Characterization of mercury-reducing potential bacteria isolated from Keputih non-active sanitary landfill leachate, Surabaya, Indonesia under different saline conditions

摘要

The objectives of this research were to identify the capability of bacteria isolated from a non-active sanitary landfill to remove mercury under different saline conditions and to understand the removal kinetics. The mercury concentrations used in the minimum inhibitory concentration (MIC) test were 0, 5, 10, 15 and 20 mg/L. The capability of one selected bacterium from the MIC test to remove mercury under different saline conditions (0, 10, 20, and 30 parts per thousand) was also tested. Five indigenous bacteria were isolated from the Keputih non-active sanitary landfill, Surabaya, Indonesia. The MICs of mercury for FA-1, FA-2, FA-3, FA-4, and FA-5 were 5, 10, 5, 5, and 5 mg/L, respectively. Based on biochemical characterization, FA-2 was identified as Pseudomonas aeruginosa. The isolate of P. aeruginosa was capable of removing Hg under different saline conditions. The optimum saline condition for P. aeruginosa to remove Hg was 10 parts per thousand, with a removal percentage of 99.7 +/- 0,18 parts per thousand following pseudo-second-order kinetics (R-2 = 0.9939) with k(2) = 2.0059 mg substrate/g adsorbent/hr. Hence, isolated P. aeruginosa showed potential for the bioremediation of mercury-contaminated areas.