Enhanced production of exopolysaccharides by fed-batch culture of Ganoderma resinaceum DG-6556.
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.
Kim
Hyun Mi
HM
Department of Biotechnology, College of Engineering, Daegu University, Kyungsan, Kyungbuk 712-714, Republic of Korea.
Paik
Soon-Young
SY
Ra
Kyung Soo
KS
Koo
Kwang Bon
KB
Yun
Jong Won
JW
Choi
Jang Won
JW
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
D011134:Polysaccharides; D005947:Glucose