Thermophilic microorganisms for bioremediation of industrial pollutants including hydrocarbons and heavy metals

Industrialization and urbanization have led to the constant discharge of hazardous pollutants such as effluents, hydrocarbons, and heavy metals, which pose a grave threat to ecological balance and human beings' well-being. Traditional physiochemical techniques for the treatment of environmental pollutants are energy-intensive, expensive, and inefficient in extreme environments. Hence, there is a need to explore alternative strategies to address the above problems. Thermophiles are microorganisms that grow in high temperatures, and they have recently been regarded as viable sources for bioremediation due to their metabolic resilience, enzyme stability, and resistance to industrial conditions. The current paper presents an in-depth literature review concerning the use of thermophiles in the bioremediation of industrial effluents, hydrocarbons, and heavy metals. It further evaluates the engineering potential of thermophiles for bioremediation and highlights the molecular and physiological adaptation mechanisms that allow them to survive in extreme environments. The most important applications of thermophiles in the degradation of hydrocarbons, detoxification of heavy metals, bioremediation of textiles, petrochemical and mining sector effluents, and utilization of high temperature bioreactors are discussed here. Besides that, some of the latest advancements made in the fields of metagenomics, metabolic engineering, and synthetic biology and how these have enabled new possibilities in the use of thermophiles for environmental biotechnology are reviewed. The challenges associated with cultivating, upscaling, and optimization of processes involving thermophiles have also been mentioned along with innovative solutions to deal with these hurdles. Finally, the importance of thermophile-mediated bioremediation in achieving the United Nations Sustainable Development Goals (SDGs) like clean water and sanitation, responsible consumption and production, climate action, and sustainable industry is highlighted.