Isolation and fatty acid analysis of lipid-producing endophytic fungi from wild Chinese Torreya Grandis

Torreya grandis is a rare tree species of economic value. Its seeds are rich in lipids, although their use is limited by their high cost. Recent studies demonstrated that certain endophytic fungi can produce metabolites similar to those produced by the host plant. In the present study, endophytic fungal strains capable of producing lipids were isolated from wild Chinese Torreya grandis. Among these, the XF-38 strain had the highest lipid content at 17.68%. Comparative analysis of the fatty acid composition of lipids produced by endophytic fungi and Torreya seeds by GC-MS showed that the two sources shared some of the same components, including linoleic acid, oleic acid, and sciadonic acid (5c, 11c, 14c-eicosatrienoic acid). The morphology and internal transcribed spacer rDNA of the XF-38 strain were determined, and a BLAST search showed that this strain belongs to Bionectria ochroleuca . Finally, generation of a growth curve and determination of the lipid content of strain XF-38 confirmed that lipid production was related to the amount of mycelium, and the lipid content resched 3.1 g/L in the microcrystalline cellulose meduim.