Fermentative Production of Nervonic Acid by Mortierella capitata RD000969

抄録

A high-nervonic acid (cis-15-tetracosenoic acid, C_24:1, n-9)-producing filamentous fungus of the Mortierella species was discovered among soil filamentous fungi. The filamentous fungal strain –RD000969– was isolated from soil collected in Kanagawa Prefecture (Japan) and was found to accumulate nervonic acid at a rate of 6.94% of the total cellular fatty acids. The base sequences of 28S rDNA D1/D2 and ITS 5.8S rDNA showed 100% homology with Mortierella capitata CBS 293.96. In addition to nervonic acid, strain RD000969 produced a large amount of long-chain monounsaturated fatty acids (C_20:1, 12.22%; C_22:1, 4.07%; C_26:1, 5.91%) and a small amount of ultra-long-chain fatty acids (C_28:1, 0.44%; C_30:1, 0.06%; C_32:1, trace). In the fungal cells, 98.87% of nervonic acid was localized at the sn-1,3 position of triacylglycerol. Nervonic acid production was maximum (186.3 mg・L^–1) when the fungus was cultured in potato dextrose (PD) medium containing yeast extract, CaCl₂, and MgSO₄・7H₂O.