Improving the Fermentation Production of the Individual Key Triterpene Ganoderic Acid Me by the Medicinal Fungus Ganoderma lucidum in Submerged Culture

Gao-Qiang Liu,Qin-Lu Lin,Wen-Jun Han,Xiao-Ling Wang

doi:10.3390/molecules171112575

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·L−1 for glucose, peptone, culture time values of 44.4 g·L−1, 5.0 g·L−1, 437.1 h, respectively, and a maximum GA-Me yield of 12.4 mg·L−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·L−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.

Highlights

Ganoderma lucidum (Leyss. ex Fr.) Karst (“Ling-zhi” in Chinese and “Reishi” in Japanese) is a famous medicinal mushroom that has been used as a traditional medicine for a long time in Asia [1].The potential medicinal value and wide acceptability of this edible mushroom have attracted intense interest in the search for its biologically active substances during the last 30 years [2,3,4]
The mycelial dry weight (DW) reached 13.1 g·L−1, and a 5.4 mg·L−1 of GA-Me production yield was obtained in G. lucidum cultures, of which, 2.8 mg·L−1 was obtained in the mycelia and 2.6 mg·L−1 was collected from the fermented supernatant
Glucose, peptone and culture time were the key factors for GA production [17]

Summary

Introduction

Ganoderma lucidum (Leyss. ex Fr.) Karst (“Ling-zhi” in Chinese and “Reishi” in Japanese) is a famous medicinal mushroom that has been used as a traditional medicine for a long time in Asia [1].The potential medicinal value and wide acceptability of this edible mushroom have attracted intense interest in the search for its biologically active substances during the last 30 years [2,3,4]. Some of the potent biologically active compounds that have been shown to possess diverse and potentially significant pharmacological activities are the bitter triterpenes (especially ganoderic acids, GAs) [7,8,9,10]. Since the first discovery of ganoderic acids A and B (GA-A, GA-B), over 150 types of triterpenes have been isolated from various parts of G. lucidum [11], among which GA-Me has received considerable attention due to its conspicuous pharmacological properties, especially anticancer activity. It was found that GA-Me depressed the viability of tumor cells at much lower concentrations than against normal cells [14], making it an effective potential therapeutic drug for the prevention and treatment of tumors in the clinic. GA-Me was demonstrated to inhibit cholesterol synthesis [10,15]

Objectives

Results

Conclusion