Amr El Beleidy

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I’m pretty sure the enzymes they use in washing detergents are optimised for specific temperatures. It’s not necessarily true that washing at 30 means they won’t denature so fast? Quite possibly, but how about go and research the optimal temperature of different detergent enzymes first? I admit I don’t know about them with specifics in washing detergents, however I do remember reading in new scientist how washing detergent researchers were researching enzymes from nature operating in the north pole, where obviously their optimal performance will be at lower temperatures, and hence they can work with them to get better performance from their product at lower temperatures. So it’s not necessarily a steadfast rule that in an average washing detergent, the enzymes in it will work better at 30….

I’m going to go and find the article.

January 3, 2009 5:37 pm

admin

Thank you for that.

I think it is safe to assume that your average detergent is not designed for the north pole. All the detergent advertising that I remember says wash at 30. Talking to friends who worked in the industry, I have come to understand that the enzymes in detergents tend to be selected to work best at 30 degrees.

I am speculating here that maybe what the people in the north pole had trouble with is the enzymes working at all at such low temperatures. Please post a link to the article so we can all have a read. Thanks.

January 4, 2009 1:22 am

Jack

I think in this instant the administrator is missing the point that the poster is trying to make.

Enzymes currently used in detergents operate at a range of temperature from approx. 15 degrees C to 40 degrees C. With much research focused on finding enzymes that have optimum temperatures . With much research focusing on the Psychrophiles genus in deep marine trenches (see Methe B., 2004, Microbial Genomics, DOI: 10.1016/j.tim.2004.10.007) that are infact denatured at temperatures above 20 degress centigrade. The enzymes found in Psychrophilic bacteria already in use. Much research is currently going into the use of enzymes from Psychrophiles that live at much lower temperatures (see Groudieva, 2004, Extremophiles, DOI:10.1007/s00792-004-0409-0) though obviously these enzymes will find little use in household washing powders, since cooling would be necessary to prevent denaturation. The blogger was suggesting that different detergent enzymes may have optimum temperatures far from 30 degrees centigrade (10 degrees either side) this is true, one should always read the packet for the specific product in question rather than washing at 30 degrees by default. Enzymes that have optimums at temperatures close to 15 degrees would be ideal for washing powder use since this is close to the average temperature of tap water (see Lenteche, 2008, url: http://www.lenntech.com/water-recycling.htm) and hence would require little or no heating. This would reduce dramatically the electricity usage during washing.

The blogger also pointed out that enzymes are specifically designed to work at the optimum temperatures set. This is almost true, though enzymes are seldom designed and more frequently harvested from nature where they exist in abundance. It is not therefore unreasonable to imagine that specialist companies may use enzymes with higher optimum temperatures for a white wash or stain removing wash. For example the alkaline protease found in Bacillus cereus and used in washing powders shows high activity at 50 degrees centigrade (see Banik, 2004, Microbiological Research, DOI: 10.1016/j.micres.2004.01.002). So on that point the blogger it appears was entirely correct.

Another point is that denaturation will only occur at higher temperatures, therefore suggesting that washing at thirty reduces denaturation likelihood is technically incorrect. If the person was washing at 25 degrees celsius before then switching to 30 degrees celsius will increase the denaturation likelihood (see any chemical biology textbook from GCSE level onwards). Also the wash at 30 degrees campaign was not a result of a drive to use biological washing powders, due to the inherent allergy risk. It was a campaign started by Ariel which stemmed from the ability of modern non-biological washing powders to disperse more rapidly at lower temperatures and hence emulisfy the residues at lower temperatures. It is still however recommended that higher temperature washes are performed at least weakly to prevent the build up of bacteria in the machine. Terrestrial British bacteria thrive at temperatures of 30 degrees celisus and in damp conditions.

January 8, 2009 8:39 pm

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