Pollution Research Paper

BACTERIAL EXTRACELLULAR POLYMERIC SUBSTANCES AND HEAVY METAL BIOREMEDIATION: CHALLENGES AND POSSIBILITIES

RAVNEET CHUG AND SHRUTI MATHUR

Abstract

Bioremediation is a process that uses plants and microorganisms or their enzymes to promote degradation and/or removal of contaminants from the environment. The physiological diversity of microorganisms, use of microbial metabolic ability for degradation/ removal of environmental pollutants provides an economic and safe alternative compared to other physicochemical methodologies. Heavy metal contamination is one of the most significant environmental issues, since metals are highly toxic to life forms, as they decrease both metabolic activity and diversity and accumulate via the food chain in ecosystems due to their persistence and recalcitrance. There is a dire need, therefore, for their control by mandating treatment at the source of pollution. Extracellular Polymeric substances (EPSs) are highly heterogeneous polymers containing a number of distinct monosaccharides and noncarbohydrate substituents that are species specific. Strong biosorbent behaviour of EPSs towards metallic ions has been observed and it is attributed to interaction between metal cations and negative charges of acidic functional groups of EPS. This review provides recent advancements in the knowledge of properties of EPS and their potential for use in removal of heavy metals from the environment and the challenges that need to be addressed for commercialization and technology development.