Copper Tolerant Yeast, Candida tropicalis, Isolated from Industrial Effluents: its Potential use in Wastewater Treatment

The present study is aimed at assessing the ability of Cu 2+ resistant yeast, Candida tropicalis, to uptake metal from the medium. The minimum inhibitory concentration of Cu 2+ against Candida tropicalis ranged between 2300-2300 µg/mL. The yeast could also tolerate Pb 2+ (1200 µg/mL), Cr 6+ (2000 µg/mL), Cd 2+ (2800 µg/mL), Zn 2+ (3100 µg/mL), Ni 2+ (3000 µg/mL) and Hg 2+ (2400 µg/mL). The yeast isolate showed typical growth curves but lag and log phases extended in the presence of copper. Yeast isolate showed optimum growth at 30oC and pH 4. Metal processing ability of the isolate was determined in a medium containing 100 µg/mL of Cu 2+ . Candida tropicalis could reduce 74% of copper from the medium after 96 hours and was also capable to remove Cu 2+ 16%, 20%, 29%, 43%, 46%, 55, and 68% from the medium after 6, 12, 18, 24, 30, 48 and 72 hours, respectively. C. tropicalis could also efficiently uptake 82% copper from the medium after 96 hours and was also able to remove Cu 2+ 64% and 74% from the wastewater after 4 and 8 days, respectively. The metal uptake ability suggests possibility of using this yeast strain for removal of copper from Cu 2+ contaminated wastewater.