Characterization of phosphate-solubilizing bacteria isolated from acidic Ultisol soil, South Borneo

Borneo Island is an area crossed by the equator, which is characterized by high rainfall and stable warm temperatures condition. In these condition, the soil experiences advance weathering so that the content of Fe2+ and Al 3+ in the soil is very high. This causes many problems, such as high fixation of P by poisonous Fe and Al so that P elements become unavailable for plant. Plant Growth Promoting Rhizobacteria (PGPR) can support the growth of plants by the Al and Fe chelation mechanism so that the plants are not poisoned by the toxic elements and P nutrients can be available for plants. The purpose of this study was to isolate Phosphate Solubilizing Bacteria (PSB) from acidic ultisol soil. The results showed that among isolated PSB, PL1 isolates and PL2 isolates had the highest value of P solubilizing index. DNA of these 2 potential isolates were extracted and then amplified gDNA showed 1330-1500 bp.