Thermal resistance of partially purified proteinase of Pseudomonas fluorescens P‐26

Abstract

Heat resistance of the Pseudomonas fluorescens P-26 proteinase in terms of D-value was studied in whole milk, skim milk, whey and 0.05 mol l-1 phosphate buffer at 72.5, 130, 135, 140, 145 and 150 degrees C subsequent to its partial purification through (NH4)2 SO4 precipitation (45-65% saturation) and solvent fractionation with 1.0 to 2.0 volumes of isopropanol. The D-value was maximum for the proteinase at all temperatures when determined in whole milk (D150 = 0.088).

Proteolytic activity among psychrotrophic bacteria isolated from refrigerated raw milk

“…None of the crude enzymes tested showed total loss of activity, but a significant decrease was observed for Aeromonas sp. The elevated heat resistance to conventional treatments used in milk processing resembles the proteolytic activities of P. fluorescens P‐26 (Uplacksh et al. 1994) and K. oxytoca (Tondo et al.…”

Thermodynamics and Kinetics of Heat Inactivation of a Novel Keratinase from Chryseobacterium sp. Strain kr6

“…The purity of the enzyme is reported to have a strong effect on the inactivation of pseudomonal proteases [31]. The addition of sodium caseinate to an extracellular proteinase from P. fluorescens caused an increase in inactivation rate, probably caused by aggregation of the enzyme molecules with caseinate [22].…”