Application of Extremophilic Microorganisms in Decolorization and Biodegradation of Textile Wastewater - Microbial Degradation of Synthetic Dyes in Wastewaters - page 276

The exploration of extremobiosphere targets at discovery of extremophile micro-
organisms with new metabolisms, natural products, biocatalysts and other services
(Schiraldi and De Rosa 2002 ).
Extremophilic microorganisms have many applications in biotechnology,
medicine and industry. Extremozymes are one of the most important products of
extremophiles not only because of their industrial application, but also because they
can also be used as a model system for the study of stabilization and enzyme
activation mechanisms of protein structure-functional properties (Demirjian et al.
2001 ). Enzymes of thermophilic, hyperthermophilic, alkaliphilic and psycrophilic
groups of extremophilic microorganisms are the most promising for industrial
applications (Van Den Burg 2003 ). Highly thermostable hydrolases, like cellulases,
amylases, pectinases, chitinases, xylanases, lipases, proteases, pullulanases, glucose
isomerases, alcohol dehydrogenases, and esterases with broad industrial application
can be extracted from thermophilic and hyperthermophilic microorganisms. Some
other kinds of thermostable enzymes, like DNA polymerase, DNA ligase, restric-
tion enzymes and phosphatase with application in molecular biology and medicine,
are also produced by extremophilic microorganisms (Gomes and Steiner 2004 ;
Egorova and Antranikian 2005 ). Psychrophilic microorganisms with hydrolases,
like B-glucanases, pectinases, cellulases, and proteases, have some potential
applications in the waste treatment and food industry, while cold adapted enzymes
are of emerging interest in the detergent production industries (Cavicchioli et al.
2011 ). Alkaliphilic microorganisms are source of enzymes which are stable at high
pH values. Some examples of these enzymes with application in industrial sector
are elastase and keratinase in cosmetic industries and some other hydrolases, like
cellulases, proteinases, amylases, lipases with application in detergent production
industries. Some of extremophilic microbial enzymes have the potential to be used
in the biosensor systems (D

Auria et al. 2002 ).
Along with these enzymes, other biologically active substances and biopolymers
of extremophiles have also put their mark on industry and medicine, osmoprotec-
tant compounds, like ectoin and betain, bacteriorhodopsin (Oesterhelt and
Stoeckenius, 1973 ; Trivedi et al. 2011 ),

'

n et al. 2003 ; Lamers et al.
2008 ), halocins and microhalocins (Haseltine et al. 2001 ;O

ʲ -carotene (Le ó

connor and Shand
2002 ) and long-chained poly unsaturated fatty acids are some examples of bio-
logically active substances of extremophiles with biotechnological applications.
Extremophiles are also source of useful biopolymers (Barbara et al. 2012 ) like
bioplastics (Lu et al. 2009 ) and exopolysaccharides (Nicolaus et al. 2010 ). Gas
vesicle and liposomes of some halophilic bacteria can be used for vaccine devel-
opment (Stuart et al. 2001 , 2004 ).
One of the most interesting applications of extremophilic microorganisms is
their potential in bioremediation. Bioremediation is one of the most effective and
successful cleaning techniques for removal of toxicants from polluted environments
(Kumar et al. 2011 ). There are some strains of psychrophilic (Aislabie et al. 2006 )
and halophilic microorganisms (Nicholson and Fathepure 2004 , 2005 ; Liebgott
et al. 2007 ; Feng et al. 2012 ) which have been reported to degrade hydrocarbon
compounds. These strains have the potential to be used for oil spill or oil

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eld