Remediation of Soil Organic Pollutants by Microbes from Extreme Environment

Soil organic pollutants (OPs) commonly include biphenyl compounds, dibenzofurans and polycyclic aromatic hydrocarbons accumulated due to natural or anthropogenic means. The overuse of pesticides and organic chemicals in agriculture, organic solvents from various industries, pharmaceutical and cosmetic products, dyes of the textile industry, waste dumping, organic fuels and accidental spills of chemical hazards are the frequent sources of soil OPs. The soil environment is one of the complex systems and thus difficult to reclaim. The pervasive and accumulative nature of soil OPs adversely affects niches of soil organisms, plants, animals and human beings. Bioremediation approaches have been identified as the most promising and safe tools for the reclamation of such contaminated soils. The extremophiles are a group of microorganisms that can survive in extreme environmental conditions such as high salinity, alkalinity, extreme temperatures and other toxic environments; thus, attention has been drawn to the remedial application of a vast range of extreme environments. The extremophiles have been identified as reliable candidates in the bioremediation of environmental pollutants because of their stability and unique features, including specific enzymes that can digest pollutants. This chapter specifies the sources of OP in the soil, the impact and nature of toxicity, soil OP degradation by various microbial groups, mechanisms, present discoveries and direction to future research in reducing OPs in soil environments.