Biodegradation of persistent organic pollutants in soil, water and pristine sites by cold-adapted microorganisms: Mini review

Although persistent organic pollutants (POPs) have been banned since 1970s in many countries, their extensive use and false disposition have led to serious environmental pollution problems. POPs and their metabolic products are ubiquitous in all ecological niches. In addition, pollution has extended to pristine cold sites as well, which are now considered as the ultimate sink for many POPs. However, slight information is available on the biodegradation of POPs in such sites. Furthermore, it is estimated that more than 70 % of earth's surface is cold. Since temperature plays a significant role in controlling microbial metabolism, mesophilic microorganisms are inefficient at eliminating POPs at low temperatures. On the contrary, cold-adapted microorganisms are physiologically distinct and offer tremendous natural source of enzymes that work effectively in cold. Such organisms have high catalytic efficiency at low temperatures and have great economical and environmental potential. This review describes the microbial enzymes features that contribute to the adaptation to cold and discuss the potential of cold-adapted microorganisms to bioremediate pristine cold sites contaminated with POPs where mesophilic microorganisms are ineffective. (C) 2015 Elsevier Ltd. All rights reserved.