Phosphate Solubilizing Yeast Isolated and Characterized from Teff Rhizosphere Soil Collected from Gojam; Ethiopia

Abstract

Phosphorous is an essential macronutrient for plant growth and development. About 95-99% present in soil insoluble form. Phosphate solubilizing microorganisms can increase soil phosphate solubility and availability. This study was aimed to identify and evaluate phosphate solubilizing yeast from Teff rhizosphere soil. Yeasts were identified using Biolog Micro station identification system. Yeast isolates were screened and transferred to biolog universal yeast agar media. Pure yeast cells were suspended in sterile water at 49±2 turbidity measured by biolog turbidimeter. 100μ- L transferred from each suspension into 96 wells of the biology yeast micro Plate tagged with different carbon source and incubated at 26°C for 24 to 72h and read by micro station at a single wavelength of 590nm, results were recorded and processed for identification by micro log3 software ver. 4.20.05. Above 0.5 similarities index value is acceptable species identification. Therefore biolog microstations identify nine yeast species with full species identity. The identified yeasts were tested for phosphate solubilization by the Pikovskaya’s agar (PVK) selective media. Nine yeast species were positive in phosphate solubilizing ability. Phichia norvegensis, Cryptococcus albidus var aerius, Candida etchellsii, Cryptococcus albidus var albidus, Rhodotrula aurantiacaA, Rhodotorula aurantiaca B, Cryptococcus luteolus, Cryptococcus albidus var diffluens, Cryptococcus terreus A. At 15days incubation their phosphate solubilizing index (PSI) ranges 1.72-3.35. Phichia norvegensis and Cryptococcus albidus var aerius were superior in phosphate solubilization 3.35 and 3.2 SPI respectively. Therefore these species can be candidated and exploited after further evaluation as bio fertilizers for teff productivity.