Effect of glutamate on arachidonic acid production from Mortierella alpina

Aims: To evaluate the effect of glutamate on arachidonic acid production from Mortierella alpina . Methods and Results: Cell growth, arachidonic acid production, proportions of poly-unsaturated fatty acids (PuFAs) in fatty acids and glucose-6-phosphate dehydrogenase (G6PDH) activity were analysed when glutamate concentration was 0.8 g l(-1) . Biomass and arachidonic acid production were higher in the culture containing glutamate than those in the control culture, and both reached their maximum of 25 g l(-1) and 1.4 g l(-) (1) after 7 d, respectively. The proportions of some PuFAs, oleic acid, gamma -linolenic acid and dihomo-gamma -linolenic acid were decreased while linoleic acid and arachidonic acid were enhanced by glutamate addition. Glutamate addition enhanced G6PDH activity compared with the control during the whole culture process. Conclusions: Addition of 0.8 g l(-1) glutamate was beneficial to enhance arachidonic acid production from Mortierella alpina , which was a result of activating the pentose phosphate pathway (PPP). Significance and Impact of the Study : This study shows that the addition of glutamate and regulation of PPP had a positive influence on arachidonic acid synthesis in Mortierella species.