commercial Enzymes

Historical background

Most of the reactions in living organisms are catalyzed by protein molecules called enzymes. Enzymes can rightly be called the catalytic machinery of living systems. The real break straight through of enzymes occurred with the introduction of microbial proteases into washing powders. The first commercial bacterial Bacillus protease was marketed in 1959 and major detergent manufactures started to use it around 1965.

The Food Pyramid

The commercial enzyme producers sell enzymes for a wide range of applications. The estimated value of world store is presently about Us$ 2 billion. Detergents (37%), textiles (12%), starch (11%), baking (8%) and animal feed (6%) are the main industries, which use about 75% of industrially produced enzymes.

Enzyme classification

Presently more than 3000 distinct enzymes have been isolated and classified. The enzymes are classified into six major categories based on the nature of the chemical reaction they catalyze:

1. Oxidoreductases catalyze oxidation or allowance of their substrates.

2. Transferases catalyze group transfer.

3. Hydrolases catalyze bond breakage with the increasing of water.

4. Lyases take off groups from their substrates.

5. Isomerases catalyze intramolecular rearrangements.

6. Ligases catalyze the joining of two molecules at the charge of chemical energy.

Only a small number of all the known enzymes are commercially ready . More than 75 % of commercial enzymes are hydrolases. Protein-degrading enzymes constitute about 40 % of all enzyme sales. More than fifty commercial commercial enzymes are ready and their number is increasing steadily.

Enzyme production

Some enzymes still extracted from animal and plant tissues. Enzymes such as papain, bromelain and ficin and other speciallity enzymes like lipoxygenase are derived from plants and enzymes pepsin and rennin are derived from animal. Most of the enzymes are produced by microorganisms in submerged cultures in large reactors called fermentors. The enzyme production process can be divided into following phases:

1. Option of an enzyme.

2. Option of production strain.

3. Building of an overproducing stain by genetic engineering.

4. Optimization of culture medium and production condition.

5. Optimization of rescue process.

6. Formulation of a carport enzyme product.

Criteria used in the Option of an commercial enzyme contain specificity, reaction rate, pH and temperature optima and stability, succeed of inhibitors and affinity to substrates. Enzymes used in the commercial applications must regularly tolerant against various heavy metals and have no need for cofactors.

Microbial production strains

In selecting the production strain several aspects have to be considered. Ideally the enzyme is secreted from the cell. Secondly, the production host should have a Gras-status. Thirdly, the organism should be able to produce high number of the desired enzyme in a inexpensive life time frame. Most of the industrially used microorganism have been genetically modified to overproduce the desired operation and not to produce undesired side activities.

Enzyme production by microbial fermentation

Once the biological production organism has been genetically engineered to overproduce the desired products, a production process has to be developed. The optimization of a fermentation process includes media composition, cultivation type and process conditions. The large volume commercial enzymes are produced in 50 -500 m3 fermentors. The extracellular enzymes are often recovered after cell extraction (by vacuum drum filtration, separators or microfiltration) by ultrafiltration.

Protein engineering

Often enzymes do not have the desired properties for an commercial application. One Option is find a good enzyme from nature. Another Option is to engineer a commercially ready enzyme to be a good commercial catalyst. Another Option is to engineer a commercially ready enzyme to be a good commercial catalyst. Two distinct methods are presently available: a random method called directed evaluation and a protein engineering method called rational design.

Enzyme technology

This field deals with how are the enzymes used and applied in practical processes. The simplest way is to use enzymes is to add them into a process stream where they catalyze the desired reaction and are gently inactivated while the process. This happens in many bulk enzyme applications and the price of the enzymes must be low to take their use economical.

An alternative way to use enzymes is to immobilize them so that they can be reused. Enzyme can be immobilized by using ultra filtration membranes in the reactor system. The large enzyme molecule cannot pass straight through the membrane but the small molecular reaction products can. Many distinct laboratory methods for enzyme immobilization based on chemical reaction, entrapment, specific binding or absorption have been developed.

Large scale Enzyme applications

1] Detergents

Bacterial proteinases are still the most foremost detergent enzymes. Lipases decompose fats into more water-soluble compounds. Amylases are used in detergents to take off starch based stains.

2] Starch hydrolysis and fructose production

The use of starch degrading enzymes was the first large scale application of microbial enzymes in food industry. In general two enzymes carry out conversion of starch to glucose: alpha-amylase and fungal enzymes. Fructose produced from sucrose as a starting material. Sucrose is split by invertase into glucose and fructose, fructose separated and crystallized.

3] Drinks

Enzymes have many applications in drink industry. Lactase splits milk-sugar lactose into glucose and galactose. This process is used for milk products that are consumed by lactose intolerant consumers. increasing of pectinase, xylanase and cellulase heighten the liberation of the juice from pulp. Similarly enzymes are widely used in wine production.

4] Textiles

The use of enzymes in textile manufactures is one of the most rapidly growing fields in commercial enzymology. The enzymes used in the textile field are amylases, catalase, and lactases which are used to take off the starch, degrade excess hydrogen peroxide, bleach textiles and degrade lignin.

