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Biology and Biotechnology of Environmental Stress Tolerance in Plants, Volume 3

class of autochthonous or zymogenous that secretes enzymes that lead to the

breakdown of the heavy metal compounds. Moreover, these microbes are

also helpful to detoxify environmental pollutants. It is efficient in reducing

toxic pollutants concentration below that causing human health risk, high in

cost-effective ratio and minimal/no-secondary pollution generation issues.

However, the efficiency of this method is severely limited by the unavail­

ability of the right strain of microbe and various environmental factors

like oxygen concentration, temperature, nutrient, and co-substrates avail­

ability and presence of potentially toxic compounds. Our present chapter

includes the problem associated with the toxicity pollutant which includes

both organic and inorganic pollutants. Moreover, we also tried to include a

sustainable, viable, and eco-friendly bioremediation technology which are

microbes-assisted bioremediation. Further, it would highlight the current

emerging issues and challenges, which require consideration for the future

development of novel technologies for the bioremediation of contaminated

sites.

1.1 INTRODUCTION

The recent trends of industrialization and rapid urbanization worldwide has

led to the incidence of xenobiotic contamination in soil and air. This contami­

nation of heavy metals and organic pollutants might result in nutrient runoff,

soil erosion, and ultimately lead to the pollution of soil and water bodies.

Increased incidence of soil pollution in terms of contamination of soil by the

enhanced release of the harmful substance (heavy metal and organic pollut­

ants) into the soil affect the flora and fauna of the soil. However, unlike the air

pollution that directly affect the lives of animal and human, soil pollution can

indirectly and detrimentally affect the lives of all form (Mishra, Mohammad,

& Roychoudhury, 2016). The primary sources of heavy metal include mining

and smelting of metallic ores, fertilizers, municipal; wastes, sewage sludge,

pesticides, burning of fossil fuels and electronic wastes (Devi et al., 2021;

Mondal et al., 2019). Both intended and unintended activities can result in

soil pollution, which broadly is of two types viz. point source and diffuse

pollution. The main sources of point-source pollution are anthropogenic

activities and are very common in urban areas. Diffuse pollution occurring

in the soils is difficult to analyze, and examples include the use of pesti­

cides in agriculture, soil erosion, uncontrolled disposal of waste, persistent

organic fertilizers and fertilizers that also add heavy metals (Wu & Chen,

2013). Remediation involves removing toxic or biohazardous contaminants