Isolati on of Cd Removal Bacteria from Beira Lake, Colombo, Sri Lanka and Evaluati on of their Capacity in Cadmium Removal

Abstract

Cadmium (Cd), a heavy metal, is reported to be exceeding its consumable levels in the environment due to several anthropogenic acti viti es. Cd contaminati on thus challenges the ecosystems and human health due to its persistence and toxicity. It is confi rmed that bioaccumulati on of Cd leads to cancers and osteoporosis. Hence, concerning their eco-friendliness and cost-eff ecti veness, urgent remediati on methods are needed for clearing the issue of Cd-contaminated water and soil. The present study deals with three Cd-resistant bacterial strains isolated from Beira Lake, Sri Lanka; and named as TTCB, TTGB, and TTPB. The isolated strains are found to have performed remarkably eff ecti vely with the Cd removal effi ciencies of 97.4%, 97.5%, and 97.5%, respecti vely, as determined by an atomic absorpti on spectrophotometric assay. Their highest eff ecti veness was found at temperatures ranging from 30°C to 40°C and in a pH range of 6 to 7. Moreover, the isolated strains indicated higher Minimal Inhibitory Concentrati ons (1200 – 2000 ppm), confi rming a strong tolerance to Cd. It is highlighted that the MIC levels of the isolated strains are remarkable in comparison with the model organisms as Bacillus cereus ATCC 10876 and Pseudomonas aeruginosa ATCC (300 – 700 ppm). The resulti ng potenti ality of the isolated strains has suggested a promising bioremediati on applicati on for Cd- contaminated environments, off ering a valuable soluti on to address this pressing environmental issue.