title: Improving the fermentation production of the individual key triterpene ganoderic acid me by the medicinal fungus Ganoderma lucidum in submerged culture.
abstract: Enhanced ganoderic acid Me (GA-Me, an important anti-tumor triterpene) yield was attained with the medicinal fungus Ganoderma lucidum using response surface methodology (RSM). Interactions were studied with three variables, viz. glucose, peptone and culture time using a Central Composite Design (CCD). The CCD contains a total of  20 experiments with the first 14 experiments organized in a fractional factorial design, with the experimental trails from 15 to 20 involving the replications of the central points. A polynomial model, describing the relationships between the yield of GA-Me and the three factors in a second-order equation, was developed. The model predicted the maximum GA-Me yield of 11.9 mg&#183;L&#8722;1 for glucose, peptone, culture time values of 44.4 g&#183;L&#8722;1,  5.0 g&#183;L&#8722;1, 437.1 h, respectively, and a maximum GA-Me yield of 12.4 mg&#183;L&#8722;1 was obtained in the validation experiment, which represented a 129.6% increase in titre compared to that of the non-optimized conditions. In addition, 11.4 mg&#183;L&#8722;1 of GA-Me was obtained in a 30-L agitated fermenter under the optimized conditions, suggesting the submerged culture conditions optimized in the present study were also suitable for GA-Me production on a large scale.
authors.affiliation: Hunan Provincial Key Laboratory of Forestry Biotechnology, College of Life Science and Technology, Central South University of Forestry and Technology, Changsha, China. gaoliuedu@yahoo.com.cn
authors.forename: Gao-Qiang
authors.initials: GQ
authors.lastname: Liu
authors.forename: Xiao-Ling
authors.initials: XL
authors.lastname: Wang
authors.forename: Wen-Jun
authors.initials: WJ
authors.lastname: Han
authors.forename: Qin-Lu
authors.initials: QL
authors.lastname: Lin
mesh_terms: D000465:Algorithms; D000704:Analysis of Variance; D019149:Bioreactors; D003470:Culture Media / Q000737:chemistry; D046508:Culture Techniques; D004365:Drugs, Chinese Herbal / Q000378:metabolism; D005285:Fermentation; D008954:Models, Biological; D012044:Regression Analysis; D020940:Reishi / Q000254:growth & development / Q000378:metabolism*; D014315:Triterpenes / Q000378:metabolism*
chemical_list: D003470:Culture Media; D004365:Drugs, Chinese Herbal; D014315:Triterpenes; C534033:ganoderic acid Me