Bioextraction Dynamics of Potassium from Feldspar by Heterotrophic Microorganisms Isolated from Ceramic and Rhizospheric Soil

Abstract

Bioleaching of potassium from feldspar was optimized for five fungal and two bacterial isolates for carbon, nitrogen, agitation, pH and incubation time. Fungal isolates SDSR and SDS3 and bacterial isolate SDS1 released 34, 42 and 28 ppm K in sucrose-amended medium, respectively. Isolate SDS3 took 10 days for the highest K solubilization, whereas SDSR required 15 days under 150 rpm shaking condition. The pH of medium was found to decrease from 7.0 to 2.05 after the growth of the organisms. High-performance liquid chromatography analysis of the filtrate showed the presence of citric, tartaric and maleic acid, which could be responsible for the solubilization of potassium.