Background: For many years, Ganoderma was highly considered as biofactory for the
production of different types of bioactive metabolites. Of these bioactive compounds, polysaccharides
gained much attention based on their high biotherapeutic properties. Therefore, special attention
has been paid during the last years for the production of mushrooms bioactive compounds in a
closed cultivation system to shorten the cultivation time and increase the product yield.
Objectives: This work focuses on the development of a simple cultivation strategy for exopolysaccharides
(EPS) production using Ganoderma lucidum and submerged cultivation system.
Methods: At first, the best medium supporting EPS production was chosen experimentally from the
current published data. Second, like many EPS production processes, carbon and nitrogen concentrations
were optimized to support the highest production of polysaccharides in the shake flask
level. Furthermore, the process was scaled up in 16-L stirred tank bioreactor.
Results: The results clearly demonstrated that the best cultivation strategy was cultivation under
controlled pH conditions (pH 5.5). Under this condition, the maximal volumetric and specific yield
of EPS production were, 5.0 g/L and 0.42 g/g, respectively.
Conclusion: The current results clearly demonstrate the high potential use of submerged cultivation
system as an alternative to conventional solid-state fermentation for EPS production by G. lucidum.
Furthermore, the optimization of both carbon and nitrogen sources concentration and scaling up of
the process showed a significant increase in both volumetric and specific EPS production.