Liquid enzyme preparation and the use thereof

A process of cleaning an article in need thereof comprising the steps of:

• a. diluting a stabilized liquid enzyme prepration comprising a cleaning-active enzyme, a solvent selected from the group consisting of ethylene glycol, propylene glycol, glycerol, and mixtures thereof, and a stabilizer comprising a basic nitrogen compound selected from the group consisting of polyhexamethylene biguanide, a salt of polyhexamethylene biguanide, N,N-bis-(3-aminopropyl)-dodecyl amine, a salt of N,N-bis-(3-aminopropyl)-dodecyl amine, and mixtures thereof with water in a weight ratio of enzyme preparation to water of 1:500 to 1:5000 to form a cleaning solution;
• b. adding to the cleaning solution 0.01to 0.2% by weight, based on the weight of cleaning solution, of a buffer concentrate, wherein the buffer concentrate comprises 3% to 20% by weight or a complexing agent selected from the group consisting of polyphosphates, polyacrylates, and mixture thereof, 3% to 20% by weight of an alkali metal hydroxide selected from the group consisting of sodium hydroxide, potassium hydroxied, and mixtures thereof,5% to 30% by weight of an alkali metal carbonate selected from the group consisting of sodium carbonate, potassium carbonate, and mixtures thereof, and 20% to 80% by weight water, to adjust the pH of the cleaning solution to 7 to 10;
• and
• c. contacting the article with a portion of the cleaning solution to effect cleaning thereof.