Resistance and uptake of heavy metals by Vorticella microstoma and its potential use in industrial wastewater treatment

The ciliate, Vorticella microstoma, showed tolerance against Cd 2+ (22 μg/mL), Cu 2+ (22 μg/mL), Ni 2+ (17 μg/mL), and Hg 2+ (16 μg/mL). The metal ions slowed down the growth of the ciliate as compared to the culture grown without metal stress. The decrease in cell population was 60% for Cd 2+ , 49% for Cu 2+ , 35% for Ni 2+ , and 49% for Hg 2+ after 8 days of metal stress. The order of resistance to heavy metal, in terms of reduction in the cellular population, was Ni 2+ < Hg 2+ = Cu 2+ < Cd 2+ . Metal‐uptake capability of the ciliate was worked out for its potential use as bioremediator of wastewater. V. microstoma decreased 72% of Cd 2+ , 82% of Cu 2+ , 80% of Ni 2+ , and 74% of Hg 2+ from the medium after 96 h of incubation. V. microstoma was also able to remove 73% of Cd 2+ , 80% of Cu 2+ , 83% of Ni 2+ , and 76% of Hg 2+ from the industrial wastewater after 6 days of incubation at room temperature. The multiple heavy metal uptake ability of V. microstoma can be exploited for metal detoxification and environmental clean‐up operations. © 2010 American Institute of Chemical Engineers Environ Prog, 2010