*3.1.4 Lipases/Esterases*

Esterases represent a group of hydrolases that catalyse the cleavage of fats, oils and formed ester bonds. They are widely obtained from animals, plants and microorganisms. These enzymes make attractive biocatalysts for the production of

**Figure 7.** *Degradation of protein by proteases.*


#### **Table 6.**

*Protease enzyme from different microorganisms.*

optically pure compounds in fine-chemicals synthesis. Lipases have threedimensional structure with the characteristic α/β-hydrolase fold [83]. The phenomenon of interfacial activation can be distinguished by lipases and esterases. The interfacial activation is due to hydrophobic domain covering the lipase active site and the presence of a substrate concentration will lid open, making the active site accessible. It can be used for elimination of natural triglycerides in scouring and tallow compounds in desizing process [84]. The phytopahthogenic fungus is the best examples of lipases are shown in **Table 7**.

Arylesterase obtained from Bio-bleach system HUNTSMAN and H2O2 in situ generate peracetic acid for mild temperature at 65<sup>o</sup> C, neutral bleaching of cotton [85]. Lipase enzymes perform both bio-scouring and bio-bleaching, which provide high degree of whiteness [86].

## **3.2 Oxidoreductases**

The enzymes catalyze oxido reduction reactions, transfer electrons through substrates like cellulose. In the majority of cases, the substrate that is oxidized is regarded as a hydrogen donor. The systematic name of oxidoreductases is based on donor acceptor groups. The enzymes named oxidase, which contains molecular oxygen (O2) is the acceptor.



#### **Table 7.**

*Lipase enzyme from different microorganisms.*

Oxidoreductases enzymes categorize two nonhydrolytic enzymes such as peroxidase and catalase.

## *3.2.1 Peroxidase/glucose oxidase*

Glucose oxidase or peroxidase acts in the presence of oxygen to convert glucose to gluconic acid and hydrogen peroxide. It can oxidize only β-D-glucose (**Figure 8**).

The galactose oxidase (GO) from *Dactylium deudroides* the oxidation of Dgalactose at the C-6 position in the presence of oxygen to give Dgalactohexodialdose and hydrogen peroxide. The enzyme contains one atom of Cu2+ per molecule as co-factor. Recent investigations indicate that the enzyme catalyses the stereo specific oxidation of glycerol, 3-halogenopropane-1-2-diols and polyols to the corresponding aldehydes (**Figure 9**).

Peroxidase is synthesized in several species of fungi and bacteria are illustrated in **Table 8**.

Glucose-Oxidase desize cotton fabric and enzymatically produce peroxide for bleaching at elevated temperature with high pH [87]. Combined glucose, glucoseoxidase & peroxidase for cotton bleaching [88]. Glucose-oxidase (Commercial Novo Nordisk- Denmark) optimized bio-bleaching of cotton, linen and their blends with 25 U/ml GOE, 10 g/l D-glucose at 85<sup>o</sup> C & pH 10 for 90 min [89]. Glucose-

$$\begin{array}{ccccc} \mathsf{C\_6H\_{12}O\_6} + \mathsf{O\_2} + \mathsf{H\_2O} & \begin{array}{c} \text{glucose oxidase} \\ \hline \end{array} & \begin{array}{c} \mathsf{C\_6H\_{12}O\_7} \\ \hline \end{array} \star \begin{array}{c} \mathsf{O\_2H\_{12}O\_7} \\ \hline \end{array} + \begin{array}{c} \mathsf{H\_2O\_7} \\ \hline \end{array} \end{array}$$

#### **Figure 8.**

*Degradation of glucose-by-glucose oxidase.*

#### **Figure 9.**

*Degradation of D-galactose by galactose oxidase.*


#### **Table 8.**

*Peroxidase enzyme from different microorganisms.*

*Sustainable Textile Processing by Enzyme Applications DOI: http://dx.doi.org/10.5772/intechopen.97198*

