Abstract
Abstract
Aim/Background
Urbanization and anthropogenic activities have intensified heavy metal contamination, with cadmium (Cd) and lead (Pb) posing significant environmental and health risks due to their persistence, bioaccumulation, and toxicity. This study aimed to isolate and characterize Cd- and Pb-resistant bacteria from urban soils near a petrol pump in Ghatkopar (West), Mumbai—a high-traffic area with poor air quality and elevated particulate pollution.
Methods
Soil samples were processed to isolate Cd- and Pb-resistant bacteria. Representative isolates were identified using 16S rRNA gene sequencing, and minimum inhibitory concentration (MIC) assays were performed to determine metal tolerance levels.
Results
Seven Cd-resistant and eight Pb-resistant colonies were obtained, with three isolates—C5 (Pb-resistant), C12 (Cd-resistant), and C14 (Cd-resistant)—selected for further analysis. 16S rRNA gene sequencing identified these isolates as Paenalcaligenes faecalis (C5, GenBank OQ880494), Achromobacter xylosoxidans (C12, OQ880499), and Pseudomonas aeruginosa (C14, OQ880500). MIC assays showed metal tolerance of 900 ppm Pb for C5, and 400 ppm and 700 ppm Cd for C12 and C14, respectively.
Conclusion
These results demonstrate substantial heavy metal resistance in indigenous bacteria from petroleum-contaminated urban soils, highlighting their potential for bioremediation of Cd- and Pb-polluted environments. The study addresses a key knowledge gap regarding metal-resistant microbial communities in Mumbai and identifies the Ghatkopar petrol pump area as a hotspot for heavy metal accumulation, providing a basis for developing localized, eco-friendly bioremediation strategies.

Key words: cadmium resistance, lead resistance, bioremediation, minimum inhibitory concentration, 16S rRNA sequencing, urban soil pollution