5] Animal feed

Addition of xylanase to wheat-based broiler feed has increased the ready metabolizable energy 7-10% in various studies. Enzyme increasing reduces viscosity, which increases absorption of nutrients, liberates nutrients whether by hydrolysis of non-degradable fibers or by liberating nutrients blocked by these fibers, and reduces the number of faeces.

6] Baking

Alpha-amylases have been most widely studied in association with improved bread ability and increased shelf life. Use of xylanases decreases the water absorption and thus reduces the number of added water needed in baking. This leads to more carport dough. Proteinases can be added to heighten dough-handling properties; glucose oxidase has been used to replace chemical oxidants and lipases to develop gluten, which leads to more carport dough and good bread quality.

7] Pulp and Paper

The major application is the use of xylanases in pulp bleaching. This reduces considerably the need for chlorine based bleaching chemicals. In paper development amylase enzymes are used especially in modification of starch. Pitch is a sticky substance present In general in softwoods. Pitch causes problems in paper machines and can be removed by lipases.

8] Leather

Leather manufactures uses proteolytic and lipolytic enzymes in leather processing. Enzymes are used to take off unwanted parts. In dehairing and dewooling phases bacterial proteases enzymes are used to sustain the alkaline chemical process. This results in a more environmentally cordial process and improves the ability of the leather . Bacterial and fungal enzymes are used to make the leather soft and easier to dye.

9] Speciality enzymes

There are a large number of specialty applications for enzymes. These contain use of enzymes in analytical applications, flavour production, protein modification, and personal care products, Dna-technology and in fine chemical production.

10] Enzymes in analytics

Enzymes are widely used in the clinical analytical methodology. Contrary to bulk commercial enzymes these enzymes need to be free from side activities. This means that explain purification processes are needed.

An foremost amelioration in analytical chemistry is biosensors. The most widely used application is a glucose biosensor fascinating glucose oxidase catalysed reaction.

Several commercial instruments are ready which apply this principle for measurement of molecules like glucose, lactate, lactose, sucrose, ethanol, methanol, cholesterol and some amino acids.

11] Enzymes in personal care products

Personal care products are a relatively new area for enzymes. Proteinase and lipase containing enzyme solutions are used for contact lens cleaning. Hydrogen peroxide is used in disinfections of contact lenses. The residual hydrogen peroxide after disinfections can be removed by catalase enzyme. Some toothpaste contains glucoamylase and glucose oxidase. Enzymes are also studied for applications in skin and hair care products.

12] Enzymes in Dna-technology

Dna-technology is an foremost tool in enzyme industry. Most primary enzymes are produced by organisms, which have been genetically modified to overproduce the desired enzyme. The specific order of the organic bases in the chain of Dna constitutes the genetic language. Genetic engineering means reading and modifying this language. Enzymes are crucial tools in this process.

13] Enzymes in fine chemical production

In spite of some successes, commercial production of chemicals by living cells using pathway engineering is still in many cases the best alternative to apply biocatalysis. Isolated enzymes have, however, been successfully used in fine chemical synthesis. Some of the most foremost examples are represented here.

13 A] Chirally pure amino acids and aspartame

Natural amino acids are regularly produced by microbial fermentation. Novel enzymatic resolution methods have been advanced for the production of L- as well as for D-amino acids. Aspartame, the oppressive non-calorie sweetener, is synthesized in non-aqueous conditions by thermolysin, a proteolytic enzyme.

13 B] Rare sugars

Recently enzymatic methods have been advanced to make roughly all D- and L-forms of straightforward sugars. Glucose isomerase is one of the foremost commercial enzymes used in fructose manufacturing.

13 C] Semisynthetic penicillins

Penicillin is produced by genetically modified strains of Penicillium strains. Most of the penicillin is converted by immobilised acylase enzyme to 6-aminopenicillanic acid, which serves as a backbone for many semisynthetic penicillins.

13 D] Lipase based reactions

In increasing to detergent applications lipases can be used in versatile chemical reactions since they are active in organic solvents. Lipases used in transesterification and also used for enantiomeric disjunction of alcohols and separate racemic amine mixtures. Lipases have also been used to form aromatic and aliphatic polymers.

13 E] Enzymatic oligosaccharide synthesis

The chemical synthesis of oligosaccharides is a complicated multi-step effort. Biocatalytic syntheses with isolated enzymes like glycosyltransferases and glycosidases or engineered whole cells are powerful alternatives to chemical methods. Oligosaccharides have found applications in cosmetics, medicines and as functional foods.

Future trends in commercial enzymology

Industrial enzyme store is growing steadily. The suspect for this lies in improved production efficiency resulting in economy enzymes, in new application fields. Tailoring enzymes for specific applications will be a hereafter trend with continuously improving tools and understanding of structure-function relationships and increased quest for enzymes from exotic environments.

New technical tools to use enzymes as crystalline catalysts, ability to recycle cofactors, and engineering enzymes to function in various solvents with many activities are foremost technological developments, which will steadily generate new applications.

commercial Enzymes