Characterization phosphate-solubilizing marine actinobacteria associated with Sargassum Sp from Menjangan kecil island, Indonesia

Phosphorus plays a crucial significant role in all life forms. Microbes have the ability to convert several forms of phosphorus into dissolved forms, so that they can also be used in the phosphorus cycle process. The aim of this research were to explore, screen, phenetic and molecular identify the phosphobacteria naturally colonized and associated with Sargassum sp. from the Menjangan Kecil Island, Karimunjawa. Total of 23 bacterial isolates associated with Sargassum sp. were screened. All isolates obtained were tested for their ability in phosphate dissolution activity in Pikovskaya agar medium. Three different isolates showed the largest dissolution activity around bacterial colonies selected for quantitative estimation of phosphate solubilization. The next screening was to choose one candidate isolate based on its highest ability in dissolving phosphate and then identifying its identity based on phenotypic character and 16S rRNA gene. Quantitative estimation of phosphate solubilization PSB isolates MBS3R was 149,32 μg P ml-1 was analyzed for 120 hours of incubation at room temperature. MBS3R isolate is a strain of Microbacterium sp, which is taxonomically included in the class of Actinobacteria, genus Microbacterium.