木腐菌PDA培养基的改良及应用效果

Improvement and application effect of PDA for wood-decay fungi

摘要:

【背景】 PDA培养基是木腐菌菌种生产阶段的重要培养基，但因缺乏某些木屑成分容易导致产生菌种退化现象，迫切需要进行改良。【目的】 克服普通PDA培养基在木腐菌菌种生产中的缺陷，实现木腐菌菌种的经济高效生产。【方法】 按照木腐菌菌丝生长的营养需求和经济性原则，将农业废弃物鲜菇脚和苹果细枝适当处理后添加到普通PDA培养基，设计改良PDA培养基初筛配方，以香菇(Lentinus edodes) 808和白玉菇(white Hypsizygus marmoreus)菌丝的菌丝生长速率S和菌丝脱氢酶激活率K为参数对初筛配方进行筛选。在初筛基础上进行配方优化，选取菌丝生长速率S、菌丝增重W及菌丝鲜重G为主要评价参数考察优化配方的菌丝培养效果和效益，分析菌丝生长速率S、菌丝增重W、菌丝鲜重G与菌丝脱氢酶激活率K、纤维素酶活力N之间的相关性和差异性，探索菌丝增长与酶活性之间的关联性。【结果】 添加鲜菇脚和苹果细枝来改良的PDA培养基配方初筛结果表明，葡萄糖用量为1%-2%时，添加白玉菇脚和苹果细枝来改良的PDA培养基与添加平菇(Pleurotus ostreatus)脚和苹果细枝来改良的PDA培养基能有效促进菌丝生长并激活菌丝脱氢酶活力，菌丝生长效果良好。在26种改良PDA培养基的优化配方中，配方B11 (枝条液30.0 mL，白玉菇鲜菇脚汁10.0 mL，葡萄糖5.0 mL，马铃薯浸液50.0 mL，水5.0 mL)的香菇菌丝生长效果最好，可使菌丝生长速率增加7%，菌丝增重增加106%，菌丝鲜重增加84%，同时实现葡萄糖用量的减半。配方P16 (枝条液30.0 mL，平菇鲜菇脚汁20.0 mL，葡萄糖5.0 mL，马铃薯浸液40.0 mL，水5.0 mL)的白玉菇菌丝生长效果最好，可使菌丝生长速率增加29%，菌丝增重增加47%，菌丝鲜重增加129%，实现葡萄糖用量减半且马铃薯浸提液节省20%，总体成本降低10%，经济和社会效益突出。配方优化实验各指标参数的差异性与相关性统计分析结果表明，菌丝脱氢酶激活率K、纤维素酶活力N与菌丝生长速率S、菌丝增重W和菌丝鲜重G之间既无显著性差异，也无相关性。【结论】 通过添加鲜菇脚(平菇和白玉菇)和苹果细枝对普通PDA培养基进行适度改良，可有效促进香菇和白玉菇菌丝的生长和增重，效果明显，同时实现葡萄糖和马铃薯浸提液用量的大幅降低，降低生产成本，提高经济和社会效益。菌丝生长与脱氢酶活力、纤维素酶活力之间无相关性。

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.