The use of Ultra-Violet Irradiated Culture Media for Securing Bacteria-Free Cultures of Saprolegnia

SUMMARY

Bacteria-free cultures of Saprolegnia were readily obtained from badly contaminated sources by first growing the organism on an ultra-violet-irradiated medium containing levulose, peptone and agar. The ease of obtaining bacteria-free cultures by this method depends upon the fact that the irradiation so alters the culture medium that growth of bacteria is greatly inhibited with little or no inhibition of the development of the fungus. It is thought that this method will be applicable to the isolation of other fungi.

The authors wish to acknowledge their indebtedness to Professor William H. Weston Jr. for the helpful suggestions offered during this investigation.