Potential of thermophilic bacteria as microbial inoculant for commercial scale white button mushroom ( Agaricus bisporus ) compost production

Abstract

Thermophilic bacteria (9), isolated from button mushroom (Agaricus bisporus) compost samples, were evaluated for temperature requirement, extracellular lignocellulolytic enzymes activity assay and potential for white button mushroom compost production. Optimum growth in different bacteria was between 43-55°C. Highest activity of exoglucanase and endoglucanase was recorded in Staphylococcus sp., while that of β-glucosidase in Bacillus brevis and B. megaterium, and xylanase as well as laccase in B. stearothermophilus. Staphylococcus sp. also exhibited second best activity of xylanase. Compost prepared with Staphylococcus sp. exhibited highest colony forming units of bacteria, numbers of mushroom pinheads and mushroom yield. Compost prepared with extraneous inoculation of two potential bacteria (Staphylococcus sp. and B. megaterium-I) at commercial scale did not show much variation in physico-chemical properties, however, compost prepared with Staphylococcus sp. supported early mushroom harvest by 1.5 - 2.0 days and significantly higher mushroom yield in two cultivation trials. Thus Staphylococcus sp. has potential to convert agro wastes into selective and productive compost for white button mushroom cultivation.