Chapter 25 - Microbial biofilm-mediated bioremediation of heavy metals: a sustainable approach

Abstract

The heavy metal contamination of soil and their subsequent entry to the food chain has deteriorated the environment and quality of life. A multifold rise in industrialization and other anthropogenic activities have amplified the problem, thus requires immediate and efficient attention. Nowadays a large number of in situ and ex situ remediation technologies using physical, chemical, and biological principles have been employed to rectify the contaminated soils. These techniques show promising results toward quenching of heavy metals from the soil, but some setbacks associated with their applicability have been reported as well. In this regard, microbial biofilm-mediated bioremediation of heavy metals is becoming an emerging, efficient, and sustainable technology. Biofilms, aggregates of microbes on biotic and abiotic surfaces, being resistant to toxic contaminants and other harsh environmental conditions, are a potential and eco-friendly approach to deal with heavy metals. Their extensive, easy-to-grow mode, low cost, and ability to grow under high concentration of heavy metals are some of the positive attributes of the use of microbial-biofilms in heavy metal remediation. This chapter summarizes the role of different microbial-biofilms in rectifying the heavy metal-polluted environment, chemotactic responses of microbial biofilms to pollutants, factors affecting the bioremediation process, mechanisms involved in microbial bioremediation, and the perspective of genetically engineered biofilm.