Fatty acid production characteristics of fungi with particular emphasis on gamma linolenic acid production.

The fatty acid production characteristics of fungi are described. These characteristics are the relationship between the oil content of the cell and the fatty acid content of the oil. For example, for polyunsaturated fatty acid (PUFA) production by Mucor hiemalis IPD 51, the oil content of the cell and the GLA content of the oil are coupled. For fungal production of some PUFA, synthesized after the rate-limiting step in the fatty acid anabolic chain, a maximum fatty acid production model was developed to link the fatty acid content of the oil and the oil content of the cell. Maximum volumetric productivity of gamma linolenic acid (GLA) by molds was found to occur at a specific GLA content of the oil. For example, for M. hiemalis IPD 51, a maximum volumetric of 4.7 mg GLA/L . h was produced at a GLA content of the oil of 8% to 10%. Similarly for Mucor circinelloides v. Tieghem IPD 155 a maximum volumetric productivity of 4.8 mg GLA/L . h was produced at a GLA content of the oil of 14% to 16%. These results imply that, when screening microorganisms for GLA or other fatty acid production, a number of medium compositions need to be evaluated to determine the tradeoff between oil content of the cell and fatty acid content of the oil.