Optimizing the fermentation of the biological inoculant of a fairy ring antagonist

The aim of this study was to optimize the fermentation conditions for obtaining the biological inoculant of an antagonist of the fairy ring mushroom Lepiota brunneoincarnata. Aspergillus flavus CP01 is a pathogen of the fairy ring mushroom, and we optimized its liquid and solid fermentation conditions. We screened for the best liquid fermentation conditions of the antagonist in terms of medium type, fermentation time, temperature, and initial pH using the single-factor method. We also screened for the optimal solid fermentation conditions of the target host fungus, viz., L. brunneoincarnata, in terms of training material and additional nutrition type, fermentation time, and temperature using the single-factor method. Results showed that the optimal growth medium of A. flavus was potato dextrose broth (PDB), which achieved the maximum dry weight of mycelial bead, while the medium type ensuring the maximum number of effective bacteria and the best antibacterial effect was corn stalk leach liquor (CSE) with an optimal initial pH of 5. The optimal liquid fermentation conditions were identified as 30 ℃ and 5 days. The optimal medium type was counteract-eutrophication straw powder by extraction as training material and corn stalk leach liquor at 1∶50 as additional nutrition type for maximum spore yield. The optimal solid fermentation conditions were identified as 33 ℃ and 9 days. These optimized parameters establish a technical basis for the development of an antibiological inoculant of fairy rings.