Isolation and Characterization of Bacteria from Fly Ash Samples as Bioremediation Agents

Fly ash, a residue generated from coal combustion at coal-fired power plants (CFPPs), presents both economic potential due to its rare earth element (REE) content and environmental risks as a hazardous pollutant. Therefore, an appropriate remediation strategy is required to mitigate its negative impacts while utilizing its valuable components. This study aimed to isolate and characterize bacteria from fly ash samples collected around the Tarahan CFPP, South Lampung, with potential as bioremediation agents for rare earth elements, particularly Yttrium (Y). The research employed an exploratory experimental approach, including sampling, bacterial isolation and cultivation, macroscopic and microscopic characterization, and optimization testing of bacterial tolerance to Yttrium. The results revealed two bacterial isolates (FA1.2 and FA2.2), identified as Gram-negative cocci that do not form spores but are capable of adapting to polluted environments. Optical Density (OD) analysis showed optimal growth at 50 ppm and resistance up to 400 ppm. These findings indicate that both isolates possess strong potential as bioremediation and bio-extraction agents for rare earth elements in fly ash from CFPPs.