Enrichment of Empty Oil Palm Fruit Bunch Biochar with Actinomycetes Bacteria as a Microbial Inoculant Carrier

Background and Objective: Biochar is widely recognized for its porous structure, stability and large surface area, making it a promising carrier for beneficial soil microorganisms. However, limited information exists regarding its efficiency in supporting actinomycete enrichment at varying bacterial densities. This study addressed this gap by evaluating the colonization potential of biochar enriched with actinomycetes. The objective was to determine the optimal bacterial density and dilution level for maximizing colony formation under controlled laboratory conditions. Materials and Methods: The experiment was conducted from July to October 2024 at the Laboratory of Plant Biotechnology, Centre for Research Activities (CRA), Hasanuddin University, using a randomized group design with three replications. Actinomycetes were inoculated onto biochar at three bacterial densities (104, 108 and 1012 CFU/mL) and three dilution levels (105, 106 and 107). Colony observations were recorded weekly for four weeks. Visual colony morphology was documented and environmental conditions (pH, temperature and humidity) were monitored. Data were tabulated and analyzed using ANOVA and significant treatment effects (p