Improvement and application effect of PDA for wood-decay fungi

Abstract:

[Background] PDA is widely used in the production of wood-decay fungi, while the lack of wood components can easily lead to the degradation of the fungal strains. Therefore, it is urgent to improve the formula of PDA. [Objective] To overcome the shortcomings of routine PDA in the production of wood-decay fungi and achieve efficient and economical production. [Methods] According to the nutrient requirements of mycelial growth and the principle of saving costs, we treated agricultural wastes such as fresh mushroom stem residues and apple plant twigs and then supplemented them into routine PDA to design improved PDA. The formulas of improved PDA were screened with the mycelial growth rate (S) and dehydrogenase activity (K) of Lentinus edodes 808 and white Hypsizygus marmoreus as indicators. Furthermore, the formula of improved PDA was optimized, and the mycelial growth rate (S), mycelial weight increase (W), and mycelial fresh weight (G) were determined to evaluate the mycelial culture effect and benefit of the optimized formula of improved PDA. The correlations and differences of S, W, and G with K and cellulase activity (N) were analyzed to explore the correlation between mycelial growth and enzyme activity. [Results] The improved PDA formula with 1%-2% glucose, stem residues of white H. marmoreus or Pleurotus ostreatus, and apple plant twigs improved S and K. Among the 26 optimized formulas of improved PDA, B11 (twig extract 30 mL, fresh white H. marmoreus stem residue extract 10.0 mL, glucose 5.0 mL, potato extract 50.0 mL, and water 5.0 mL) demonstrated the best performance in improving the mycelial growth of L. edodes 808, increasing the S, W, and G by 7%, 106%, and 84%, respectively, while halving the glucose usage. The formula P16 (twig extract 30 mL, fresh P leurotus ostreatus stem residue extract 20.0 mL, glucose 5.0 mL, potato extract 40.0 mL, and water 5.0 mL) showed the best performance in improving the mycelial growth of white H. marmoreus, increasing the S, W, and G by 29%, 47%, and 129%, respectively. It not only decreased the glucose application by 50% and potato extract application by 20% but also reduced the overall costs by 10%, with outstanding economic and social benefits. There was no significant difference or correlation of K and N with S, W, and G. [Conclusion] Adding fresh mushroom stem residues (P. ostreatus or white H. marmoreus) and apple plant twigs to PDA can improve the mycelial growth and weight of L. edodes 808 and white H. marmoreus. Moreover, it can significantly reduce the usage of glucose and potato extract, decrease costs, and improve economic and social benefits. The mycelial growth showcases no correlation with dehydrogenase or cellulase activity.