8.8.1 Metagenomics
Metagenomics include phylogenetic analysis of soil microbial flora (Daniel 2005)
for creating soil-based metagenomics library. It promises a continuous source of
pollutant-degrading genes for increased efficiency and utility of transgenic
(microbes and plants) technologies for direct use in bioremediation program (Daniel
2005). This technology also facilitates the mass production of the degrading
enzymes from uncultivable bacteria for improvement of enzymatic remediation
technology. By this technique, we can produce a marketable product based on
bioremediation gene/enzyme product from uncultivable microbes (Rayu et al.
2012). For example, thermostable pyrethroid hydrolyzing enzyme could be used in
the detoxification of pyrethroids (Fan et al. 2012), a novel gene responsible for the
degradation of 3,5,6-trichloro-2-pyridinol; a persistent and toxic metabolite of the
insecticide chlorpyrifos was isolated (Math et al. 2010) from cow rumen and gene
products for remediation including biphenyl-degrading genes (Sul et al. 2009).
8.8.2 Metabolic Engineering
Metabolic engineering includes the improvement of cellular activities by manipulations of enzymatic, transport, and regulatory functions of the cell with the use of
recombinant DNA technology (Nielsen 2001). By this technique, we can combine
analysis of the metabolic pathway and other pathways that can help to improve
cellular properties by designing and implementing rational genetic modifications
(Koffas et al. 1999). This type of metabolic pathway analysis is rapidly becoming
one of the significant features of bioremediation, e.g., Pseudomonas putida degrades
chloro- as well as methylo-aromatics; the combination of tod and tol pathways in
P. putida can increase biodegradation rate of benzene, toluene, and p-xylene (Rayu
et al. 2012).
8.8.3 Protein/Enzyme Engineering
Improving the stability, substrate specificity, and kinetic properties of proteins/
enzymes can be engineered (Dombkowski et al. 2014). It can be done to fine-tune
enzymes for desired substrate specificities and stereo-selectivity. This method helps
to modify the active site volume and topology of cytochrome P450cam enhanced the
catalytic activity of the enzyme (Kumar 2010; Holloway et al. 1998). Another
modification is the incorporation of multiple binding sites within a single peptide,
for binding of the co-factors and other small molecules, can enhance the catalytic
power of the enzyme; this is found to bioremediate the metal wastes (Pazirandeh
et al. 1998).
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M. K. Chitara et al.
Metagenomics include phylogenetic analysis of soil microbial flora (Daniel 2005)
for creating soil-based metagenomics library. It promises a continuous source of
pollutant-degrading genes for increased efficiency and utility of transgenic
(microbes and plants) technologies for direct use in bioremediation program (Daniel
2005). This technology also facilitates the mass production of the degrading
enzymes from uncultivable bacteria for improvement of enzymatic remediation
technology. By this technique, we can produce a marketable product based on
bioremediation gene/enzyme product from uncultivable microbes (Rayu et al.
2012). For example, thermostable pyrethroid hydrolyzing enzyme could be used in
the detoxification of pyrethroids (Fan et al. 2012), a novel gene responsible for the
degradation of 3,5,6-trichloro-2-pyridinol; a persistent and toxic metabolite of the
insecticide chlorpyrifos was isolated (Math et al. 2010) from cow rumen and gene
products for remediation including biphenyl-degrading genes (Sul et al. 2009).
8.8.2 Metabolic Engineering
Metabolic engineering includes the improvement of cellular activities by manipulations of enzymatic, transport, and regulatory functions of the cell with the use of
recombinant DNA technology (Nielsen 2001). By this technique, we can combine
analysis of the metabolic pathway and other pathways that can help to improve
cellular properties by designing and implementing rational genetic modifications
(Koffas et al. 1999). This type of metabolic pathway analysis is rapidly becoming
one of the significant features of bioremediation, e.g., Pseudomonas putida degrades
chloro- as well as methylo-aromatics; the combination of tod and tol pathways in
P. putida can increase biodegradation rate of benzene, toluene, and p-xylene (Rayu
et al. 2012).
8.8.3 Protein/Enzyme Engineering
Improving the stability, substrate specificity, and kinetic properties of proteins/
enzymes can be engineered (Dombkowski et al. 2014). It can be done to fine-tune
enzymes for desired substrate specificities and stereo-selectivity. This method helps
to modify the active site volume and topology of cytochrome P450cam enhanced the
catalytic activity of the enzyme (Kumar 2010; Holloway et al. 1998). Another
modification is the incorporation of multiple binding sites within a single peptide,
for binding of the co-factors and other small molecules, can enhance the catalytic
power of the enzyme; this is found to bioremediate the metal wastes (Pazirandeh
et al. 1998).
218
M. K. Chitara et al.