Influence of culture medium growth variables on Ganoderma lucidum exopolysaccharides structural features

• Published in: Carbohydrate polymers 2014-10, Vol.111, p.936-946
• Main Authors: Fraga, Irene, Coutinho, João, Bezerra, Rui M., Dias, Albino A., Marques, Guilhermina, Nunes, Fernando M.
• Format: Article
• Language: English
• Subjects: Applied sciences; Bioconversions. Hemisynthesis; Biological and medical sciences; Biomass; Biotechnology; Cell Culture Techniques - methods; Central composite design; Culture Media - chemistry; Culture Media - metabolism; Exact sciences and technology; Exopolysaccharides; Fundamental and applied biological sciences. Psychology; Ganoderma lucidum; Hydrogen-Ion Concentration; Methods. Procedures. Technologies; Natural polymers; Physicochemistry of polymers; Polysaccharides - chemistry; Polysaccharides - metabolism; Reishi - chemistry; Reishi - growth & development; Reishi - metabolism; Response surface methodology; Starch and polysaccharides; Structural features; Submerged culture conditions
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2014.05.047

•Ganoderma lucidum produces bioactive extracellular polysaccharides (EPS).•EPS are mainly β-(1→4)-linked branched glucans containing also (1→3) linkages.•Optimum conditions for biomass and EPS production were significantly different.•Structural features of EPS were dependent on the growth conditions.•These differences may have an effect on the biological activity of the EPS produced. In this work the effect of carbon and nitrogen levels and initial pH of the wheat extract culture medium of submerged culture of Ganoderma lucidum on the amount, purity and structural features of exopolysaccharides (EPS) were studied. A low peptone level (1.65gL−1) favored mycelium biomass, EPS purity, but a higher supply of peptone (4.80gL−1) is needed for maximum EPS production. The carbohydrate composition of the EPS and structural features also changed significantly according to the different growing conditions, being observed significant differences in the (1→3)/(1→4)-Glcp ratio and also on the branching degree of EPS. As the biological activities of EPS are highly dependent on the polysaccharide structural features, this variability can have implications on the EPS biological activities, but can also be used advantageously to produce tailor made polysaccharides with specific applications.