INACTIVATION OF HEAT-RESISTANT LIPASE AND PROTEASE FROM PSEUDOMONAS-FLUORESCENS BY MANOTHERMOSONICATION

The resistance of extracellular lipase and protease from Pseudomonas f luorescens to heat treatment and manothermosonication, a simultaneous application of heat and ultrasound under moderate pressure, were compa red within a temperature range of 110 to 140 degrees C. Manothermosoni cation inactivates both enzymes more efficiently than does heat treatm ent. Because temperature dependence of enzyme inactivation is differen t for manothermosonication and simple heat treatment, manothermosonica tion efficiency diminishes as temperature increases, but this loss of efficiency during UHT can be partially overcome by elevating hydrostat ic pressure. Manothermosonication at 650 kPa and 140 degrees C reduces protease activity to 6% and lipase activity to 7% of the residual act ivity reached after identical treatment times by simple heating at 140 degrees C. At 110 degrees C, manothermosonication reduces protease ac tivity to 10(-10) and lipase activity to 0.5% of the residual activity after simple heat treatment at the identical temperatures and times.