77
on a large scale using bioreactors facilitating extensive field trials and application
studies.
Enzymes are mostly proteinaceous and hold immense structural integrity and
offer much selectivity in their action. It is the diversity existing within the protein
structure of the enzyme that gives way to novel activities in complex and stressed
environments. The wide range of substrate selectivity distributed among the infinite
domain of plant, animal and microbial enzymes makes them highly competent in
acting as principal agents in most of the bioprocesses including bioremediation and
biocontrol.
3.2
Enzymes in Bioremediation
The decomposition/mineralisation of materials through biological agents is referred
to as biodegradation. Microorganisms are effective mediators of biodegradation
because they have diversified metabolic capabilities. Biodegradation is unique and
effective as it results in complete mineralisation of toxic chemicals or results in the
generation of biogas (Providenti et al. 1993; Jain et al. 2005). Microorganisms support life on earth through their sole activity of biogeochemical cycling. During the
course of evolution on earth, which covered both aerobic and anaerobic phases,
microorganisms have been offering versatile biochemical pathways. This equipped
them to utilise or degrade a given substance and hence hypothetically they are said
to be infallible. Microorganisms can be considered as metabolic machines, dependent on gathering chemicals from their environment to obtain carbon, other elements and energy to compete favourably against other microbes.
Biodegradation is a triple corner process which is influenced by pollutants, different environments and type of organisms. Biodegradation involves the application
of actinomycetes, yeast, fungi or bacteria (Strong and Burgess 2008; Ruiz-Duenas
et al. 2009) and it helps in restoring the original nature of the environment. These
approaches are mainly based on two principles, metabolism or absorption of xenobiotic by living organisms. Microorganisms have the potential to utilise a variety of
compounds as their energy and carbon source and this often results in structural
changes of the substrate (De Schrijver and De Mot 1999; Nair et al. 2009). Biological
methods have gained importance because of their simple operation and as they generate very small amounts of secondary wastes besides bringing complete mineralisation (Alfonsin et al. 2015; Rajamohan et al. 2015).
In recent times, many microbial ecologists have identified varieties of microbial
species that act as efficient degraders of toxic organic compounds (Nair et al. 2007,
2009; Joseph et al. 2010; Cherian and Jayachandran 2010). A single microorganism
is typically incapable of degrading a mixture of toxic compounds. Hence a consortium or mixed culture designed in a proper way can degrade a wide range of toxic
compounds present in a mixture very effectively (Al-Wasify and Hamed 2014;
Vijayana et al. 2014; Dhanya 2016). Development of syntropic bacterial consortia
with specialised catabolic steps is a less controversial approach in the biodegradation of complex pollutants.
3 Enzymes for Bioremediation and Biocontrol
on a large scale using bioreactors facilitating extensive field trials and application
studies.
Enzymes are mostly proteinaceous and hold immense structural integrity and
offer much selectivity in their action. It is the diversity existing within the protein
structure of the enzyme that gives way to novel activities in complex and stressed
environments. The wide range of substrate selectivity distributed among the infinite
domain of plant, animal and microbial enzymes makes them highly competent in
acting as principal agents in most of the bioprocesses including bioremediation and
biocontrol.
3.2
Enzymes in Bioremediation
The decomposition/mineralisation of materials through biological agents is referred
to as biodegradation. Microorganisms are effective mediators of biodegradation
because they have diversified metabolic capabilities. Biodegradation is unique and
effective as it results in complete mineralisation of toxic chemicals or results in the
generation of biogas (Providenti et al. 1993; Jain et al. 2005). Microorganisms support life on earth through their sole activity of biogeochemical cycling. During the
course of evolution on earth, which covered both aerobic and anaerobic phases,
microorganisms have been offering versatile biochemical pathways. This equipped
them to utilise or degrade a given substance and hence hypothetically they are said
to be infallible. Microorganisms can be considered as metabolic machines, dependent on gathering chemicals from their environment to obtain carbon, other elements and energy to compete favourably against other microbes.
Biodegradation is a triple corner process which is influenced by pollutants, different environments and type of organisms. Biodegradation involves the application
of actinomycetes, yeast, fungi or bacteria (Strong and Burgess 2008; Ruiz-Duenas
et al. 2009) and it helps in restoring the original nature of the environment. These
approaches are mainly based on two principles, metabolism or absorption of xenobiotic by living organisms. Microorganisms have the potential to utilise a variety of
compounds as their energy and carbon source and this often results in structural
changes of the substrate (De Schrijver and De Mot 1999; Nair et al. 2009). Biological
methods have gained importance because of their simple operation and as they generate very small amounts of secondary wastes besides bringing complete mineralisation (Alfonsin et al. 2015; Rajamohan et al. 2015).
In recent times, many microbial ecologists have identified varieties of microbial
species that act as efficient degraders of toxic organic compounds (Nair et al. 2007,
2009; Joseph et al. 2010; Cherian and Jayachandran 2010). A single microorganism
is typically incapable of degrading a mixture of toxic compounds. Hence a consortium or mixed culture designed in a proper way can degrade a wide range of toxic
compounds present in a mixture very effectively (Al-Wasify and Hamed 2014;
Vijayana et al. 2014; Dhanya 2016). Development of syntropic bacterial consortia
with specialised catabolic steps is a less controversial approach in the biodegradation of complex pollutants.
3 Enzymes for Bioremediation and Biocontrol