Use of Coomassie blue-polyurethane interaction inscreening of polyurethanase proteins andpolyurethanolytic bacteria

The interaction of the dye Coomassie blue with intact polyurethane provides the basisfor a rapid and sensitive assay system for bacterial strains posing polyurethanase activity. Thepotential advantage of this system in enumerating and characterizing polyurethanolytic bacteriaderives largely from the intense color of the dye-substrate complex, which allows the use of verylow substrate concentrations and a corresponding decrease in the time required to detect lowerlevels of enzyme activity. The method entails incubation of agar plates containing thepolyurethane substrate, followed by immersion in 0.1% Coomassie blue then destaining with 10%acetic acid-40% methanol. Resulting agar plates contain transparent bands corresponding toenzymatic activity against a blue background.