Growth of Pseudomonas fluorescens on a polyester–polyurethane and the purification and characterization of a polyurethanase–protease enzyme

A Pseudomonas fluorescens was found to degrade and utilize a polyester polyurethane as a sole carbon and energy source. Polyurethane utilization by P. fluorescens. followed simple Michaelis–Menten kinetics. The Ks and μmax values were 0.9 mg ml−1 and 1.61 doublings • h−1, respectively. The enzymes from P. fluorescens responsible for polyurethane degradation were found to be extracellular. Analysis of the polyurethane degrading proteins using non-denaturing polyacrylamide gel electrophoresis revealed one active protein band with an Rf value of 0.083. A polyurethane degrading enzyme was purified and displayed protease activity. This enzyme was inhibited by phenylmethylsulfonyl fluoride and had a molecular weight of 29,000 daltons.