1.
Bio-processing of
Textiles

2.
Enzymes, what are they?
A biomolecule which acts as a catalyst.
Catalyst, is to carry out
reactions faster, increase the
efficiency of reaction at a given
condition or bring down the
conditions of the reactions,, but
they are biological catalysts

3.
They are very specific in their action unlike say organic or inorganic or organometallic
catalyst, these are very specific.
Specificity

4.
Structure of enzyme:
 Primary structure
Enzymes are made up of different amino acids which are linked together via
peptide bond in a linear chain.
 The sequence in which the amino acids are arranged are different for
different enzyme.
These sequence of armament of amino acids are genetically decided
So different enzyme has different primary structure
Secondary structure
α-helix, spiral structure
 β-sheet
Tertiary structure
Quaternary structure

5.
Enzyme optimization parameters:
pH
Temperature
Concentration
Important optimization parameters are pH, because pH can change the
ionic character? If ionic character changes, then the tertiary structure can
be stabilized, but may not be exactly the same thing and so it may not
function. So that means, you must know for a particular enzyme, there is
range of a pH in which it is going to be effective. If this structure gets
disturbed, enzyme gets deactivated.
The other optimizing parameter is temperature. Because temperature
means kinetic energy, means more vibrations. If you have more vibrations,
then what happens? This loosely stabilized structure will get destabilized
and so it will not be effective,
For better result you have to use a optimum concentration.
For effective bio reactions, we will have to optimize the pH,
temperature and concentration for specific enzyme.

6.
Enzymes in textile processing
Enzyme Application in textile processing
Cellulase Bio-singeing, Bio-polishing, Denim washing, Bio-
washing
Amylase Bio-desizing
Pectinase Bio-scouring
Protease, like papine,
pepsin
Silk degumming
Catalases,
amyloglucosidases,
pectinases, glucose
oxidases
Bio-bleaching
Proteases and lipases Detergency action
Esterases Polyester finishing
Nitrilases Acrylic finising

7.
Enzymes in textile processing:
Enzymatic singeing or Bio-singeing
Enzyme used: Cellulase enzyme
• Better reflection of light
• Since the protruding fibres are removed the number of contact points of fibre to skin
are lessened, hence the feel is much softer.
• Due to the fact that these protruding fibres or short fibres are immature fibres their dye
uptake or water uptake is comparatively poor hence when they are removed these
characters improves significantly.
• These immature fibres doesn't have desired bending rigidity, hence with little force
they tend to bend and form pills. With their removal pilling is reduced.
• The short fibres when removed, the fibre turns more fluffier, and due to their removal
the inter fibre friction is affected. Which hampers the bending rigidity of fabric. In turn
the fabric turns limpier.

8.
Chemically, cotton cellulose is a polymer of D-glucose in
which individual glucose units are joined by β-1,4glycosidic
linkages, forming a long unbranched polymer with a high
degree of polymerization.
Cellulase enzymes breaks the β (1-4) linkage as shown in fig below, thus breaking the cellobiose unit.
Same process is used for Denim and bio-wash as well where now a days instead of stone washing,
enzymes are used.
Mechanism of action cellulase enzymes:

9.
β-(1,4)-glucosidase
The cellobiose and other small oligomers are then hydrolysed by the third
enzyme, β-(1,4)-glucosidase into glucose.
Exo-β-(1,4)-gluconases (also termed as cellobiohydrolases)
Generated chain ends are further hydrolyzed by Exo-β-(1,4)-gluconases and
produce cellubiose units
Endo-β-(1,4)-gluconase or endo-cellulase
hydrolyse cellulose chain molecules randomly, preferentially attacking the
internal regions of the polymer. They generate more chain ends
The cellulases consist of at least three enzyme systems working synergistically together.
Mechanism of action of cellulase enzymes: Cont……

10.
Acid cellulases exhibit the greatest activity generally in the
pH range 4.5-5.5
 Temperature 45-55°C,
Whereas neutral cellulases require a range
pH of 5.5-8.0 and
Temperature: 50-60°C.
Generally a treatment of 45-120 minutes is appropriate, as prolonged treatment
time may increase the fibre loss significantly.
Optimum process condition: