title: Enhanced production of exopolysaccharides by fed-batch culture of Ganoderma resinaceum DG-6556.
abstract: The objectives of this study were to optimize submerged culture conditions of a new fungal isolate, Ganorderma resinaceum, and to enhance the production of bioactive mycelial biomass and exopolysaccharides (EPS) by fed-batch culture. The maximum mycelial growth and EPS production in batch culture were achieved in a medium containing 10 g/l glucose, 8 g/l soy peptone, and 5 mM MnCl(2) at an initial pH 6.0 and temperature 31 degrees C. After optimization of culture medium and environmental conditions in batch cultures, a fed-batch culture strategy was employed to enhance production of mycelial biomass and EPS. Five different EPS with molecular weights ranging from 53,000 to 5,257,000 g/mole were obtained from either top or bottom fractions of ethanol precipitate of culture filtrate. A fed-batch culture of G. resinaceum led to enhanced production of both mycelial biomass and EPS. The maximum concentrations of mycelial biomass (42.2 g/l) and EPS (4.6 g/l) were obtained when 50 g/l of glucose was fed at day 6 into an initial 10 g/l of glucose medium. It may be worth attempting with other mushroom fermentation processes for enhanced production of mushroom polysaccharides, particularly those with industrial potential.
authors.affiliation: Department of Biotechnology, College of Engineering, Daegu University, Kyungsan, Kyungbuk 712-714, Republic of Korea.
authors.forename: Hyun Mi
authors.initials: HM
authors.lastname: Kim
authors.forename: Soon-Young
authors.initials: SY
authors.lastname: Paik
authors.forename: Kyung Soo
authors.initials: KS
authors.lastname: Ra
authors.forename: Kwang Bon
authors.initials: KB
authors.lastname: Koo
authors.forename: Jong Won
authors.initials: JW
authors.lastname: Yun
authors.forename: Jang Won
authors.initials: JW
authors.lastname: Choi
mesh_terms: D005285:Fermentation; D032902:Ganoderma / Q000254:growth & development* / Q000302:isolation & purification / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007218:Industrial Microbiology / Q000379:methods*; D025282:Mycelium / Q000254:growth & development / Q000378:metabolism; D011134:Polysaccharides / Q000096:biosynthesis*; D013696:Temperature
chemical_list: D011134:Polysaccharides; D005947:Glucose