Algae, Tree, Herbs, Bush, Shrub, Grasses, Vines, Fern, Moss, Spermatophyta, Bryophyta, Fern Ally, Flower, Photosynthesis, Eukaryote, Prokaryote, carbohydrate, vitamins, amino acids, botany, lipids, proteins, cell, cell wall, biotechnology, metabolities, enzymes, agriculture, horticulture, agronomy, bryology, plaleobotany, phytochemistry, enthnobotany, anatomy, ecology, plant breeding, ecology, genetics, chlorophyll, chloroplast, gymnosperms, sporophytes, spores, seed, pollination, pollen, agriculture, horticulture, taxanomy, fungi, molecular biology, biochemistry, bioinfomatics, microbiology, fertilizers, insecticides, pesticides, herbicides, plant growth regulators, medicinal plants, herbal medicines, chemistry, cytogenetics, bryology, ethnobotany, plant pathology, methodolgy, research institutes, scientific journals, companies, farmer, scientists, plant nutrition
Select Language:
 
 
 
 
Main Menu
Please click the main subject to get the list of sub-categories
 
Services offered
 
 
 
 
  Section: General Biotechnology / Microbial Biotechnology
 
 
Please share with your friends:  
 
 

Enzyme Technology

 
     
 

Applications of Enzymes

The biocatalysts (enzymes and cells) are used in multifarious ways in different field. Trevan (1987) has grouped the applications into four broad categories: (i) therapeutic uses, (ii) analytical uses, (iii) manipulative uses, and (iv) industrial uses.

 

Therapeutic Uses

Enzymes are used for this purpose where some inborn errors of metabolism occur due to missing of enzyme (see Monoclonal antibodies) where specific genes are introduced to encode specific missing enzymes. However, in most of cases certain diseases are treated by administering the appropriate enzyme. For example, virilization of a disease developed due to loss of an hydroxylase enzyme from adrenal cortex and introduction of hydroxyl group (-OH) on 21-carbon of ring structure of steroid hormone. Steroids are compounds having a common skeleton in the form of perhydro-1, 2-cyclo-pentano-phenanthrene (Fig. 17.4). The missing enzyme synthesizes aldosterone (male hormone) in excess leading to masculinization of female baby and precocious sexual activity in males in about 5-7 years.

 

Similarly, treatment of leukaemia (a disease in which leukaemic cells require exogenous asparagine for their growth) could be done by administering asparaginase of bacterial origin.

 

Analytical Uses

Use of enzymes for analytical purposes is also important. Gen­erally end point and kinetic analysis are pos­sible. End point analysis refers to total conver­sion of substrates into products in the presence of enzymes in a few minutes while kinetic analysis involves the rate of reaction and sub­strate/product concentration. Moreover, analy­sis of antibodies, immunoglobins, necessary for human use poses a great promise. The usable enzymes are alkaline phosphatase, b-galactosidase, b-lactamase, etc.

A common skeleton of the steroids

Fig. 17.4. A common skeleton of the steroids

 

Content

Microorganisms

Properties of enzymes

 

Presence of species specificity

 

Variation in activity and stability

 

Substrate specificity

 

Activation and inhibition

Methods of enzyme production

 

Isolation of microorganisms, strain development and preparation of inoculum 

 

Medium formulation and preparation

 

Sterilization and inoculation of medium, maintenance of culture and fluid filtration

 

Purification of enzymes

Immobilization of enzymes

 

Advantages of using immobilized enzymes

 

Methods of enzyme immobilization

 

 

Adsorption

 

 

Covalent bonding (Ionic bonding)

 

 

Entrapping

 

 

Cross linking

 

 

Encapsulation

 

Effects of enzyme immobilization on enzyme stability

Enzyme engineering

Application of enzymes

 

Therapeutic uses

 

Analytical uses

 

Manipulative uses

 

Industrial uses

 

 

In dairy industry

 

 

In detergent industry

 

 

In starch industry

 

 

In brewing industry

 

 

In wine industry

 

 

In pharmaceutical industry

Biosensor

 

Types of biosensor

 

Applications of biosensor

Biochips

 

Principles of Biochips

 

Application of Biochips

Another use of enzyme is in biosensor, device of biologically active material displaying characteristic specificity with chemical or electronic sensor to convert a biological compound into an electronic signal. It is constructed to measure almost anything from blood glucose. A simple carbon electrode, an ion sensitive electrode, oxygen electrode or a photocell, may be a sensor (Trevan, 1987).

 

Manipulative Uses

A variety of enzymes isolated from different sources are now-a-days applied in genetic engineering as one of the biological tools. Some of them are available in market (Table 3.1). Examples and brief discussion of these enzymes are given in Example of some enzymes.

 

Industrial Uses

Enzymes are used in industries in different ways.

