Arachidonic-acid production by species of Mortierella.

A growth-inhibiting, aspirin-containing medium was developed to select arachidonic-acid-(ARA)-producing Mortierella species and to determine the fatty-acid content of 87 Mortierella strains. ARA was detected in 66 strains from 33 species and its production may prove useful for systematic studies on Mortierella spp. The ARA content of the 66 producing strains tested ranged from 4% to 55% of total lipids. Most of the ARA-producing strains of Mortierella (59 strains) grown on potato/glucose/agar synthesized <20% ARA. Four strains produced between 20% and 25% ARA and three produced >40%. An inverse relationship was observed between ARA and oleic-acid contents.