel filtration chromatography. Employing a 10 kDa cut off membrane, ultrafiltration of the culture supernatant resulted in a recovery of 44.6% of the antifungal protein with 1.7 fold increase in the specific activity. Anion-exchange chromatography using DEAE-Sepharose matrix followed by purification of the samples using high resolution gel filtration chromatography employing Superose-12 column/FPLC system led to a very low (similar to 0.5%) recovery of antifungal activity with an increase in specific activity by 11.9 fold relative to initial value in crude supernatant. The molecular mass of the antifungal protein from the high resolution gel filtration was estimated to be around 11 KDa. The partially purified protein obtained after DEAE-Sepharose chromatography step was completely inactivated by heat treatment at 72 degrees C for 15 seconds.