The alkaline peptidase from P. fluorescens CY091, which shows 48% sequence coverage in the mass spectrometric analysis, had optima between 40 and 45 °C and pH 7 and 8. In contrast, Koka and Weimer (2000) and Schokker and Van Boekel (1997) described pH optima of 5 and of 9.5–10 for peptidases from P. fluorescens RO98 and P. fluorescens 22F, respectively.