Oxidase (*Aspergillus niger*) Biozyme with pullanase mixture used for sufficient (800 mg/l) H2O2 for bleaching and maximum whiteness obtained in alkaline pH compared to neutral and acidic pH [90]. Glucose-oxidase from (*Aspergillus niger*) with external oxygen supply and mechanical agitation essential for H2O2 generation cotton bleached at room temperature & acidic pH with high enzyme concentration [91]. 6% increase in whiteness index with comparable mechanical properties using peroxide produced by glucose oxidase [92]. One bath low temperature of cotton pretreatment by glucose oxidase where liberated H2O2 converted to peracetic acid using TAED as activator [93]. Glucose-Oxidase GC 199 combine desizing, scouring with enzymes followed by bleaching with in-situ generated peracetic acid using different activators [94]. Assistance of ultrasound with glucose-oxidase improves whiteness due to increase enzyme reaction at 90<sup>o</sup> C with pH 11 [95]. Multifect GO 5000 L, Genecor performed desizing, bleaching and reactive dyeing for cotton towel [96]. Glucose-oxidase from *Aspergillus niger* immobilized on porous carriersglass & alumina, low enzyme concentration provides sufficient H2O2 release which further activated for textile bleaching [97].

#### *3.2.2 Catalases*

Catalases (CATs) also known as hydroperoxidases, catalyse the degradation of H2O2 to H2O and O2. Catalase, which is also found in commercial fungal glucose oxidase preparations [98] (**Figure 10**).

Catalases are ubiquitous oxidoreductases enzymes present in archaea, bacteria, fungi, plants and most have optimum temperatures (20-50<sup>o</sup> C) and neutral pH. Catalases obtained from animal sources (bovine liver) are generally cheap; therefore, the production of microbial catalase will be economically advantageous when recombinant technology is used. Catalases have special properties such as thermosatbility and operate both in alkaline or acidic pH. The chloroperoxidase from *Caldariomyces fumago* also catalyses the oxidation of halide ions except fluoride (**Table 9**).

Glucose-oxidase (multifect GO 5000 L, Genecor), Catalase (Terminox Ultra 10 L) integrated desizing, bleaching and reactive dyeing of cotton towel was performed [96].

#### **Figure 10.**

*Degradation of hydrogen peroxide by catalase.*


#### **Table 9.**

*Catalases enzyme from different microorganisms.*


#### **Table 10.**

*Laccases enzyme from different microorganisms.*

#### *3.2.3 Laccases*

Laccase originated from blue-multicopper oxidase family. It oxidizes a variety of aromatic and non-aromatic phenolic compound also depolymerizes the substrate by a radical-catalyze reaction mechanism.

Laccases have been found in plants, fungi, insect and bacteria. However, more than 60 fungal strains have found laccase activity. Fungal laccase is a protein approximately 60–70 KDa, which activate in the acidic pH range and optimal temperature between 50 and 70<sup>o</sup> C. Few laccases enzymes activate with optimum temperature below 35<sup>o</sup> C (**Table 10**).

Combined laccase/peroxide bleaching applied in batch & pad dry method [99]. Laccase from *Trametes hirsute* with mediator improve whiteness of cotton due to oxidation of flavonoids [100]. Complex enzyme Laccase & Peroxidase (*Ph Chrysoporium & Trichosporon cutaneum R57)* efficiently degrade & remove lignin from flax fiber to provide whiteness [101]. Laccase, Novozyme obtained from *Trametes villosa* assistance with ultrasound and PVA addition stabilize laccase and improve bleaching [102]. Ecolite II (Commercial Laccase, Jeans are company) and H2O2 performed bleaching of linen allows better dye uptake for both reactive and cationic dyes [103].

#### **4. Textile applications**

The enzymatic textile processing has started in the middle of nineteenth century. The enzymes were introduced in de-sizing purposes for the first time in 1857; however, enzymatic de-sizing process was successfully introduced in 1912 [104]. In addition, cellulases were introduced in 1980s for de-pilling and de-fuzzing of cellulose-based fabrics [105]. In the early 1990s, catalases were entered into the bleaching and pectin-degrading enzymes to replace traditional alkaline scouring [106]. In biotechnological research is underway, around the globe, introduce environmental friendlier strategies for textile processing is extensively to the modern industry. The potential of enzymatic textile processing is illustrated in **Figure 11**.

*Sustainable Textile Processing by Enzyme Applications DOI: http://dx.doi.org/10.5772/intechopen.97198*

#### **Figure 11.**

*Enzymes used in various operations in textile wet processing [107].*
