Application of Enzymes in Textile Functional Finishing
123
immobilised enzymes have shown increase activity in different stages of textile finishing. These will open a new path towards future application in textile industry
for production of comfortable clothes. Enzymes are being used in order to increase
the rate and effectivity of reaction. Nanoparticle is a way to increase the rate of
reaction. Formation of enzyme-nanoconjugates with other chemical increases the
efficacy of reaction. Nano-conjugates of citric acid and Fe 3 O 4 with protease has
been developed which is used in pretreatment of wool. This process will increase
tensile strength of woollen fiber and also make it resistance to alkaline condition
[32]. Enzyme immobilised nanoparticle shows increased catalytic activity which is
very much preferable for increasing production rate [33]. ZnO- and TiO 2 nanoparticle along with citric acid/sodium is used for treatment of denim in eco-friendly way
after enzymatic treatment of denim fabric [34]. It is well understood that in addition
with textile finishing process above mentioned advanced techniques are also being
used in bioremediation of waste water.
6 Laccase in Decolorisation of Textile Effluent
and Mitigating Important Environmental Issue
In textile, mainly synthetic azo dyes are used in order to make colour variation in
wearers. Dying is a main part of finishing process. Dyes are water soluble and bind
with fibers to make them colourful. Nearly, 10–15% dyes get released through effluent
without binding with fibers [35]. These dyes are very harmful to the environment
and human beings because of being a xenobiotic compound. Traditional physical
and chemical methods can remove dyes partially and produce aromatic amine as
secondary pollutant, but enzymatic treatment has the ability to remove dyes efficiently
without producing any secondary pollutants [35].
Multicopper oxidase enzyme Laccase is a very good source of enzyme in order to
remove unused dyes from waste water before release. Laccase has ability to degrade
azo dyes like methyl orange effectively [36]. This special enzyme isolated from
microorganisms is reported extensively for its capacity in azo dye degradation. It has
non-specific oxidation capacity which is imperative for bioremediation process. On
the other hand laccase doesn’t necessitate any cofactor or oxygen for reaction [37].
Mainly dye molecule with low molecular weight is being used as redox mediator
in the course of decolourisation. Aromatic azo dyes, phenolic compound, etc. in
addition with pesticides is degraded by laccase by redox reaction [38]. Now, pH
stable and thermo-stable laccase are being isolated which also exhibit tolerance to
organic solvent [39]. In the path of reaction, laccase uses Cu
2+ as a mediator to oxidise
aromatic amine. Recently, in order to increase the degradation capacity laccase is
being immobilised. This immobilised and insolubilised laccase has more efficiency
to remove micro-pollutants in addition with dyes [40]. Immobilized laccase from
fungal source has been used with the support of SiO 2 on magnetic separators to
remove azo dyes from waste water efficiently [41]. Nanocomposites of enzymes are
123
immobilised enzymes have shown increase activity in different stages of textile finishing. These will open a new path towards future application in textile industry
for production of comfortable clothes. Enzymes are being used in order to increase
the rate and effectivity of reaction. Nanoparticle is a way to increase the rate of
reaction. Formation of enzyme-nanoconjugates with other chemical increases the
efficacy of reaction. Nano-conjugates of citric acid and Fe 3 O 4 with protease has
been developed which is used in pretreatment of wool. This process will increase
tensile strength of woollen fiber and also make it resistance to alkaline condition
[32]. Enzyme immobilised nanoparticle shows increased catalytic activity which is
very much preferable for increasing production rate [33]. ZnO- and TiO 2 nanoparticle along with citric acid/sodium is used for treatment of denim in eco-friendly way
after enzymatic treatment of denim fabric [34]. It is well understood that in addition
with textile finishing process above mentioned advanced techniques are also being
used in bioremediation of waste water.
6 Laccase in Decolorisation of Textile Effluent
and Mitigating Important Environmental Issue
In textile, mainly synthetic azo dyes are used in order to make colour variation in
wearers. Dying is a main part of finishing process. Dyes are water soluble and bind
with fibers to make them colourful. Nearly, 10–15% dyes get released through effluent
without binding with fibers [35]. These dyes are very harmful to the environment
and human beings because of being a xenobiotic compound. Traditional physical
and chemical methods can remove dyes partially and produce aromatic amine as
secondary pollutant, but enzymatic treatment has the ability to remove dyes efficiently
without producing any secondary pollutants [35].
Multicopper oxidase enzyme Laccase is a very good source of enzyme in order to
remove unused dyes from waste water before release. Laccase has ability to degrade
azo dyes like methyl orange effectively [36]. This special enzyme isolated from
microorganisms is reported extensively for its capacity in azo dye degradation. It has
non-specific oxidation capacity which is imperative for bioremediation process. On
the other hand laccase doesn’t necessitate any cofactor or oxygen for reaction [37].
Mainly dye molecule with low molecular weight is being used as redox mediator
in the course of decolourisation. Aromatic azo dyes, phenolic compound, etc. in
addition with pesticides is degraded by laccase by redox reaction [38]. Now, pH
stable and thermo-stable laccase are being isolated which also exhibit tolerance to
organic solvent [39]. In the path of reaction, laccase uses Cu
2+ as a mediator to oxidise
aromatic amine. Recently, in order to increase the degradation capacity laccase is
being immobilised. This immobilised and insolubilised laccase has more efficiency
to remove micro-pollutants in addition with dyes [40]. Immobilized laccase from
fungal source has been used with the support of SiO 2 on magnetic separators to
remove azo dyes from waste water efficiently [41]. Nanocomposites of enzymes are