Bacterial exopolymeric liganded mesocage biogranules in vermicomposting to chromium bioaugmentation

Abstract

Anthropogenic industrial activity and natural reasons such as seepage from rocks, forest fires, and volcanic activity has lead to many hazardous metals in the environment. Almost all industrial activities release highly polluted effluents. The effluents could be loaded with toxic chemicals, heavy metals and organic wastes including pathogenic microbes. Among the components of effluents, heavy metals are the most persistent due to the practical difficulties in its complete removal or recovery. Chromium contamination of the environment implicates many problems to the ecosystem and the environment due to the toxic and carcinogenic properties of Cr (VI) even though Cr (III) is an essential micronutrient, less toxic and less mobile. The biotransformation ability of microorganisms can be used efficiently for novel and potential remediation of Cr (VI) pollution. Bioremediation of chromium happens by the conversion of Cr (VI) to Cr (III) and further stabilization. A comprehensive understanding of bioaugmentation mechanisms for the bioremediation of Cr (VI) is essentially required which involves the reduction of Cr (VI) to Cr (III). But crucial step is that the Cr (III) need to be stabilized since it is reported that Cr (III) oxidises to Cr (VI) in the presence of certain naturally occurring minerals which would pose serious implications the soil and the water bodies and also to the ecosystem it encompass.Microbes are attributed to possess heavy metal resistant and reduction capabilities. Bacteria develops resistance to heavy metals by the synthesis of Exopolysaccharides (EPS) and the resistance could also be due to the Cell Wall Associated Proteins (CWAP) (metal binding protein like Surface layer protein) in particular. newline