Abstract

Phosphorus is one of the major bio elements limiting agricultural production. About 95 to 99% phosphorus in agricultural soil is unavailable form for plant growth. Phosphate solubilizing microorganisms can increase soil phosphate availability. This study was aimed to identify and evaluate phosphate solubilizing fungi from Teff rhizosphere soil. Fungi were identified using lactophenol cotton blue staining confirmation and Biolog Microstation identification system. Fungi isolates were screened and transferred to biolog universal yeast agar media. Pure yeast cells and filamentous fungi were suspended in sterile water and filamentous fungi (FF) inoculum fluid at 49±2 and 75±2 turbidity measured by biolog turbidimeter, respectively. 100 μL transferred from each suspension into 96 wells of the biolog yeast microplate and filamentous fungi microplate tagged with different carbon source and incubated at 26°C for 24 to 72 h and read by micro station at a single wavelength of 590 nm, results were recorded and processed for identification by micro log3 software ver. 4.20.05. Biolog microstation read 24 fungi species. Filamentous fungi ≤0.5 similarity index (62.5%), yeast 0.5 similarity index (25%), yeast ≤0.5 similarity index (12.5%). The identified fungi were tested for phosphate solubilization by the Pikovskaya’s agar (PVK) selective media. Seven species were positive in phosphate solubilizing ability: Trichosporon beigelii B, Rhodotrula aurantiaca A, Cryptococcus luteolus, Zygoascus hellenicus, Penicillium purpurogenum var. rubrisclerotium, Neosartorya fisheri var. fischeri, and Candida montana. At 15 days incubation, T. beigelii B and R. aurantiaca A was able to solubilize phosphate with solubilizing index of 5.3 and 2.6, respectively. T. beigelii B, were superior in phosphate solubilization. Therefore, these species can be candidated and exploited after further evaluation as biofertilizers for agriculture productivity.

Key words: Biolog Microorganisms, micro station, phosphorus, rhizospher, soil, solubilization, Teff.