Tolerance and biosorption of mercury by microbial consortia: Potential use in bioremediation of wastewater

Mercury resistant microorganisms (bacteria,yeast and protozoa) were isolated from industrial effluents of tanneries and identified as bacillus licheniformis,candida parapsilosis and tetrahymena rostrata on the basis of 16s rrna and 18srrna gene sequence analysis. all microorganisms showed typical growth pattern except for the lag phase. the lag phase extended in the presence of mercury. mercury processing ability of microorganisms was evaluated individually and in different combinations. b. licheniformis,c. parapsilosis and t. rostrata removed 73%,80% and 40% of mercury,respectively,when used individually. b. licheniformis and c. parapsilosis reduced 85%,c. parapsilosis and t. rostrata removed,77% and b. licheniformis and t. rostrata removed 73% mercury from the medium. combination of three microorganisms viz.,b. licheniformis,c. parapsilosis and t. rostrata when used simultaneously,removed 88% of hg2+ after 96 h of incubation. it was concluded from this part of study that bacteria and yeast could make much more efficient inoculum for remediation of mercury-contaminated industrial waste water. copyright 2013 zoological society of pakistan.