Improving stability of a protease in liquid laundry detergents is a multifactorial challenge
Proteases are the most widely used enzymes in the detergent industry. They are performance enablers in detergents and remove protein stains such as grass, blood and egg.
Since the first introduction of proteases into laundry detergents more than a century ago (Burnus by Röhm, 1913, DRP283923) significant progress has been made in engineering, formulation and production of this enzyme class. Beyond superior performance the enzyme needs to be stable within the detergent formulation to guarantee constant performance after storage post production. In this article we present considerations needed to successfully formulate liquid laundry proteases especially when combined with other formulated enzymes. Using the BASF protease Lavergy® Pro 104 L and Lavergy® Pro 104 LS as examples we will show how multiple factors like protein engineering, stabilizers and detergent formulation composition need to be balanced to reach maximum performance in laundry applications.
Proteases are the largest industrial enzyme class and are produced by a wide range of micro-organisms. Proteases are used in a wide variety of industrial applications like detergents, food and feed. Alkaline proteases from bacterial origin, the so-called subtilisins, have the highest market share in home care applications with 58% of all enzyme sales in 2016 (Figure 1).
Alkaline proteases have made significant improvements in performance and stability. Through ongoing modifications, subtilisin have become more intrinsically stable and expand their effectiveness across broader pH and temperature ranges (Kalisz, 2006, Outtrup and Boyce, 1990). The result is subtilisins from various Bacillus species dominate the laundry market and continue to be a key ingredient to meet the increasing performance expectations globally.
Structurally, all subtilisins are very similar with roughly 275 amino acids forming a globular protein with several alpha-helices flanking both sides of a large beta-sheet (see Figure 2
with a pairwise amino acid identity ...