Enzyme technology is primarily engaged in the production, isolation, purification and use of enzymes either in the soluble or immobilized form, for the benefit of humankind [1]. With the advancements in, recombinant DNA technology, enzyme engineering produces more effective and diverse group of enzymes with useful applications in microbiology, biochemistry, diagnostics, therapeutics, biocatalysis, structural biology etc. [2]. The overall objective of this emerging technology is to produce unique sustainable products with specific function to fulfill the need of growing population [3].

Objectives of enzyme engineering

• Fabrication of high value specific products by superior enzyme

• To yield greater concentration of enzymes.

• Assembly of synthetic drugs, peptides and proteins

• Producing enzymes with unique properties such as ability to function under extreme environmental conditions

• Alteration in enzyme properties to produce the desired function such as kinetic features of enzyme-turnover, thermal stability, enzyme activity in nonaqueous solvent, reaction/substrate specificity, subunit structure etc. [4-7].

Classification of enzymes

Enzymes classification nomenclature comprises of about 4000 enzymes [8]. Given below is a table indicating enzyme classification (Table 1) [9-12].

Table 1: Enzyme classification.

Functional capabilities of enzymes is determined by their structure [13]. Active sites of enzymes are the sites for their substrate specific catalytic function, while the rest of the protein acts as scaffolding [14].

Given below in Table 2 is list of organisms and their relative contribution in the production of commercial enzymes.

Table 2: List of organisms and their relative contribution in enzyme production.

Enzyme production technology

The basic steps taken for enzyme production includes:

1. Organism selection: Selection of organism depends on the ability of microorganism to yield increased concentration of desired enzyme in a short time period with decreased amounts of secondary metabolites [15-21]. Microbial inoculums introduced in sterilized liquid medium for fermentation, providing optimal growth conditions such as pH, temperature, O2 supply, nutrient [22].

2. Isolation and purification of enzyme: Desired enzyme produced may be excreted into the culture medium or may be present within the microbial cells is recovered and purified by cell disruption techniques and downstream processing respectively ensuring minimal loss of enzyme activity [23].

3. Immobilization of enzyme: Immobilization of enzyme is achieved on cellulose, polyacrylamide, starch and beads etc., [24] by the following methods:

• Adsorption: It involves the attachment of enzyme molecule on an inorganic or organic inert solid support such as silica gel, beads or glass, starch, cellulose etc., by forming weak van dar Waals forces or hydrogen bonding. Later enzymes are removed by slight alterations in pH, ionic strength or temperature [25].

• Cross linking: Enzyme can be immobilized by forming crosslinkage to another chemical such as cellulose or glyceraldehydes but it might cause denaturation of enzyme [26].

• Entrapment: Enzymes can be immobilized by physical entrapment inside a mesh, capsule or a gel matrix of an inert material such as gelatin, polyacrylamide gel, starch, collagen, silicone, cellulose and rubber [27].

• Covalent binding: Immobilization of the enzymes by means of covalent bonding with the support providing the strongest enzyme-support interaction [28].

Applications of enzyme technology

Textile industry

• Amylases enzyme is used as softening agents for starched clothes.

• Cellulases is useful for fabric finishing and often used for better dye uptake in cotton [29,30].

Leather industry

• Proteolytic enzymes is used in dehairing of the skin and for softening /plumping of dehaired skin [31].

Detergent industry

• Proteases is efficient in removing protein stains such as grass, blood, egg and human sweat.

• Lipases can easily break down lipid and protein based stains.

• Amylases is efficient in removing starch-based residues.

• Cellulase used in detergent causing restoring fibre smoothness, its original color and softening [32-34].

Pharmaceutical industry

• Pegadamase bovine is employed for SCID treatment .

• Pancreatic enzymes is effective against fat malabsorption in HIV patients.

• Spinal injuries could be treated with chondroitinases .

• Hyaluronidase aids in the rebuilding of damaged nerve tissues.

• Lysozyme is used as an antibacterial agent and also possess activity against HIV.

• Human melanoma and hepatocellular carcinomas could be inhibited by PEGylated arginine deaminase [35-40].

Food industry

• Amylase is added to the dough to ensure its quality and increased shelf life.

• Enzymes is also employed in cheese making by milk coagulation.

• Proteolytic enzyme help to increase the shelf life of meat and sea food.

• Lipases used to control the lipid content of food products.

• Glucose oxidase and catalase are used as food preservative agents.

• Renin is used in the manufacture of cheese.

• Lactase enzymes is applied in the making of ice cream, yoghurt and frozen and invertase in the making of chocolate covered berries and candies.

• Glucose isomerase is used for the production of fructose and high fructose syrups [41-48].

Thus the enzyme technology is an emerging trend in biotechnology which employs the production of diverse functional enzymes for numerous valuable purposes in different areas.