Bioprocess Optimization for Exopolysaccharides Production by Ganoderma lucidum in Semi-industrial Scale

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. Objective: This work focuses on the development of a simple cultivation strategy for exopolysaccharides (EPS) production using Ganoderma lucidum and submerged cultivation system. Results and Discussion: Therefore, this work is focused on the development of simple cultivation system for exopolysaccharides (EPS) production using Ganoderman lucidum. At first, the best medium supporting EPS production was chosen experimentally from the current published data. Second, like many EPS production process, carbon and nitrogen concentrations were optimized to support the highest production of polysaccharides in shake flask level. Furthermore, the process was scaled up in 16-L stirred tank bioreactor. The results clearly demonstrated that the best cultivation strategy was cultivation under controlled pH condition (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. Methods: 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. Conclusion: The current results clearly demonstrates the high potential use of submerged cultivation system as alternative to conventional solid state fermentation for EPS production by G. lucidum. Furthermore, optimization of both carbon and nitrogen sources concentration and scaling up of the process showed significant increase in both volumetric and specific EPS production.