Potential application of bacterial biofilm for bioremediation of toxic heavy metals and dye-contaminated environments

Biofilm-mediated bioremediation is now gaining interest as an emerging technology for the sustainable removal of toxic recalcitrant pollutants such as heavy metals and dyes. Biofilms are a naturally-growing surface attached with cellular aggregates embedded with a self-synthesized matrix. The secretion of sticky, viscous, and negatively-charged extracellular polymeric substances by bacterial biofilm matrix makes it more resistant against various toxic compounds. Bacterial biofilms also have a greater tolerance toward changing environmental conditions than when in their free planktonic phase. Horizontal gene transfer and chemotaxis activities of biofilm organisms can make them unique for their bioremediation application. Numerous studies have been undertaken on diseases created by the formation of biofilms, however, less attention has been paid toward environmental applications. In this chapter, the formation, development, and application of bacterial biofilm for bioremediation of toxic metals and dyes are described. The association of several biofilm components in bioremediation process, factors affecting them, and possible interaction mechanisms are reported.