The effect of ultrasonic pre-irradiation on the stability of Pseudomonas fluorescens lipase in various solvents. pH tuned Pseudomonas fluorescens lipase (1 mg) was suspended in different solvents (100 μl each) and ultrasonicated at 110W periodically. In this study, we carried out ultrasonication for 5 minutes, followed by a break of 10 minutes between each cycle. This ensured that the temperature of the sample could be maintained at 40 ± 1°C throughout. The value on the x-axis denotes the total time during which the ultrasonicator was 'on'. Samples were extracted at various intervals (i.e. 1, 2, 3, and 4 h) and an esterase assay was performed out using pNPP as a substrate. The experiments were carried out in triplicate. The error bar reflects the reproducibility for each data point.