Cultivable Endophytic Fungi Producing Phosphatase of Rhizophora mucronata

Low availability of phosphorus (P) is a major constraint for optimal crop production as in the soil it is mostly present in insoluble form. Therefore, the availability of phosphate in the soil can be improved by the utilization of phosphate-solubilizing microorganisms. The existence of Rhizophora mucronata as the dominant species in the Wanatirta mangrove forest, Kulon Progo is estimated to be inseparable from the role of endophytic fungi that produce important compounds for the growth and development of host plants including production of phosphatase enzyme. This study aimed to determine the diversity of endophytic fungi from R. mucronata root and to evaluate their potential in producing phosphatase enzyme. Isolation of endophytic fungi was conducted by growing the pieces of the root on the Pikovskaya medium containing insoluble phosphate, namely calcium phosphate (Ca 3 (PO 4 ) 2 ). Endophytic fungal isolates were purified on Potato Dextrose Agar medium. The screening test of phosphatase activity was performed to determine the ability of each isolate to produce phosphatase enzymes. The characterization of endophytic fungi isolates was carried out by observing the microscopic and macroscopic appearance of each isolate and then comparing it with the fungi identification book. The results obtained six endophytic fungi isolates of R. mucronata root, namely U2A, T2A, T3B, P2, P3A and P3B. The P2 isolate displayed a phosphatase activity characterized by the formation of a clear zone around the fungi isolate with the phosphate solubility index (PS1) is 2.04. Based on its morphological characteristics, P2 isolate belongs to the genus Penicillium.