ABSTRACT
The use of enzymes as an aid in fabric stain removal dates back to the early sixties. In those days, chances for sustained enzyme action during fabric washing were rather limited, because washing was performed at relatively elevated temperatures (i.e., around 60°C and higher). Proteolytic enzymes were added mainly with the aim to prevent redeposition of denatured proteins to the fabric. Since then, washing habits have changed. For instance, the washing temperatures were lowered to around 40°C in Europe and the United States due to economic and environmental reasons. This improved the possibilities for the application of other enzymes [1] such as lipases. Although washing systems already contain surfactants to dissolve greasy stains, the need for additional detergency was found to be stronger when the temperature was lowered. Lipases, or lipolytic enzymes in general, can bring about this additional action under proper conditions (e.g., see Ref. 2 for a recent overview). Greasy stains (such as food stains, cosmetics stains like lipstick, and body stains like sebum) usually consist of proteins, lipids, starch, and pigments, requiring the combined action of several enzymes and many other detergent components for optimal stain removal. As a consequence, the application of lipases for greasy stain removal needs to take into account that other enzyme activities are present-apart from the need to optimize lipolytic action in the presence of surfactants. For optimal lipase action in concert with other enzyme activities, tailor-made lipases need to be developed. Protein engineering of lipolytic enzymes, either using random mutagenesis or site-directed methods, provides the facilities to accomplish this objective. Particularly for site-directed methods, the recent advances in our understanding of structural and functional properties of many lipases provide a strong asset in the endeavor to yield optimal lipolytic action in greasy stain removal from fabrics.
