Impact of plant growth-promoting bacteria on the growth of button mushroom hyphae and control of pathogenic factors under in vitro conditions

The current average yield of button mushrooms is 17 to 20 kilograms per square meter. Increasing this yield to 22 to 27 kilograms per square meter could significantly enhance the economic viability and global competitiveness of mushroom production. Achieving this improvement requires a comprehensive understanding of the microbial dynamics in compost production and the nuanced nutrition of mushrooms, utilizing biological, organic, and chemical enhancers. A recent study utilized nine leading strains of the Pseudomonas genus, six strains of Bacillus subtilis, and five strains of Bacillus thuringiensis to promote growth and biocontrol capabilities. While no significant differences were observed among the strains, all Pseudomonas strains were found to effectively stimulate button mushroom mycelium growth, with strain P8 exhibiting the most pronounced growth-enhancement properties. Additionally, Bacillus subtilis strains S1 and S6 significantly boosted mycelium growth, and Bacillus thuringiensis strains T2, T3, and T5 supported mycelium growth. However, some strains (S2, S5, T1, and T4) inhibited button mushroom growth in certain mediums (PDA/NA + Extract medium). The most notable biocontrol effects were by strain S3 against the Trichoderma and strain S6 against the Mycogone fungus, each inhibiting growth with a maximum colony zone diameter of 20 millimeters, whereas strain T5 showed the least biocontrol effect. Given the beneficial and diverse effects exhibited by the species from the two genera studied, these findings suggest that employing a consortium of these bacteria as a biofertilizer could significantly enhance button mushroom production outcomes.