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

The ciliate, Vorticella microstoma, showed tolerance against Cd2+ (22 μg/mL), Cu2+ (22 μg/mL), Ni2+ (17 μg/mL), and Hg2+ (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 Cd2+, 49% for Cu2+, 35% for Ni2+, and 49% for Hg2+ after 8 days of metal stress. The order of resistance to heavy metal, in terms of reduction in the cellular population, was Ni2+ < Hg2+ = Cu2+ < Cd2+. Metal‐uptake capability of the ciliate was worked out for its potential use as bioremediator of wastewater. V. microstoma decreased 72% of Cd2+, 82% of Cu2+, 80% of Ni2+, and 74% of Hg2+ from the medium after 96 h of incubation. V. microstoma was also able to remove 73% of Cd2+, 80% of Cu2+, 83% of Ni2+, and 76% of Hg2+ 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