Montega Uno - Chemistry - Fundamentals of enzymes

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FUNDAMENTALS OF ENZYMES

INDEX What enzymes are? How enzymes work? Are enzymes alive? Applications of enzymes in detergency Applications of enzymes in the textile
	Amylase Lipase Laccase Catalase Cellulase

What are enzymes?

Enzymes are large protein molecules made up of long chains of amino acids. They behave as catalysts toward some reaction that are essential for life in nature. Enzymes are produced by living cells in plants and animals, but they are also secreted by microorganisms, as bacteria or fungi, in way to degrade a substrate into nutritional substances.

Examples of such natural processes can be found everywhere. Some fungi that grow on wood secrete cellulase: an enzyme able to degrade the cellulose of wood into glucose, which represents the source of life of the fungi. In the human digesting apparatus cellulases are not present, and therefore wood cannot be included in our menu. In the other hand, our body provides amylase enzyme, which that break chains of starch into sugars, making therefore possible to us eat rice and pasta and use them as a source of nourishment.

How enzymes work?

Enzymes, differently from ordinary chemical substances, do not participate directly to the reaction as reagents, but rather they act as catalysts, lowering the amount of energy required to make a reaction happen.
This has some important consequences.

1 - At the end of the reaction the enzyme is still intact, and therefore it can continue to attack the substrate.
2 - Due to the previous point, the dosages of enzymes required to attack a substrate are very low.
3 - The reaction proceeds very fast in presence of a specific enzyme.

Comparing chemical and enzymatic reactions, enzymes exhibit a series of interesting characteristics and advantages, which can be resumed as follow:

	Enzymatic Reactions	Chemical Reactions
Substrate attacked	Enzymes are very selective, and they are active only on one specific substrate	Chemical substances are not selective, and they may attack more than just one substrate
At the end of the reaction:	Enzymes are not consumed (they act as catalysts)	Reagents are consumed during a reaction
Dosages required:	Due to the above point, very low	Due to the above point, typically high
Environmental impact:	Very low to none at all (amounts required in the industrial processes are very limited. Moreover, enzymes are readily biodegradable)	It can be strong and detrimental (amounts involved in the industrial processes are usually high, and many substances can be harmful for the environment if processed in a improper way)

Under a chemical point of view, what makes enzymes extremely interesting is their ability to attack a substrate in a very selective way, resulting totally inert toward all the other substances/substrates. The example here below shows how three different enzymes are active only toward one specific substrate.

Under the ecological point of view, enzymes result interesting, for both the small amounts involved in the reactions, and for their high biodegradability.

Are enzymes alive?

No, they are secreted by living organisms, but like all other biochemical substances they are not alive.

Applications of enzymes in detergency

Since most of stains typically found on fabrics are of natural origin, enzymes have started to be included in formulation of detergents in both the form liquid and powder. That resulted in an increased ability in remove stains from clothes and linen. Even under the ecological aspect enzymes in detergents have introduced significant benefits, as lower amount of surfactants are required to reach an established performance.

Enzymes that are more frequently used in detergency are:

Enzyme	Substrate attacked	Kind of soil removed
Amylase	Starch	rice, pasta, potatoes, corn
Protease	Proteinaceous soils	Blood, grass, wine, coffee, tomatoes, etc.
Lipase	Oil and grease soils	Oil, grease

Application of enzymes in the textile

Since most of the raw materials used in textile industry are natural, new enzymatic formulations have greatly grown and expanded in the market of the industrial treatment of the fabrics over the last 10 years.

Enzyme	Substrate attacked	Industrial Applications
Amylase	Starch	Desizing of raw cotton garments
Cellulase	Cellulose (cotton)	Stone Wash - Biopolishing - Biofinishing
Lipase	Greases, waxes	Desizing processes
Laccase	Indigo color	Improvement of the image of denim's garments
Catalase	Peroxydes	Removal of peroxydes in dyeing processes

Amylase

an amylase enzyme
(3d CG Model)

Amylase are used to remove the starch size from the fabrics before other treatments. An efficient removal of the starch from the fabric is essential to enhance the performances of other products by facilitating as much as possible the contact between the liquor and the fibers. Actually, there are two main kinds of amylase that differ each other by the range of temperature in which they can operate.

Lipase: they are used to remove the size from the fabrics together with amylase when the size is a blend of starches mixed with waxes.

Catalase

a catalase enzyme
(3d CG Model)

Catalase are used to eliminate hydrogen peroxyde from the bath before the dyeing processes. It allows to skip a rinse of water, renouncing also to the usage of reducing chemical agents as, for example, Sodium bisulphite. The advantages of the treatment with catalases are therefore in term of time saving and lower environmental impact.

Treatment	1 cycle	2 cycle	3 cycle	4 cycle
Chemical	Bleach	Rinse with Sodium Bisulphite or other similar reducing agent	2^° rinse	Dyeing
Enzymatic	Bleach	rinse with a Catalase	Tintura

Laccase : they allow to get outstanding contrasted look on denim fabrics. Laccase improve the global image of the denim fabric eliminating all the negative effects of the indigo dye redeposition. They can also dramatically reduce the time of the processes necessary to achieve a highly abraded look. With laccase it is possible to get a good variety of effects on denim fabrics, which would be impossible to reach in another way. An example is constituted by bleach effects that still keep a good contrast, or also bleaches over fiber that are damaged by traditional aggressive oxidizing agents as Sodium hypochlorite.

Once more, the advantages of the treatment with laccase are related to time saving and their very low environmental impact

Cellulase: le cellulase, due to their versatility, can be used for different purposes:

Biopolishing: cellulases remove imperfections from the surface of the fabric, making clothes look new.

Stone Wash: cellulases abrade the fibers in depth, making the fabric look old (used especially on Denim jeans fabrics).

Biofinishing: cellulases are mainly used to break long cellulosic chains, giving the fabric a very soft touch.

Until few years ago, the cellulases were classified according to the pH where they show the maximum efficiency. Neutral cellulases were more expensive, but produced a better look on denim clothes. In the other hand, the cheaper acid cellulases were used whenever it was required a high aggressiveness with little concern for the loss of contrast.

The above classification remained valid until the cellulases were obtained only by the fermentation of natural microorganisms. Later, enzyme makers started to select new branches of microorganisms able to produce mixtures of cellulases showing better performances and characteristics. Moreover, enzyme producers found the way to enrich the natural mixtures in one of their components, subtracting from them others that were judged not useful for a specific purpose. That gave origin to a wide range of products optimized for different treatments.

Nowadays, enzyme makers are massively employing biotechnology to genetically modify branches of non-pathogen bacteria in way to get extremely specific and high performance cellulases. In despite of what less informed environmentalists can think, genetically modified non-pathogen bacteria may represent a great help for environment.

Actual classification of cellulase-based products may be the following:

	Method of production
Whole Cellulase	Obtained by fermentation of selected natural bacteria or fungi
Modified Cellulase	Obtained by fermentation of selected natural bacteria or fungi, then enriching the mixture with a specific kind of cellulase (ex: endocellulase or exocellulase)
Engineered Cellulase	Obtained by fermentation of non pathogenic, genetically modified, bacteria or fungi