Evaluation of inoculum performance for enhancing gamma-linolenic acid production from Mucor rouxii

To facilitate a cost-effective preparation of spore inoculum with good capacity for gamma-linolenic acid (GLA) production from Mucor rouxii.

Sporangiospore production, mycelial growth ability and fatty acid composition of M. rouxii were determined. Compared with fungal cultivation on solid semi-synthetic media, high spore production was achieved from M. rouxii grown on rice grains, particularly polished rice (30.7 g kg(-1) initial substrate). Variations in the fatty acid profiles were found in the spores grown on different types of solid media, whereas the spores obtained at different ages from cultivated polished rice showed a similar fatty acid profile. Using the inocula from different spore-forming media and culture ages, and low temperature storage, not much change in the vegetative growth of submerged cultures or fatty acid composition of mycelia was observed.

The spores generated on polished rice exhibited a high performance for GLA production. Age of spore and timing of spore storage at low temperature did not affect on fatty acid profile of the mycelial cultures.

The simple, low cost method of inoculum preparation can be applied for large-scale production of GLA-rich oils, which reduce a time constraint and variation in fatty acid composition.