Purification and Characterization of an Extracellular Protease Produced by Pseudomonas fluorescens M3/6

¹ Purdue University, West Lafayette, IN 47907

Pseudomonas fluorescens strain M3/6 was inoculated into reconstituted NDM and incubated at 7°C for 46 d. A significant amount of extracellular protease was produced, mainly during the latter part of the culture's life cycle. The protease was purified using ammonium sulfate fractionation, ion-exchange chromatography, and gel filtration. The isolated protease had activity on azocasein, -, ß-, and -caseins and a plasmin substrate but did not have plasminogen activator activity. The protease had a molecular weight of 45 kDa, an isoelectric point of pH 8.25, a broad temperature and pH range for activity, and was less heat stable in the isolated form than in the cell-free extract.

Key Words: Pseudomonas fluorescens • protease • enzyme

Submitted on November 8, 1990
Accepted on March 11, 1991

This article has been cited by other articles:

				B. Ismail, L. H. Choi, L. M. Were, and S. S. Nielsen Activity and nature of plasminogen activators associated with the casein micelle. J Dairy Sci, September 1, 2006; 89(9): 3285 - 3295. [Abstract] [Full Text] [PDF]

				K. A. Frohbieter, B. Ismail, S. S. Nielsen, and K. D. Hayes Effects of Pseudomonas fluorescens M3/6 Bacterial Protease on Plasmin System and Plasminogen Activation J Dairy Sci, October 1, 2005; 88(10): 3392 - 3401. [Abstract] [Full Text] [PDF]