title: Enhanced production of ganoderic acids and cytotoxicity of Ganoderma lucidum using solid-medium culture.
abstract: Submerged cultures of Ganoderma lucidum are used to produce fungal mycelium, which is used as a functional food and in the production of various triterpenoids, including ganoderic acids (GAs). Specific culture approaches that produce fungal mycelium with high levels of GAs and good biological activity are critical in the functional food industry. In this study, a solid-medium culture approach to producing mycelium was compared to the submerged culture system. Production of GAs, biomass, intracellular polysaccharides, and cytotoxicity of the cultured mycelium were compared as between solid and submerged culture. Growing G. lucidum strains on solid potato dextrose agar medium increased biomass, the production of ganoderic acid 24 (lanosta-7,9(11), 24-trien-3α-o1-26-oic acid), GAs, and total intracellular polysaccharides as compared to fungi grown in submerged culture. Triterpenoid-enriched methanol extracts of mycelium from solid-medium culture showed higher cytotoxicity than those from submerged culture. The IC(50) values of methanol extracts from solid-medium culture were 11.5, 8.6, and 9.9 times less than submerged culture on human lung cancer cells CH27, melanoma cells M21, and oral cancer cells HSC-3 respectively. The squalene synthase and lanosterol synthase coding genes had higher expression on the culture of solid potato dextrose medium. This is the first report that solid-medium culture is able to increase GA production significantly as compared to submerged culture and, in the process, produces much higher biological activity. This indicates that it may be possible to enhance the production of GAs by implementing mycelium culture on solid medium.
authors.affiliation: Department of Chinese Pharmaceutical Sciences and Chinese Medicine Resources, China Medical University, Taichung, Taiwan.
authors.forename: Bang-Jau
authors.initials: BJ
authors.lastname: You
authors.forename: Hong-Zin
authors.initials: HZ
authors.lastname: Lee
authors.forename: Kuang-Ren
authors.initials: KR
authors.lastname: Chung
authors.forename: Miin-Huey
authors.initials: MH
authors.lastname: Lee
authors.forename: Mei-Jung
authors.initials: MJ
authors.lastname: Huang
authors.forename: Ni
authors.initials: N
authors.lastname: Tien
authors.forename: Chiao-Wei
authors.initials: CW
authors.lastname: Chan
authors.forename: Yueh-Hsiung
authors.initials: YH
authors.lastname: Kuo
mesh_terms: D000362:Agar; D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D045424:Complex Mixtures / Q000737:chemistry / Q000494:pharmacology*; D003470:Culture Media; D013186:Farnesyl-Diphosphate Farnesyltransferase / Q000235:genetics / Q000378:metabolism; D005285:Fermentation; D062610:Fungal Polysaccharides / Q000096:biosynthesis; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression; D006801:Humans; D020128:Inhibitory Concentration 50; D019751:Intramolecular Transferases / Q000235:genetics / Q000378:metabolism; D007810:Lanosterol / Q000031:analogs & derivatives / Q000096:biosynthesis*; D000432:Methanol; D025282:Mycelium / Q000737:chemistry* / Q000378:metabolism; D020940:Reishi / Q000737:chemistry* / Q000378:metabolism; D012997:Solvents; D014315:Triterpenes / Q000378:metabolism*
chemical_list: D000970:Antineoplastic Agents; D045424:Complex Mixtures; D003470:Culture Media; D062610:Fungal Polysaccharides; D005656:Fungal Proteins; D012997:Solvents; D014315:Triterpenes; C556862:ganoderic acid; D007810:Lanosterol; D000362:Agar; D013186:Farnesyl-Diphosphate Farnesyltransferase; D019751:Intramolecular Transferases; C021924:lanosterol synthase; D000432:Methanol