The environment issues associated with textile processing are not new. A large number of chemicals of diverse nature involved in the process may be present as such or converted into other chemicals during processing, leading to effluent that requires definite environmental treatment. Enzymes assisted textile processes are envisaged as environmentally benign alternatives.
What are Enzymes?
Enzymes are present in living organisms and are themselves not living organisms. Structurally they resemble proteins of varying complexity based on chains of amino acids linked by peptide linkage. Each enzyme is different from another enzyme, and this difference is due to:
Amylases
They convert amylose or amylopectin, polymeric substances commonly referred to as starch, into water-soluble shorter-chain sugars. They are isolated from bacteria, fungi, pancreases, and malt.
Lipases
Cotton waxes consist of various hydrocarbons, fatty alcohols, and acids, along with their respective esters. These fats and waxes are the major reasons for the hydrophobic nature of unscoured cotton fiber. Lipases hydrolyze fats and oils into alcohols and organic acids.
Pectinase
Pectinic compounds found in raw cotton mainly consist of neutral and acidic heteropolysaccharides with different molecular weights and degrees of esterification. Pectinases capable of hydrolyzing pectinic substances are generally enzyme complexes containing esterases and depolymerases with random or terminal activities.
Cellulase
Cellulases enhance the effect of pectinase to a certain extent and add softness to the cotton fabric. They often accompany pectinases in small amounts. If used for scouring, cellulases hydrolyze cotton cellulose, lifting off non-cellulosic impurities in the course of the reaction.
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