Effect of fatty acids on the mycelial growth and polysaccharide formation by Ganoderma lucidum in shake flask cultures

Fatty acids were added into the media to investigate their effects on the mycelial growth and polysaccharide formation by Ganoderma lucidum. The experiments were carried out in freely suspended cultures or immobilized cultures using shake flasks. The results indicate that the extent of stimulation or inhibition were associated with the types and levels of fatty acids. Oleic acid at the level of 0.15 g/100 ml led to a significant increase in cell concentration from 0.20 to 0.46 g/100 ml in a suspended culture and palmitic acid was of great advantage to polysaccharide production. In contrast, linoleic acid (0.1 g/100 ml) drastically suppressed both mycelial growth and polysaccharide formation. In immobilized cultures with fatty acids, the stimulation of mycelial growth remained the same level, but the enhancement of polysaccharide production became less. In addition, the growth of G. lucidum in the pattern of immobilization might be beneficial to the production of mycelia and polysaccharide.