Characterization of hemolytic and antifungal substance, cepalycin, from Pseudomonas cepacia

Abstract

Hemolytic and antifungal substances, cepalycin I and cepalycin II, have been isolated from Pseudomonas cepacia JN106. A large amount of cepalycins were produced by growing the cells on 1% glycerin-nutrient agar medium covered with a cellophane membrane. The cell-washed supernatant was applied to an Amberlite XAD2 column, and cepalycins were eluted with 70% ethanol containing 1mM HCl. Cepalycins were separated by reverse phase HPLC in two fractions which were designated as cepalycin I and cepalycin II. The two cepalycins have indistinguishable UV absorption spectra but have different levels of hemolytic activity relative to the UV absorption. From the inhibition of hemolytic activity of cepalycin by sterols, both cepalycins were suggested to interact with cholesterol in erythrocyte membrane. Such an interaction may contribute to their hemolytic and antifungal activities.