SOLUBILIZAÇÃO BIOLOGICA DE POTÁSSIO POR Burkholderia cepacia A PARTIR DE RESÍDUOS DE ROCHAS DO ESTADO DO RIO DE JANEIRO

Abstract

The biological solubilization of potassium by the bacterial strain Burkholderia cepacia ATCC 25416 was investigated through in vitro assays  using rock residues originationg  from the State of Rio de Janeiro. Initially, qualitative plate assays were performed to evaluate the potassium biosolubilization potential of the strain, based on halo formation. Subsequently, with the objective of optimizing potassium bioavailability, a 2² factorial design was conducted, considering pulp density and agitation as independent variables over a 20-day incubation period. Halo formation was observed on plates containing the different rock residues, indicating the production of organic acids, with solubilization indices of 2.31 and 2.47 for the Magé and Itaguaí residues, respectively. In the biosolubilization assays, mean potassium extractions of 1155 mg/kg (Magé) and 1210 mg/kg (Itaguaí) were obtained under the conditions of lower pulp density and higher agitation (150 rpm). Statistical analysis corroborated the experimental results, demonstrating that lower pulp density combined with higher agitation exerted a significant positive effect on potassium release from the rock residues.