ISOLATION, CHARACTERIZATION AND FORMULATION OF ANTAGONISTIC BACTERIA AGAINST FUNGAL PLANT PATHOGENS

Abstract

Concerns regarding food safety and the environment have led to reduced use ofagrochemicals and the development of sustainable agriculture. In this context,biological control of fungal plant pathogens can improve global food availability,one of the three pillars of food security, by reducing crop losses, particularly forlow-income farmers. Antagonistic bacteria are common soil inhabitants withpotential to be developed into biofungicides for the management of fungal plantpathogens. In this study, antagonistic bacterium was isolated from the commercialcompost from a Resen factory for compost and screened for its growth inhibition offungal pathogens in laboratory tests. The zone of inhibition (mm) was recorded bymeasuring the distance between the edges of the growing mycelium and theantagonistic bacterium. Five replications were maintained for each isolate. Basedon phenotypic characteristics, biochemical tests, and sequence analysis of 16SrRNA, the antagonistic bacterium was identified as Paenibacillus alvei (strain DZ-3). The bacterium suppressed the growth of all five tested fungal plant pathogens(Fusarium oxysporum, Rhizoctonia solani, Alternaria alternata, Botrytis cinereaand Plasmopara viticola) in in vitro conditions over. The survival of antagonisticbacterium in peat and talc formulations decreased time at room temperature, butthe populations remained above 108 CFU/g during the 180-day storage period. Thisstudy suggests that this bacterium can be developed and formulated asbiofungicides for minimizing the crop losses caused by fungal plant pathogens anddiseases caused by them.