Enhancement of gamma-linolenic acid production by the fungus Mucor SP LB-54 by growth temperature

Abstract

As a relatively prolific producer of GLA, the strain of Mucor sp LB-54 was selected for a study at different growth temperatures in shaker flask culture. The strain used in our experiment was capable to accumulate a relatively high amount of intracellular lipid, 20.73% of dry cell weight, and GLA content of 15% of total fatty acids after 5 days of incubation at 28°C. As the growth temperature was decreased from 28 to 12°C the percentage of GLA increased from 15 to 24% of total fatty acids. In order to optimize the culture conditions for rapid biomass production and lipid production with a high proportion of GLA, the fungus was grown at two temperature combinations associated supplies of carbon source (glucose) in the culture medium. Maximal production of GLA (74 mg/l) was obtained from the Mucor sp LB-54 strain after 5 days of incubation at 28°C in basal medium following glucose addition (7% w/v) and incubation for an additional 3 days at 12°C. The identity of GLA found in the strain of Mucor sp LB-54 was confirmed by the coupled gas chromatography-mass spectrometry.