A novel alkaline, thermostable, protease-free lipase from Pseudomonas sp.

An extracellular, alkali-tolerant, thermostable lipase was from a Pseudomonas sp. It had optimal activity at 65 degrees C and retained 75% of its activity at 65 degrees C for 90 min. The pH optimum was 9.6 and it retained more than 70% activity between pH 5 and 9 for 2 h. The culture broth was free of protease and, at 30 degrees C, the culture filtrate retained all the activity for at least 7 days, without any stabilizer. In shake flask culture, addition of groundnut oil (3 g l(-1)) towards the end of growth phase increased the activity from 4 U ml(-1) to 8 U ml(-1).