Abstract Extremophiles are microorganisms that flourish in habitats of extreme
environments, including in high concentration of salts, pollutants, high or low
temperature, an acidic or alkaline pH. All extreme environments are dominated by
microorganisms belonging to Archaea, the third domain of life, evolutionary distinct
from Bacteria and Eucarya. Over the past few years, the molecular biology of
extremophilic Archaea has stimulated a lot of interest in the field of bioremediation.
Bioremediation is the use of microorganisms for the degradation or removal of
contaminants. Contamination of soils, sediments and water due to anthropogenic
activities is a matter of concern at global level. Bioremediation has emerged as an
effective solution for these problems. Most bioremediation research has focused on
the processes performed by the domain Bacteria. Recently, extremophiles are the
focus of growing interest for bioremediation because they can tolerate very harsh
environmental conditions due to their ability to produce an array of molecules or
extremozymes capable of functioning in the environment without denaturing. These
extremozymes from extremophilic microorganisms have special characteristics such
as stability to elevated temperature, extremes of pH, organic solvents and high ion
strength. Due to the stability and persistence of these extremophilic microorganisms
under adverse environmental conditions, they can be explored finding new species
for using in the bioremediation of environments contaminated with extremely
recalcitrant pollutants. Here, we provide an overview of the archaeal extremophilic
microorganisms such as thermopiles, acidophiles, halophiles which have potential
applications in the field of bioremediation of environmental pollutants, including
hydrocarbons, heavy metals, pesticides, petroleum and wastewater treatments.
Keywords Extremophiles · Bioremediation · Extremozymes · Pollutants · Archaea
12.1 Introduction
Microorganisms are the most ubiquitous living entities on our planet and are also the
diverse organisms present almost everywhere on the Earth. It is estimated that about
1% of the total microorganisms have been isolated and identified so far and still there
are unexplored niches where these microorganisms may be present. A variety of
microbes inhabit extreme environments. The extreme environments include high salt
concentration, pH, pressure and temperature and low temperature, pH, nutrients
concentration and water availability. In addition, high levels of radiations, harmful
heavy metals and toxic compounds including organic solvents are the extreme
environments. Extremophilic microorganisms are a largely unexplored group that
have the abilities to thrive in extreme conditions.
In year 1965, Thomas Brock, a microbiologist, discovered in the thermal vents of
Yellowstone National Park a new form of bacteria, Thermus aquaticus that can
survive at near-boiling temperatures (Fig. 12.1).
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S. Kaushik et al.
environments, including in high concentration of salts, pollutants, high or low
temperature, an acidic or alkaline pH. All extreme environments are dominated by
microorganisms belonging to Archaea, the third domain of life, evolutionary distinct
from Bacteria and Eucarya. Over the past few years, the molecular biology of
extremophilic Archaea has stimulated a lot of interest in the field of bioremediation.
Bioremediation is the use of microorganisms for the degradation or removal of
contaminants. Contamination of soils, sediments and water due to anthropogenic
activities is a matter of concern at global level. Bioremediation has emerged as an
effective solution for these problems. Most bioremediation research has focused on
the processes performed by the domain Bacteria. Recently, extremophiles are the
focus of growing interest for bioremediation because they can tolerate very harsh
environmental conditions due to their ability to produce an array of molecules or
extremozymes capable of functioning in the environment without denaturing. These
extremozymes from extremophilic microorganisms have special characteristics such
as stability to elevated temperature, extremes of pH, organic solvents and high ion
strength. Due to the stability and persistence of these extremophilic microorganisms
under adverse environmental conditions, they can be explored finding new species
for using in the bioremediation of environments contaminated with extremely
recalcitrant pollutants. Here, we provide an overview of the archaeal extremophilic
microorganisms such as thermopiles, acidophiles, halophiles which have potential
applications in the field of bioremediation of environmental pollutants, including
hydrocarbons, heavy metals, pesticides, petroleum and wastewater treatments.
Keywords Extremophiles · Bioremediation · Extremozymes · Pollutants · Archaea
12.1 Introduction
Microorganisms are the most ubiquitous living entities on our planet and are also the
diverse organisms present almost everywhere on the Earth. It is estimated that about
1% of the total microorganisms have been isolated and identified so far and still there
are unexplored niches where these microorganisms may be present. A variety of
microbes inhabit extreme environments. The extreme environments include high salt
concentration, pH, pressure and temperature and low temperature, pH, nutrients
concentration and water availability. In addition, high levels of radiations, harmful
heavy metals and toxic compounds including organic solvents are the extreme
environments. Extremophilic microorganisms are a largely unexplored group that
have the abilities to thrive in extreme conditions.
In year 1965, Thomas Brock, a microbiologist, discovered in the thermal vents of
Yellowstone National Park a new form of bacteria, Thermus aquaticus that can
survive at near-boiling temperatures (Fig. 12.1).
294
S. Kaushik et al.