Intracellular bioaccumulation of zinc by an Enterobacter species

Bacterial strains tolerant to the presence of 100 mg/l zinc ions were isolated from a water reclamation system. Each of the organisms were screened for their ability to accumulate zinc at the above mentioned concentration. The organism capable of maximum zinc accumulation was identified as an Enterobacter species and intracellular zinc deposition by this micro-organism was determined using energy dispersive X-ray analysis, transmission electron microscopy and a metal-staining technique at the light microscopy level. Further studies revealed that growth and glucose utilization by this isolate were inhibited in the presence of zinc, compared to a control culture grown in the absence of zinc.