Mycelial Lipid Composition of Three Penicillium Strains

¹ Laboratoire de Microbiologie Industrielle et de Génétique des Microorganismes, Ecole Nationale Supérieure Agronomique, Institut National de Recherche Agronomique, Place Viala, 34060 Montpellier Cedex, France
² Laboratoire de Chimie Organique, Ecole Nationale Supérieure de Chimie de Montpellier, 8 rue Ecole Normale, 34000 Montpellier, France

Lipid composition, particularly the fatty acid composition (C₆ to C₂₅), of two strains of Penicillium roqueforti and of one strain of Penicillium camemberti was determined. The neutral lipid fraction, which is essentially composed of intracellular triglycerides, and the polar lipid fraction, composed of membrane phospholipids, were analyzed separately using solvents that permitted their differential extraction: hexane for the neutral fraction and chloroform and methanol for the polar fraction. For the three strains and in the two fractions, the major fatty acids were linoleic, oleic, and palmitic acids, which formed 80% of the total fatty acids. Small amounts of -linolenic, dihomo -linolenic, and arachidonic acids were present. Penicillium camemberti contained 20 times more -linolenic acid than did P. roqueforti. The amount of short-chain fatty acids (C₆ to C₁₃) was always more important in the phospholipids than in the triglycerides. Penicillium roqueforti "Société" was the richest species in these fatty acids, which are the precursors of the methyl ketones that are responsible for the taste and the aroma of Blue cheese. The aging of the mycelium caused an enrichment of lipids in cells in the three strains.

Key Words: Penicillium camemberti • Penicillium roqueforti • lipid composition

Submitted on July 30, 1993
Accepted on February 28, 1994