Bio-fungicidal impact of volatile and non-volatile compounds from Bacillus paramycoides for the management of Trichoderma-induced green mold on mushrooms

Abstract

Worldwide, mycoparasites in mushrooms seriously impair the financial success of commercial mushroom farms. Especially, Trichoderma species cause green mold disease that lowers the production and quality of edible mushrooms. The volatile and non-volatile organic compounds (VOCs) produced by bacteria can significantly impact positively or negatively the morphological characteristics and mycelial growth of fungi. Therefore, this study aimed to evaluate 161 bacterial isolates’ fungicidal potential against Trichoderma spp. such as T. viride, T. harzianum, and T. asperellum. Our results showed that co-cultivation of Bacillus amyloliquefaciens, Aneurinibacillus migulanus, Bacillus paramycoides, and Bacillus isolates 28, 65, and 88 exhibited antagonistic activities against Trichoderma spp. Notably, antagonistic activity of 73.3% was recorded for B. paramycoides against T. viride compared to the control and other species. However, no antagonism was expressed by P. fluorescens, B. clausii, and B. polymyxa against Trichoderma spp. Dose-dependent antibacterial activity was observed in intra- and extracellular crude extract of B. paramycoidesagainst B. subtilis and P. aeruginosa. The bioactive VOCs and non-VOCs produced by B. paramycoides were characterized by GC-MS that may significantly inhibit spore germination of T. viride, T. harzianum, and T. asperellum. Our finding demonstrates how strikingly species-dependent impacts of bacteria discourage mycelial growth, and how bacterial volatile organic compounds (VOCs) can do just that. From the results, it can be apparent that B. paramycoides could be used as bio-fungicidal against Trichoderma spp. induced infections during mushroom farming.