SECTION 1
Enzymatic Processing of textiles.
Enzymes for cotton textile processing.
Properties of Various Enzymes

SECTION 2
New Trends in Enzymatic Processing
Use of Enzymes in Textile Effluent Treatment.

Properties of Various Enzymes and Its Application in Textile Processing:

Thermostable amylases

Amylases which catalyse starch hydrolysis in the temperature range of 70-110oC and at pH 6.0-6.8.

Conventional amylases

Amylases which catalyse starch hydrolysis in the temperature range of 50-70oC and at pH 6.0-6.8.

Low temperature amylases

Majority of fungal amylases which catalyse starch hydrolysis in the temperature range of 30-70oC and at pH 6.0-6.8.

Cellulases

Cellulases are hydrolase class of enzymes which cleavage 1-4β glucosidic linkage of cellobiose chain or cellulose. The commercially available cellulases are a mixture of enzymes viz., Endogluconases, Exogluconases and Cellobiases, Endogluconases are subclass of celluase enzymes which randomly attack the cellulose enzymes and hyudrolyze the 1-4 β glucosidic linkage of cellobiose chain. Exoglucanases of cello-biohydrolases are again subclass of cellulose enzyme which hydrolyses 1-4 β glucosidic linkage of cellulose to release cellotiose from the cellulose chain and Cellobiases are enzymes whichhydrolyse cellobiose into soluble glucose units. All these three enzymes act synergistically on cellulose to hydrolse them. Among the different classes of commercially available cellulases, following types find major application in textiles.

Acid Cellulases:

Acid cellulases are class of enzymes that act at pH 3.8-5.8 (-optimum 4.5-6) and in the tempereature range of 30-60oC. The low temperature range of 30-60oC and conventional acid cellulases act in the temperature range of 45-60oC.

Neutral Cellulases:

Cellulase enzymes which actr at pH 6.0-7.0 and in the temperature range of 40-55oC are termed as neutral Cellulases.

Pectinases

Pectinases are a mixture of enzymes, which along with other such as cellulose, are widely used in the fruit juice industry. Enzymes in this pectinase group include polygalacturonases, pectin methyl esterase and pectin lyases. These pectinase enzymes act in defferent ways on the pecans, which are found in the primary cell walls of cotton and jute. Pectins are large polysaccharide molecules, made up of chains of galacturonic acid residues.

Proteases

Proteases are Hydlolase class of enzymes, classified based on the source from which it is extracted, optimum temperature of activity. Proteases precisely act on peptide bonds formed by specific amino acids to hydrolyze them. Commercial proteases are available, which can work in different range of pH and temperature. Trypsin (pancreatic), Papain based and alkaline proteases find industrial applications in textiles.

Peroxidases

Peroxidases or Catalases are Oxidoreductase class of enzymes. The perosidase enzyme catalyse the decomposition of hydrogen peroxide in to water and molecular oxygen as illustrate.
2H2O2→2H2O + O2

Catalase is a heam-contaioning enzyme. Thus, in addition to the protein part of the molecule the enzyme contains a non-protein part, which is a derivative of heam and includes the metal iron. Peroxidases effectively degrade the hydrogen peroxide at varied pH between 3 to 9 and in the temperature range 30 -80 °C.

Laccase

Laccases are Oxidoreductase class of enzymes, belonging to bluoxidase- copper metalloenzymes. Lassases are generally active at pH 3-5 and in the optimal temperature range of 30-50oC. They oxidize using molecular oxygen as electron acceptor from the substrate. Their special property of oxidation of indigo pigments is made use of in textile industries