Isolation of a New Mexican Strain ofBacillus subtiliswith Antifungal and Antibacterial Activities
Although several strains ofB. subtiliswith antifungal activity have been isolated worldwide, to date there are no published reports regarding the isolation of a nativeB. subtilisstrain from strawberry plants in Mexico. A native bacterium (Bacillus subtilis21) demonstratedin vitroantagonistic activity against different plant pathogenic fungi. Under greenhouse conditions, it was shown that plants infected withRhizoctonia solaniandFusarium verticillioidesand treated withB. subtilis21 produced augment in the number of leaves per plant and an increment in the length of healthy leaves in comparison with untreated plants. In addition,B. subtilis21 showed activity against pathogenic bacteria. Secreted proteins byB. subtilis21 were studied, detecting the presence of proteases and bacteriocin-like inhibitor substances that could be implicated in its antagonistic activity. Chitinases and zwittermicin production could not be detected. Then,B. subtilis21 could potentially be used to control phytopathogenic fungi that infect strawberry plants.