In the last two decades, there has been a huge increase in the number of laundry detergents containing enzymes. The race to build the most effective and distinctive detergent brands has led to formulations containing multiple enzymes. Many of the most successful brands now contain two, three or even four different enzyme types.

 

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Enzymes provide the superior cleaning performance needed to attack stains. Generally, the earliest enzymes to be added to laundry detergents were proteases. However, in today's dynamic marketplace, the most successful detergent brands sometimes combine proteases with amylases, lipases and cellulases to deliver outstanding cleaning performance.

Each of these enzymes is able to attack a specific type of stain or soil. Accordingly, the inclusion of multiple enzymes in a detergent allows the product to tackle a much broader profile of soil types. What's more, multiple enzymes can work in concert to remove tough stains or soils made up of a variety of substances. For example, a food stain might typically contain protein, lipid (fat) and starch, necessitating the combined actions of protease, lipase and amylase for its complete elimination.

More enzymes simply mean a cleaner wash and whiter whites, both long-standing key consumer demands.

But there are other benefits for the consumer too. By their very nature, enzymes are highly energy-efficient molecules. The enzyme action ensures that, even in a short wash cycle, clothes are thoroughly cleaned. Now enzymes can help to eliminate the number one consumer complaint — the need for repeated washes — by working to remove those stubborn fatty food stains in the first wash.

And there's more good news: heavily soiled items don't necessarily need a hot wash any more. A unique feature of enzyme detergents is that they allow the consumer to reduce household energy bills by lowering the washing temperature without jeopardizing cleaning performance. It's therefore not surprising that the widespread inclusion of enzymes in laundry detergents in large parts of Europe and North America has already brought about a broad shift to lower washing temperatures in these areas.

Optimizing the Formula

Novozymes, a biotech company that supplies more than 600 products in industries ranging from food to clothing, strives to help various brands get the blend of enzymes in their laundry detergent just right. In Novozymes' specially equipped in-house laboratories, the technical service team conducts rigorous wash trials to optimize the dose and types of enzyme to be added to basic detergent formulations.

Claus Ladefoged of Novozymes' detergent technical service team explains why including multiple enzymes in a laundry detergent helps to further improve cleaning performance: "As we increase the concentration of an enzyme in a single-enzyme detergent, the cleaning performance improves, but this ultimately reaches a maximum performance plateau beyond which no additional benefit is seen. At this point, cleaning performance can only be further improved by adding new enzymes to the detergent formulation," he says.

Of course, the particular blend of enzymes that the team recommends varies because geographical differences in washing conditions such as water temperature and hardness influence the activity of the enzymes. But because Novozymes' customers sell laundry detergents to consumers in so many different countries, the technical service team has the knowledge and equipment to precisely reproduce washing practices from around the globe.

All About Enzymes — Getting Technical (Info below and photo courtesy of Novozymes)

Enzymes are proteins that are found in every living organism: man, animals, plants and microorganisms. Nature — including human digestive systems — relies on enzymes to break down proteins, starches and fats. The same types of enzymes can be used in detergents to break down the stains that bind to fabrics.

While nature provides an amazing diversity of enzymes, identifying enzyme solutions for a specific problem can be extremely difficult. Most industrial applications place strict demands on the conditions under which an enzyme must operate — pH levels, temperature, and the presence of harsh chemicals all present challenges to enzyme stability and performance.

Massive libraries of enzymes, collected from real-world soil and water samples, are just the beginning of the development process. By utilizing specialized knowledge of protein chemistry and advanced protein engineering, new and improved versions of naturally occurring enzymes can be created. Directed molecular evolution can extend the size of these enzyme libraries into an almost infinite number of protein structures designed to meet the extreme demands of modern industrial processes.

High throughput screening, based on predictive microscreen assays, is used to identify the best enzyme candidates. For instance, Novozymes has developed a technology platform that allows it to scan the capabilities of more than a million enzymes each week. The most promising candidates are then subjected to more complex testing and additional screening to assure a strong correlation between specific microscreen assays and the real-life application. After a specific enzyme has been identified and the relevant genes isolated, an efficient expression system for the enzyme must be developed.

Fermentation to produce industrial enzymes starts with a vial of dried or frozen micro-organisms called a production strain. Industrial enzyme fermentations may use bacteria such as Bacillus, fungi such as Aspergillus or Trichoderma, and the yeast species Saccharomyces cerevisiae. These production organisms have the basic machinery needed to produce large amounts of protein and are non-pathogenic.

Enzyme fermentation is followed by downstream processing, which is the term used to describe the operations performed to transform the fermented product into a purified and concentrated product ready for final formulation. First, the enzyme must be extracted from the fermentation biomass. This is achieved by various chemical treatments of the fermentation broth to ensure efficient extraction, followed by removal of the biomass using either centrifugation or filtration.

Following enzyme extraction, the enzyme is concentrated by means of semi-permeable membranes or evaporation. In the case of products with high purity demands, the downstream process often requires a special step to remove unwanted impurities. This is often done by selective precipitation or adsorption of the impurities, or an advanced crystallization technique by which extremely pure enzyme products can be obtained.

The final step of enzyme production is formulation, which determines the final product form (liquid or dry) and activity (strength) of the enzyme. Further processing to produce enzyme blends and special formulations may also be performed.