Description

Multiple metal resistant ciliates viz., Stylonychia mytilus, Euplotes mutabilis, Paramecium caudatum, Oxytricha fallax and Vorticella microstoma, isolated from industrial wastewater from Kasur tanneries were found to be resistant to various heavy metals viz., chromium, cadmium, copper, lead, mercury, zinc and nickel. These protozoans showed remarkable ability to survive under stress full conditions in the industrial waste water. These microorganisms cope with this heavy concentration of heavy metal ions by uptaking 85-95 % of metal ions from the culture medium. Some of these protozoans survive despite toxic metal by effluxing them out. In this study PAGE analysis of total proteins of the protozoan isolates showed that a number of new proteins were induced against Pb2+, Cr6+, and Cd2+ Certain proteins, however, disappeared as a result of the metal stress. These protozoans because of their special metal uptaking ability can be considered as best candidates for the removal of the various heavy metals from industrial wastewater.