**3. Enzyme classification for textile processing**

Enzymes are biocatalysts, which can speed up the chemical processes [11]. Enzymes activates like other inorganic catalysts such as acids, bases, metals, and metal oxides. The molecule that an enzyme acts on is known as its substrate, which is converted into a product. The original attempt to classify enzymes was done according to different function. The International Commission on Enzymes (EC) was established in 1956 by the International Union of Biochemistry (IUB) in consultation with the International Union of Pure and Applied Chemistry (IUPAC) recommended hundreds of enzymes that had been discovered. The EC classification system is divided into six categories [12]:


In textile industry mainly hydrolases and Oxidoreductases are engage for various enzymatic applications. Most of the enzyme applications in textiles are confined to cotton processing: removal of impurities (desizing, scouring, bleaching); biofinishing to improve appearance; bio-stoning or stone washing of denims to produce the fashionable aged look; bleaching cleanup to remove residual H2O2 before dyeing [13–17]. In addition to that there are efforts to substitute conventional processes of anti-shrinking, anti-pilling wool & degumming of silk with protease enzyme, retting of bast fibers with pectinase or hemicelluloses the several studies have been reported on modification of synthetics using hydrolases class of enzymes to impart hydrophilicity and antistatic properties [18, 19]. Moreover, detergent with the mixture of enzymes to remove varieties of stains in garments laundering [20]. Textile chemical processing is highly chemical intensive, and a variety of complex chemicals & auxiliaries are regularly used. So, mixed color to water causes toxicity for different form of life. It is essential to treat the effluent specially the residual colorants before discharging in environment. Hence, different enzymes employed for the textile effluent treatment containing synthetic dyes as colorants has been used. International Union of Biochemistry and Molecular Biology set up the Enzyme Commission for solving the complexity of and inconsistency in the naming of enzymes. They proposed almost 7000 enzymes; however, 75 are commonly used in the textile industry [21] According to the use of enzymes in textile industries, enzyme can be classified as shown in **Table 2**.
