This study aimed to apply superior mercury resistant bacteria isolate that has been evaluated on a prior study. This experimental study was done in laboratorium for the research preparation, and in green house for application isolate bacteria using simple open and closed bioreactor. Observation was done on day thirty and sixty after incubation. The result shows application of superior mercury resistant bacteria isolate on a small scale with ex situ using simple open bioreactor could lower mercury level from 200 ppm to 0.08-4.08 ppm or about 97.96-99.96% until day 60 (2 months) after incubation. The best isolate in lowering mercuty is MRB5. Meanwhile, application of superior mercury resistant bacteria isolate on a small scale with ex situ using simple closed bioreactor could lower mercury level from 200 ppm to 0.18-11.03 ppm or about 94.49-99.91% until day 60 (2 months) after incubation. Isolate MRB5 is the best isolate used in the research.