Lettuce (Lactuca sativa L.) is widely cultivated under both organic and inorganic farming systems. The extensive use of agrochemical inputs in inorganic cultivation may increase cadmium (Cd) accumulation in agricultural soils, posing environmental and food safety risks. Endophytic bacteria are known for their ability to tolerate heavy metals and produce extracellular enzymes with potential applications in bioremediation. This study aimed to characterize endophytic bacteria isolated from organic and inorganic lettuce leaves and evaluate their cadmium tolerance and amylase activity. Endophytic bacteria were isolated on Nutrient Agar (NA), followed by morphological characterization and Gram staining. Cadmium tolerance was evaluated at 0, 25, 50, and 100 ppm Cd, while amylase activity was determined using Soluble Starch Agar. Six endophytic bacterial isolates were obtained, including four Gram-negative isolates (LO.1, LO.3, LO.4, and LU.2) and two Gram-positive isolates (LO.2 and LU.1). Four isolates grew at 100 ppm Cd, with isolate LO.3 showing the largest colony diameter (7.847 ± 0.130 mm). Isolate LO.1 exhibited the highest amylase activity, producing a clear zone diameter of 14.29 ± 0.91 mm. These findings indicate that lettuce endophytic bacteria have potential for bioremediation and biotechnological applications.
Copyrights © 2026