Screening and bioassay of halotolerant phosphate solubilizing bacteria using rice (Oryza sativa L.) on salinity media

Some beneficial microbes have the ability to tolerate salinity stress conditions to obtain superior isolates of halo tolerant phosphate solubilizing bacteria (PSB) and determine the ability of PSB isolates to increase the growth of rice seedlings. The research was carried out at the Laboratory and Greenhouse of the Department of Soil Science and Land Resources, Faculty Agriculture, Universitas Padjadjaran. In this study, halotolerant PSB were isolated from saline soil with salinity 4 dS/m and grown in Pikovskaya medium. The results showed that a superior isolate of phosphate solubilizing bacteria had been obtained from saline soil which were capable of producing phytohormones, phosphatase enzymes and organic acids. Three superior isolates PSB 1, PSB 3, and PSB 6 produced phosphatase enzymes (3.508 mu g pNP/g/h, 3.307 mu g pNP/g/h, and 3.257 pNP/g/h), growth hormone IAA (4.611 ppm, 4.913 ppm, and 3.819 ppm), and organic acids (citric, acetic, oxalic, lactic, malic and ascorbic). These isolates could form biofilms . Inoculation of PSB isolates were able to increase root length by 45.01%, 37.54%, and 32.65%. The isolate was also able to increase plant height by 28.58%, 43.77%, and 62.69%.The provision selected PSB isolates, could increase the growth of rice plants and have the potential to be developed as biofertlizer to increase the productivity of rice plants in saline soil.