Mucor--a source of cocoa butter and gamma-linolenic acid

Lipid analyses were performed on 28 strains of various species of the genus Mucor. In shake flasks with glucose as carbon source, the gamma-linolenic acid (GLA) content in the neutral lipid (NL) fraction of some Mucor species was up to 38 mg GLA/g dry biomass. Some Mucor species produced more than 20% (w/w) stearic acid (18:0) and more than 60% of their NL content as symmetrical triacylglycerols (SUS-TAGs) which corresponded to those of cocoa butter. Three Mucor species were evaluated in terms of the production of SUS-TAGs and GLA in pH-stat, fed-batch cultures in an air-lift fermenter with acetic acid as titrant and carbon source. Mucor circinelloides f. circinelloides CBS 108.16 accumulated 27% 18:0 in the NL fraction, which constituted approximately 40% of the dry biomass. In this case, the NL fraction contained more than 70% (w/w) SUS-TAGs.