Lipid and Sterol Content of Some Protozoa*

Abstract

Total lipids of several protozoa were determined and found higher than in most other microorganisms. The lipid content in a phytoflagellate, Ochromonas malhamensis, could be increased by excess nicotinic acid or deficiency in nitrogen supply. Cell multiplication and lipid synthesis were unaffected by inhibitors of vitamin synthesis such as penicillamine, pan‐toyltaurine, or pyridine‐3‐sulfonic acid, up to 100 mg%. The phytoflagellates, O. danica, O. malhamensis, Euglena gracilis, and the photosynthetic bacterium Chlorobium limkola contained large quantities of non‐saponifiable lipids: ergesterol was identified as a major component of this lipid fraction. Sterols were not found in the bacteria, Streptococcus faecalis, Rhodopseudomonas palustris; the algae. Cyanidium calidarnm. Anacystis nidulans, and Porphyridium cruentum; and the protozoan Tetrahymena pyriformis.

The Sterol Content of Some Protozoa

“…Ergosterol has previously been reported to occur in Ochromonas danica ( 1,19) ; Aaronson & Baker stated that it is also present in 0. malhamensis. Although in the present investigation 59.5 g of freeze-dried 0. malhamensis were extracted, no ergosterol was detected.…”

“…Detection and estimation of sterols. (1) Liebermann-Burchard ( L B ) reaction. This colorimetric reaction was carried out by dissolving an aliquot of the sterol in 3 ml glacial acetic acid.…”

Cholesterol Inhibition of Pentacyclic Triterpenoid Biosynthesis in Tetrahymena pyriformis*†

“…Squalene gives rise to both tetracyclic and pentacyclic triterpenoids, as anticipated by Eschenmoser et al Goodwin's group for P-amyrin, a pentacyclic triterpenoid alcohol found in plants (17,33,40) and is reported herein for tetrahymanol. The lipid content of Tetrahymena pyriformis has been examined both chemically and cytochemically by a large number of investigators (1,14,30,31,32,38,39). These cells possess lipid granules composed primarily of triglycerides which contain saturated or monounsaturated fatty acids, structural lipid components (tetrahymanol, phospholipids) and lipoids such as coenzyme Q 8 (42) and an unusual sphingosine (6).…”

Lipid Composition of Trypanosoma ranarum.

“…phytoflagellates contain ergosterol as their major sterol, as has been shown with EugZem gracillis and Ochromonas donica (8,12 ) , The phytoflagellates are, however, a heterogeneous group occupying a systematic position at intersections of plant and animal lines of descent ( 13). They include resistance of both groups to most bacterial antibiotics, and a parallel susceptibility to chema-after 11/2 min, and calculated as ergostwol.…”