Biotechnology: An Eco-friendly Tool of Nature for Textile …
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stone washing produces large amounts of sludge approximately 18 metric tons per
weak which clog up the wastewater streams by causing water bodies imbalance [59].
Substitution of stone washing by enzymatic washing raising the environmental issues
has taken worldwide fame where since last decade do most of the finishing laundries
have been switched to bio-washing [60]. Hence for bio-stoning, an ideal cellulase
should have some exposed site capable of binding with indigo dye with controlled
or minimum back staining especially during white/blue contrasts are supposed to
appear with no post-wash bleaching steps [61].
3.1.6 Bio-polishing
It is an optional process necessary for superior quality brightness, lessen pilling,
soothing of fabric and softener feel of fabric surface is a finishing or bio-polishing
process because most of the cotton fabrics or its blends become dull and fluffy after
continuous wet processing [20, 56]. However, the cotton fabric itself tends to form
a pilling as well as fuzz formation [25]. Therefore permanent removal of pilling or
fuzz is required to enhance the market values of cotton fabric [62]. The family of
cellulases used for the bio-polishing process is (i) endo-cellulases (ii) exo-cellulases
(iii) β-glucosidase (iv) cellulose phosphorylases (v) oxidative cellulases, which are
commonly utilized for hydrolyzing micro-fibrils of cellulose that gives a glossier and
smoother appearance to fabric [55, 63, 64]. The tendency of cotton clothes to form
fuzz has been much reduced and has become more fragile after bio-polishing [51,
65]. Other benefits of bio-polishing include:
(i) improvement in breaking strength
(ii) improves elongation [43]
(iii) reduce rugosity [50]
(iv) reduce energy and water consumptions [46, 47]
(v) don’t need any chemical coating [66]
(vi) eco-friendly process [67]
(vii) Generally, bio-polishing is performed after bleaching and pre-treatment are
necessary for inductions of enzyme attack that becomes minimum due to
packing [44].
Cellulases in bio-polishing produce substantial changes in structure that improve
consequent chemical processes [43, 44, 68]. Kan and Au [69] reported that biopolishing and UV-absorber treatment act synergistically. The degree of surface disruption is directly proportional to the binding capacity of cellulase with crystalline
and insoluble cellulose [70]. Cellulase extracted from thermophile T. maritime didn’t
influence the surface of cotton fabric, indicating maximum hydrolytic activity with
soluble cellulose [71]. In contrary to this, endoglucanase (EG-II) and cellobiohydrolase (CBH-I) extracted from T. reesei disrupt the surface of cotton fabric when
worked simultaneously [70].
Bio-polishing is always performed during treatments like jets and rotating drum
washers in which fabric is supplied with strong mechanical agitation. The balance
93
stone washing produces large amounts of sludge approximately 18 metric tons per
weak which clog up the wastewater streams by causing water bodies imbalance [59].
Substitution of stone washing by enzymatic washing raising the environmental issues
has taken worldwide fame where since last decade do most of the finishing laundries
have been switched to bio-washing [60]. Hence for bio-stoning, an ideal cellulase
should have some exposed site capable of binding with indigo dye with controlled
or minimum back staining especially during white/blue contrasts are supposed to
appear with no post-wash bleaching steps [61].
3.1.6 Bio-polishing
It is an optional process necessary for superior quality brightness, lessen pilling,
soothing of fabric and softener feel of fabric surface is a finishing or bio-polishing
process because most of the cotton fabrics or its blends become dull and fluffy after
continuous wet processing [20, 56]. However, the cotton fabric itself tends to form
a pilling as well as fuzz formation [25]. Therefore permanent removal of pilling or
fuzz is required to enhance the market values of cotton fabric [62]. The family of
cellulases used for the bio-polishing process is (i) endo-cellulases (ii) exo-cellulases
(iii) β-glucosidase (iv) cellulose phosphorylases (v) oxidative cellulases, which are
commonly utilized for hydrolyzing micro-fibrils of cellulose that gives a glossier and
smoother appearance to fabric [55, 63, 64]. The tendency of cotton clothes to form
fuzz has been much reduced and has become more fragile after bio-polishing [51,
65]. Other benefits of bio-polishing include:
(i) improvement in breaking strength
(ii) improves elongation [43]
(iii) reduce rugosity [50]
(iv) reduce energy and water consumptions [46, 47]
(v) don’t need any chemical coating [66]
(vi) eco-friendly process [67]
(vii) Generally, bio-polishing is performed after bleaching and pre-treatment are
necessary for inductions of enzyme attack that becomes minimum due to
packing [44].
Cellulases in bio-polishing produce substantial changes in structure that improve
consequent chemical processes [43, 44, 68]. Kan and Au [69] reported that biopolishing and UV-absorber treatment act synergistically. The degree of surface disruption is directly proportional to the binding capacity of cellulase with crystalline
and insoluble cellulose [70]. Cellulase extracted from thermophile T. maritime didn’t
influence the surface of cotton fabric, indicating maximum hydrolytic activity with
soluble cellulose [71]. In contrary to this, endoglucanase (EG-II) and cellobiohydrolase (CBH-I) extracted from T. reesei disrupt the surface of cotton fabric when
worked simultaneously [70].
Bio-polishing is always performed during treatments like jets and rotating drum
washers in which fabric is supplied with strong mechanical agitation. The balance