Prolonged Culture of the Voracious Flagellate Peranema in Antioxidant‐Containing Media*

SYNOPSIS. Peranema trichophorum remained vigorous at least a year in milk‐lecithin media and 3 months in a nearly defined autoclavable biphasic agar medium fortified with the fat‐soluble antioxidant butylated hydroxytoluene. The only undefined substance in the present “defined” medium is crude soybean lecithin; 0.001% lecithin suffices in the presence of a mixture of long‐chain saturated and unsaturated fatty acids. Linoleic acid may be indispensable. Histidine is an absolute requirement as well as a favored substrate. Cholesterol, not ergosterol, satisfied the sterol requirement. Voracity is retained in these media as shown by engorgement on plastic latex particles.