Exploration and identification of bacteria from bat cave for Pb and Cd heavy metal immobilization using MICP

Abstract

Abstract Heavy metal contamination, particularly by lead (Pb) and cadmium (Cd), poses a serious environmental and health threat due to their toxicity and persistence in ecosystems. Microbially induced carbonate precipitation (MICP) is a promising bioremediation strategy that utilizes ureolytic bacteria to immobilize heavy metals in contaminated environments. This study, entitled “Exploration and Identification of Bacteria from Padayo Bat Cave, Padang for Pb and Cd Heavy Metal Immobilization Using MICP,” was conducted from November 2024 to March 2025 at the Microbiology Research Laboratory, Department of Biology, Andalas University, Padang, and the Environmental Engineering Laboratory, Faculty of Civil Engineering, Universiti Teknologi Malaysia, Johor Bahru, Malaysia. This study aimed to isolate, identify, and characterize bacteria from Padayo Bat Cave, Padang, and evaluate their potential for Pb and Cd immobilization through the MICP process. The study focused on macroscopic, microscopic, and biochemical characterization of bacterial isolates, as well as evaluation of urease activity, calcium carbonate precipitation ability, and heavy metal immobilization potential. Several isolates exhibited ureolytic activity and induced calcium carbonate precipitation, contributing to Pb and Cd immobilization. Among the tested isolates, CWB2 showed the highest immobilization performance at Pb and Cd concentrations of 0.8 g/L and 0.6 g/L, respectively. These findings indicate that indigenous bacteria isolated from bat guano and cave water have potential for heavy metal immobilization through MICP, with variations in precipitation performance depending on bacterial isolates, metal concentrations, and incubation periods.