The aim of this study is to search for potential Bacillus spp. that can suppress the infection of Trichoderma sp. in Shiitaki mushroom (Lentinus edodes) and oyster mushroom (Pleurotus sajor-caju). Preliminary screening of 30 isolates of Bacillus spp. was performed against the green mold, Trichoderma sp., one of the pathogens of several mushroom cultivation. All bacilli except the commercial product, Plaikaow TM (B. subtilis PKTM) were isolated from infected and non infected mushrooms with Trichoderma sp. Antifungal efficiency was examined by agar diffusion and dual culture assay. Microscopic study revealed that the bacilli caused abnormalities in mycelium, such as cytolysis, vacuole formation, cell-shrink and cell-size reduction. API 50 CHB was used to identify the species of 5 isolates and 4 isolates were found to be B. subtilis (designated as Bs 02-SU2, Bs 05-SU3, Bs 07-SU4 and Bs 09-SU5) while another species was B. licheniformis (Bl 01-SU1). For in vivo test in mushroom house, bacterial cell suspensions from 24 hr. incubation time, pH 7 at 37 0C, containing 106 cell/ml of the 5 selected isolates were injected into the spawn cultivated mushrooms and followed by 106 spore/ml of Trichoderma sp. 2 days later. Trichoderma sp. infected-mushrooms were counted twice a week, for a period of 6 weeks. It was found that the percentage of green mold infection by Bl 01-SU1 on L. edodes and P.sajor- caju was 58.23 and 80, respectively. Its efficacy was equivalent to Bs PKTM (P > 0.05) but was significantly different (P<0.05) from the rest of other bacterial isolates. In addition, all tested bacteria exhibited significantly higher suppression for Trichoderma sp. infected P. sajor-caju than those infected L. edodes.
Keywords: microbial control, microbial antagonism, Bacillus, green mold, Trichoderma, mushroom, Lentinus edodes, Pleurotus sajor-caju
Corresponding author: E-mail: titiya@su.ac.th
Chittihunsa, T. ., Bangeekhan, E. ., Wongsamitkul, N. ., & Subsomboon, T. . (2007). SCREENING OF Bacillus spp. SUPPRESING THE INFECTION OF Trichoderma sp. IN MUSHROOM CULTIVATION. CURRENT APPLIED SCIENCE AND TECHNOLOGY, 19-27.
