Seleksi Bakteri Pemfiksasi Nitrogen Dari Rhizosfir Berbagai Tanaman Sebagai Kandidat Kultur Biofertilizer

Ten Isolates nitrogen fixing have been isolated and selected from rhizosphere of some plants. The isolates showed the Azospirillum characters, such as demonstrated pink to deep red colony on Casteres medium and appeared motile Gram negative polymorph rod cells. Those nitrogen fixing bacteria were isolate of GJR2, TKM3a, SW3.1, PRD2, BM1, KK1, JG2.2a, KC1, GN2, PD1.3a. All isolate performed reducing acetylene activity. The assay of nitrogen fixation effectivity that was carried out on maize plant growth showed that, the different plants influenced the ability of Azospirillum in fixing nitrogen. The isolate Azospirillum PRD2 had the best activity on plant dry weight 195mg, plant root length 9,5 cm, and plant height 22,75 cm. Therefore, isolate PRD2 could be designed as an inoculant in formulating biofertilizer cultur