Abstract:[Background] Grifola frondosa showed degenerated characteristics due to long-term subculture. [Objective] To restore the biological activity and characteristics of G. frondosa through rejuvenation method, and to acquire strains possessing improved vitality and genetic stability through mutagenesis by high efficient apparatus. [Methods] Hyphae tip isolation method was utilized for rejuvenation of the strains cultivated in PDA enriched medium and PDA-chestnut shell medium respectively. Rejuvenated strain P-2 regained its biological activity and properties. To further improve its production performance, P-2 was subjected to ARTP mutagenesis, and a mutant b-35 with promoted performance and high genetic stability was obtained finally. [Results] The dry weight of mycelium and polysaccharide content of the strain P-2 were 1.18% and 19.01%, and the growth rates were 35.17% and 35.11% respectively compared with that of the original strain. Cultivation of P-2 in fermentation tank indicated that the fermentation cycle was shortened to 32 h from 48 h, showing significant improvement of fermentation activity and efficiency. Mycelium dry weight and polysaccharide content of the mutant b-35 reached 1.56% and 25.07%, 40.15% and 39.33% higher than that of P-2. [Conclusion] ARTP mutagenesis method was proved to be an important way in breeding of high yield Grifola frondosa because it is easily operated, pollution-free and efficient.
