Bioprospecting Study of Plant Growth Promoting Rhizospheric Bacteria from Oil Palm Plantation as Biological Control Agent of Ganoderma boninense

Background and Objective: The prioritisation of oil palm studies involves the exploration of novel bacterial isolates as possible agents for suppressing Ganoderma boninense. The objective of this study was to evaluate and characterise the potential of rhizospheric bacteria, obtained from the rhizosphere of oil palm plants, in terms of their ability to demonstrate anti-Ganoderma activity. Materials and Methods: The study began by employing a dual culture technique to select hostile bacteria. Qualitative detection was performed to assess the antifungal activity, as well as the synthesis of chitinase and glucanase, from certain isolates. The candidate strains were molecularly identified using 16S-rRNA ribosomal primers, specifically the 27F and 1492R primers. Results: The findings of the study indicated that the governmental plantation exhibited the highest ratio between diazotroph and indigenous bacterial populations in comparison to the other sites. Out of a pool of ninety bacterial isolates, a subset of twenty-one isolates demonstrated the ability to impede the development of G. boninense, as determined using a dual culture experiment. Twenty-one bacterial strains were found to exhibit antifungal activity. Nine possible bacteria were found based on the sequence analysis. These bacteria include Burkholderia territorii (RK2, RP2, RP3, RP5), Burkholderia stagnalis (RK3), Burkholderia cenocepacia (RP1), Serratia marcescens (RP13) and Rhizobium multihospitium (RU4). Conclusion: The findings of the study revealed that a significant proportion of the bacterial population exhibited the ability to perform nitrogen fixation, indole-3-acetic acid (IAA) production and phosphate solubilization. However, it is worth noting that Rhizobium multihospitium RU4 did not demonstrate the capacity for phosphate solubilization, while B. territory RK2 did not exhibit IAA production.