Bioremediation of cadmium polluted water using a novel indigenous bacteria Bacillus albus Isolated from Tempe Lake, Indonesia

Cadmium (Cd) pollution poses a significant hazard to the ecosystem due to its toxicity and non-biodegradability. This research used novel indigenous bacteria widely isolated from Tempe Lake in South Sulawesi, Indonesia, for cadmium reduction. Bacterial identification was performed using the 16S rDNA method. Measurement of Cd reduction was performed using atomic absorption spectrometry (AAS). Results revealed that, in Tempe Lake, heavy metal Cd values surpassed the minimum water quality level limits. Isolation of indigenous bacteria from the contaminated lake resulted in a total of six isolates, i.e., two isolates of rod-shaped Gram-positive bacteria and four isolates of cocci-shaped Gram-negative bacteria. These naturally occurring microorganisms were able to decrease Cd concentration in the bacterial medium by up to 68.93%. Based on their physiological profile, these native bacteria belonged to the genus Bacillus. According to the sequencing data that were analyzed using neighbor-joining phylogenetic analysis, the isolate was identified as Bacillus albus with 99% similarity. In conclusion, the native B. albus bacteria of Tempe Lake could be suggested as a potential bioremediation agent for heavy metals, specifically Cd, in contaminated water. However, this study is limited by the scope of bacterial isolates and the controlled laboratory conditions. Further research should focus on field applications and the long-term stability of the bioremediation process.