A novel method to enhance the mycelia production of Ganoderma lucidum in submerged cultures by polymer additives and agitation strategies

The purpose of this research was to study the feasibility of the enhancement of mycelium production in the cultures of Ganoderma lucidum BCRC36123 by the control of morphological forms. Polymer additives and a novel agitation scheme were employed to vary mycelia morphology, which in turn led to higher mycelium production rates. The effect of various polymer additives on the mycelia growth was investigated in 250 mL flasks. The appearance of G. lucidum mycelia varied considerably ranging from large globes to tiny pellets. Agar, even at a lower concentration, was more effective than sodium alginate and polyacrylamide in shortening the size of pellets. When the agitation rate of the fermentor was maintained at 100 rpm, the mycelium concentration of 1.31 g/L was obtained in 5 days. Alternatively, an intermittent agitation scheme was employed and proved to be effective for enhancing mycelium production rate, causing the increase of mycelia concentration to 3.00 g/L. Moreover, when a polytron was connected with the fermentor, the level even rose to around 6.30 g/L. This study demonstrates that the control of mycelia morphology was very effective to enhance mycelium production of medicinal mushrooms in submerged cultures.