The bacterial mixtures containing all strains tolerated the highest minimum inhibitory concentration (MIC) of heavy metals, 9 mM(Fig. 2). Among the bacterial strains and mixtures tested, three of them (A3, KJ-46, and KJ-47) tolerated a heavy metal MIC of 6 mM.Previous research implied that because the members of bacterialmixtures communicate and differentiate, the bacterial mixtures can perform more complex tasks and survive in more changeable environments than a single culture (Brenner et al., 2008). Bacterial resistance to heavy metals is an important factor to be considered in the study of remediation because it is directly related to the survival and growth of the bacteria being used to recover contaminated sites (Li and Ramakrishna, 2011). It is known that metal resistance systems in bacteria are abundant and widespread, and their appearance frequencies range from a small percentage of the isolates in clean environments to nearly all isolates in heavily polluted environments (Barkay and Schaefer, 2001; Zouboulis et al.,2004).