GROWTH OF FUSARIUM DIVERSISPORUM SHERB. ON LONG-CHAINn-FATTY ALCOHOLS OR CHOLESTEROL AS THE SOLE CARBON SOURCE

Abstract

In well-aerated submerged cultures of Fusarium diversisporum Sherb. with n-hexadecanol or n-heptadecanol (which are virtually water insoluble) as the sole carbon source, the alkanols do not undergo extracellular chemical changes before assimilation but move, unchanged, through the cell wall faster than they can be metabolized by the organism and thus may constitute up to one-half of the total lipids in the cells. The alkanols are initially oxidized at the hydroxylated terminal carbon atom to fatty acids without loss of carbon. The fatty acids are subject to further metabolic action. Apparently carbon, not needed immediately for energy and for synthesis of cell components, is transformed into triglycerides as a reserve material. In these triglycerides, the distribution of the saturated and the unsaturated fatty acids between the primary and the secondary positions of the glycerol moiety is one typical of a vegetable lipid. Interesting differences exist, particularly in the sterol ester and phospho- or glyco-lipid contents, between mycelia grown on sucrose, hexadecanol, or heptadecanol. These cell constituents may possibly be involved in alkanol transport across the cell wall. The mold also assimilates cholesterol but has difficulty in metabolizing it.