Isolation and characterization of sp. strain BC01 from soil displaying potent antagonistic activity against plant and fish pathogenic fungi and bacteria.

Fungal and bacterial pathogens infect a diverse range of hosts including various plant and animal species. Fungal and bacterial diseases, especially of plants and aquatic animals, such as fish, lead to significant damage to crops and aquaculture, respectively, worldwide. The present study was conducted to isolate and characterize potent strains with significant antagonistic activity against the major plant and fish pathogenic fungi and bacteria. We randomly collected 22 isolates of from the soil, rhizosphere, and sediment from different parts of Bangladesh. Initial characterization, based on antagonistic activity on the culture plate, resulted in the selection of four gram-positive sp. isolates. Among these, the isolate BC01, obtained from soil demonstrated the highest broad-spectrum anti-bacterial and anti-fungal activities. We confirmed the genus of BC01 to be by morphological and biochemical tests as well as using molecular data analysis tools, including the study of 16s rDNA, phylogenetic relationship, and evolutionary divergence scores. The isolate significantly inhibited the mycelial growth of the plant pathogen, and fish pathogen, . The anti-bacterial effect of the isolate was also evaluated against spp. and spp., the two deadliest plant pathogens, and , , and , three major fish pathogens that are primarily responsible for global aquaculture loss. The results of the present study could pave the way for developing potent drugs to combat microbial infection of plants and fish.