Isolation of Bacteriophages and Their Potential as a new Biological Weapon for Controlling Bacterial Disease of Rice in Bangladesh

Abstract

Rice bacterial diseases are one of the major hindrances to achieving crop production across the world, particularly in Asian countries. Bacterial brown stripe (BBS) caused by Acidovorax oryzae (Ao) is one the major diseases of rice responsible for high economic losses. To combat the diseases, this study aimed to isolate and characterize lytic phages infecting Ao, which would serve as potential biological agents for the management of BBS. In this regard, three lytic bacteriophages were isolated from diseased rice leaves in Bangladesh. In this study, the 10 bacterial strains of Ao were identified based on 16S gene sequence analyses, which were screened with their respective phages isolated in this study. Phage AP-1 infected 6 strains of Ao bacteria out of 10 with the most increased titer of plaque in AP-3. All phages showed different titer ranging from 1.19x1010-3.28x1010 for Ao phages. In the host exopolysaccharide production, the Ao phage AP-3 had the highest inhibition of biofilm formation of strains TNGAo-01 of Ao bacteria but the phage AP-2 inhibited significantly by 48.08% as compared to control. Interestingly, all the phages used behaved differently with regard to each of the experiments conducted. These results suggest that all the phages need to be combined in a cocktail to serve as efficient biological control agents in the control of bacterial brown stripe disease caused by A. oryzae in rice.

J. of Sci. and Tech. Res. 4(1): 173-182, 2022