Testing some wild Bacillus spp. strains as potential biocontrol agents

Abstract

The present investigation follows the study of twenty-four Bacillus spp. strains isolated from different samples (compost, municipal waste, crops waste, silage, forest soil, rhizosphere soil, poultry litter, cattle dung and rotting wood) collected from different areas from Galați region, Romania and the assessment of their potential as biocontrol agents against molds. The obtained results demonstrated that the tested indicator fungal strains, Penicillium expansum MIUG M11, Geotrichum candidum MIUG M63, Aspergillus glaucus MIUG M61 and Fusarium graminearum MIUG M59 were sensitive to varying degrees towards the Bacillus spp. action, with growth inhibition degrees ranging from 56.75% to 100%. Four Bacillus spp. isolates possess the ability to produce extracellular chitinase, which could be also used for the control of fungi and insects. By using the radial diffusion method, a hydrolysis zone of
colloidal chitin between 27.0-34.5 mm was highlighted. The selected Bacillus spp. strains can be promising antifungal agents for pest control in agriculture and food industry.