Three Pb–tolerant bacterial strains were isolated from the rhizosphere of the Pb-accumulating plant B. asiatica collected from the Bo Ngam lead mine in Kanchanaburi Province, Thailand.  The strains were identified as Bacillus fusiformis, Microbacterium paraoxydans and Ochrobactrum intermedium by partial 16S rRNA sequence analysis. The bacterial strains grew well at 30°C within the pH range of 6-9. The growth response of each bacterial strain cultivated in a nutrient medium supplemented with 100 and 200 mg l^-1 of Pb was similar to that of control without Pb supplementation. However, at 300 mg l^-1 Pb, only O. intermedium cells survived after 2 days of incubation. The minimal inhibitory concentrations (MICs) of Pb, Cd and Zn which completely inhibited growth of each bacterial strain on a nutrient agar plate were determined.  With B. fusiformis and M. paraoxydans, the molar MICs of Pb were considerably higher than those of Cd or Zn.  With O. intermedium, the molar MIC of Pb was higher than that of Cd, but lower than that of Zn.  One mechanism for microbial cells to adapt to changing environmental condition and/or membrane-active agents is to alter the lipid composition of their cell membranes, thereby altering membrane fluidity. The result of fluorescence polarization measurement showed that the membranes of O. intermedium cells grown in the presence of high concentration (250 mg l^-1) of Pb were less fluid than those grown in the absence of Pb.  The results are of interest in efforts to understand how rhizobacteria interact with heavy metals.