 

In dairy industry

For a long time calf rennet has been used in dairy industry. In recent years, calf rennets are replaced by microbial rennets (e.g. Mucor michei). They are acid aspartate proteases. They slightly differ from calf rennets as they depend for reaction with casein on Ca++, temperature, pH, etc.

 

Lactase (produced by Bacillus stearothermophilus) is used for hydrolysis of lactose in whey or milk, and lipase for flavor development in special cheeses.

In detergent industry

During normal washing proteinaceous dirt often precipitates on solid cloths and proteins facilitate to adhere the dirt on textile fibers and make stains on cloths. These stains are difficult to remove from clothes. Nevertheless, it can be easily removed by adding proteolytic enzymes to the detergent. It attacks on peptide bonds and therefore, dissolves protein. The alkaline serine protease obtained from B. licheniformis is most widely preferred to use in detergent. In addition, the serine protease of B. amyloliquefaciens is also used for this purpose. It contains a-amylase, hence to some extent it may be advantageous (Aunstrup et al., 1979).


In starch industry
It has been mentioned earlier that hydrolysis of starch began in early 1960s to prepare dextrose and glucose syrups. Furthermore, for complete acid hydrolysis of starch to dextrose glucoamylase was coupled with bacterial a-amylase. Currently, various enzymatic processes are applied for various products (Fig. 17.5).

Glucose isomerase is an important enzyme used commercially in conversion of glucose to fructose via isomerization. Fructose is used in the preparation of fructose syrup.

  Enzymatic process applied in starch industry
 

Fig. 17.5. Enzymatic process applied in starch industry


The reaction mixture at the end contains 42% fructose, 52% glucose and 6% dextrins. The mixture is sweeter than glucose and as sweet as sucrose. Now, techniques have been developed to obtain 55% fructose concentration in syrup (Singh, 1987).

 

In brewing industry

Enzymes used in brewing industry are a-amylase, b-glucanase and protease which are required for malt in substitution of barley. Source of these enzymes is B. amyloliquefaciens. a-amylase is not required for liquefaction or brewing adjuncts and b-glucanase alleviates filtration problems due to poor malt quality and neutral protease helps in the inhibition of alkaline protease by an inhibitor.

 

In wine industry

Pectic enzymes are used in wine industry for high yield of products of improved quality. The pectic enzymes are pectin transeliminase (PTE), polymethyl galacturonase (PMG), polygalacturonase (PG),pectine esterase (PE), etc. However, pectic enzymes give a good result when combined with other enzymes e.g. protease glucoamylase, etc.

  glucose isomerase.....fructose


In pharmaceutical industry

Penicillin G/V acylase, glucose isomerase, etc. are widely used in Pharmaceuticals for the production of semisynthetic penicillins and fructose syrup, respectively. All penicillins consist of an active beta lactam ring i.e. 6-amine penillanic acid (6 APA) group combined with different side chains (R group) (Fig. 16.2) Penicillin G/V acylase removes G/V group from penicillin G/V resulting in separation of 6 APA and R groups.


Finally, new synthetic side chains are coupled with 6 APA to synthesize new semisynthetic penicillins. Enzyme reaction are as below:

 

penicillin G acylase

 

Penicillin G

 arrow

6APA + G side chain

 

penicillin V acylase

 

Penicillin V

Arrow 

6APA + V side chain

 

side chain addition

 

6APA

 arow

semisynthetic penicillins


Among penicillin G acylase producing microorganisms, E. coli strains are the most explored and exploited ones. The biosynthesis of penicillin acylase in E. coli is controlled by altering the nutrients and culture conditions. Sudhakaran and Berkar (1989) investigated the effect of growth substrate, inducers and regulators on enzyme formation. E. coli NCJM-2400 produced penicillin G acylase intracellularly when grown in nutrient broth containing phenyl acetic acid (PAA). PAA (20 mM) stimulatd enzyme synthesis by 8-10 fold. Glucose, lactose, sorbitol, acetate and lactate (all 0.1%) catabolically repressed the enzyme formation. Phosphate and yeast extract were found essential for both the growth and enzyme biosynthesis. Penicillin V acylase occurs in fungal and actinomycetes sources. However, its activity has been found in many bacteria such as Bacillus sphaericus, Erwinia aroideae, and Pseudomonas acidovorans. Lowe et al (1986) have identified a strain of Fusarium oxysporum which showed intracellular penicillin V acylase activity. Activity was induced by phenoxyacetic acid in culture. Enzyme was partially purified and concentrated from disrupted cells (cells hydrolyzed with 5% penicillin V solutions) by fractional precipitation with miscible solvents.

 

 
     
 
 
     



     
 
Copyrights 2012 © Biocyclopedia.com | Disclaimer