Screening actinomycetes as biological control agents against the Dickeya zeae, causal agent of bacterial heart rot of pineapple

Abstract Bacteria heart rot is one of the devastating bacteria diseases in the pineapple crop. Actinomycetes, a group of bacteria that are renowned for their diverse bioactive compounds and antagonistic properties, have emerged as promising candidates for biological control agents against bacterial heart rot of pineapple. This study is to screen the potential of actinomycetes isolated from few locations in UiTM Jasin Campus through random sampling, to inhibit the growth and development of bacteria causing heart rot in pineapple crop. The research activities involve the isolation, identification, and characterization of actinomycetes strains, assessing their antagonistic activities against the bacterial pathogens associated with heart rot disease. Results from the study showed that certain actinomycetes strains have the capability to inhibit the growth of bacteria pathogen via the bioassay test. Out of five isolates, AC 4 isolate produced the highest inhibition zone. All the isolates have the characteristics that fit actinomycetes. Among the key features of actinomycetes are diverse colony colours (white, cream, yellow, red, black) and textures (powdery, velvety, leathery) and gram-positive. Molecular identification revealed that AC4 isolate belongs to genus Streptomyces. Actinomycetes offer a sustainable and eco-friendly approach to managing bacterial heart rot in pineapple cultivation through biological control. These findings contribute valuable insights for the development of practical strategies for integrated disease management in pineapple crops and provide a foundation for further exploration of actinomycetes-based biocontrol in agriculture.