Antifungal, growth-promoting, and lignocellulose degrading-bacteria from compost and casing soil of button mushroom (Agaricus bisporus)

Abstract

Eleven dominant mesophilic and thermophilic bacteria were identified from the phase-1 compost and casing of button mushroom (Agaricus bisporus). During phase 1 (at 45–48 °C), Bacillus subtilis (BSB1, BSB3, BSB5, and BSB13), Paenibacillus polymyxa (PPB6), Bacillus sp. (BB7), B. cereus (BCB8 and BCB12), and Acinetobacter johnsonii (AJB15/B) were identified as useful bacterial species by 16S rRNA sequencing. Whereas, in casing soil (at 22–25 °C) Alcaligenes faecalis (AFB11) and Pseudomonas aeruginosa (PAB16/P) were identified as useful mesophiles. PAB16/P showed the strongest antagonistic activities against M. perniciosa (wet bubble disease) with the highest mycelial growth inhibition (91.89%), followed by BB-7 (76.39%). The other isolates, BSB1, BSB3, BSB5, PPB6, BCB8, and BSB13, also inhibited the growth of M. perniciosa by 61.11 to 72.55%. The degradation of wheat straw via six microbe complexes (MC-1 to MC-6) was monitored based on CO₂ release. The highest CO₂ release (174666.70 ppm) was recorded in MC-3 (a combination of PAB16/P, AJB15/B, AFB11, and BSB5) compared with the lowest in control (43166.60 ppm). Compost inoculated with MC-3 produced the highest crop yield (16.20 kg/100 kg substrate) whereas lowest in control (12.84 kg/100 kg substrate). MC-3 may be recommended for button mushroom compost, to manage wet bubble disease and increase crop yield.