Antagonistic Test of Endophytic Bacterial Isolates from the Mangrove Plant Lumnitzera littorea Jack. Voight and Their Potential as a Biocontrol Agent Against Plant Pathogenic Fungi

Abstract

 Endophytic bacteria are bacteria that live in plant tissues and are capable of producing antifungal metabolites. This research aims to identify endophytic bacterial isolates from the plant L. littorea that have the potential as antifungal agents against plant pathogens. Bacterial isolates and pathogenic fungi from the Microbiology Laboratory of Bengkulu University were rejuvenated. Identification was performed using morphology, Gram staining, and biochemical tests. Antifungal testing against Fusarium solani, Curvularia sp., Monillia sp., and Ganoderma boninense was conducted using the isolate culture, pellet, and supernatant of the endophytic bacteria. The volatile test observed the inhibitory ability and changes in fungal hyphal structure due to the antagonistic agent. Out of 25 isolates, 8 were similar to the genus Bacillus, 13 Pseudomonas, 2 Azotobacter, and 2 Micrococcus. A total of 13 isolates showed potential antifungal activity with isolate culture inhibition of 40.96%–62.98%, and pellet and supernatant inhibition of 7.28%–29.50%. These results can form the basis for the development of bacteria-based biocontrol agents as an alternative for controlling plant diseases caused by pathogenic fungi.