Effect of Ag+ on growth of Klebsiella pneumoniae KW and metal uptake. (A) Ag (0.3-5mM) was added in log phase cells and 5µl was spotted with 2h time intervals. Addition of the metal appeared to be highly toxic and strength of colonies decreased with increasing concentration at time 0 and no visible growth at 2hs. Growth reinitiated at 4 h that increased afterwards. (B) Addition of higher concentrations caused further delay and it took 6 h for cells to adapt and growth reinitiation. (C) Spreading of 100µl at 2h post metal addition showed the presence of small number of alive cells. (D) Brown coloration of colonies show silver accumulation in the cells.