Evaluation of activity of Bacillus lipase (free and immobilized) treated with compressed propane

• Influence of temperature and pressure.
• Activity of lipase from a newly isolated Bacillus sp. ITP-001.
• Free form and immobilized by the sol–gel technique.
• Compressed propane and at different times after treatment.

This work is focused on the evaluation the lipase stability from newly isolated Bacillus sp. ITP-001 after different times treatment with propane at 45 and 60 °C and pressures of 50 and 200 bar, considering the free form of lipase and also the enzyme immobilized by the sol–gel technique. The hydrolytic activity of the free lipase remained constant up 360 min of incubation at 60 °C/200 bar (approximately 15% of constant activity gain). For the esterification reaction a gain up to 500% was observed at the initial time when the enzyme was submitted to 45 °C/200 bar. For the immobilized enzyme, a lose in the hydrolytic activity was observed after the high pressure treatment, but the esterification activity was improved up to 50% at 60 °C/200 bar. In general, these results show that enzyme activity changes significantly depending on the enzyme and the experimental conditions investigated.

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