BIOCONTROL POTENTIAL OF BACILLUS PARAMYCOIDES FOR MANAGEMENT OF GREEN MOLD OF AGARICUS BISPORUS CAUSED BY TRICHODERMA SPP.

Trichoderma spp. are significant fungal contaminants causing green mold in Agaricus bisporus, which reduce yield and quality. This study, conducted at the Prof. TNA Innovation Research Centre (TNAIRC), Jiblakpally, Greater Hyderabad from 2022 to 2024, aimed to identify an effective biocontrol agent for managing Trichoderma-induced green mold. In dual culture assay, out of 25 bacterial treatments (19 isolated from rhizospheric soil and six from the culture bank of TNAIRC), 11 cultures inhibited growth of at least one species of Trichoderma (2.7-73.3%). These 11 cultures reduced dry biomass of test fungi also ranging from 10.1 to 82.6%. Out of top 5 promising cultures were chosen for VOC production and field efficacy. In VOC studies, Bacillus isolate V37 was most effective in inhibiting spore germination of Trichoderma spp. (0.3-8.7%). In field efficacy studies, bags treated with Bacillus isolate V37 showed lowest incidence of green mold (2.4-4.6%), than control (16-25%). Isolate V37 was identified as Bacillus paramycoides PP757924.The intracellular extract of B. paramycoides demonstrated the highest antifungal activity against T. asperellum (21.69 mm), while the extracellular extract was most effective against T. viride (22.51 mm) and T. harzianum (19.96 mm). GC-MS analysis of intra- and extracellular extracts of B. paramycoides showed 19 and 27 secondary metabolites, respectively. As far as we are aware, this is the first publication to show that B. paramycoides has the ability to biocontrol Trichoderma spp.