Stimulatory effects of Coix lacryma-jobi oil on the mycelial growth and metabolites biosynthesis by the submerged culture of Ganoderma lucidum

• Stimulation of Coix lacryma-jobi oil (CLO) on the biomass of Ganoderma lucidum.
• Enhancement of CLO on polysaccharide biosynthesis of G. lucidum.
• CLO does not change the biosynthesis pathway of polysaccharides.
• CLO affects synthesis level of some enzymes related to polysaccharide production.

Effects of Coix lacryma-jobi oil (CLO) addition on the mycelia growth and production of bioactive metabolites, such as triterpenoids, exopolysaccharide (EPS), and intracellular polysaccharide (IPS) in the submerged culture of Ganoderma lucidum were studied. The results showed that when a level of 2% CLO was added at the beginning of culture, the biomass, triterpenoids, EPS, and IPS productions reached a maximum of 10.71 g/L, 92.94 mg/L, 0.33 g/L, and 0.389 g/L, respectively, that were 3.34-fold, 2.76-fold, 2.2-fold, and 2.23-fold compared to that of control. Analysis of fermentation kinetics of G. lucidum suggested that glucose concentration in the culture of CLO-added group decreased more quickly as compared to the control group from day 2 to day 7 of fermentation process, while the triterpenoids and polysaccharides biosynthesis were promoted at the same culture period. However, the culture pH profile was not affected by the addition of CLO. There were no new components in the two types of polysaccharides obtained by the addition of CLO. Enzyme activities analysis indicated CLO or its fatty acids affected the synthesis level of phosphoglucose isomerase and α-phosphoglucomutase at different stage.