Immobilization in the presence of Triton X-100: modifications in activity and thermostability of Geobacillus thermoleovorans CCR11 lipase

A partially purified lipase produced by the thermophile Geobacillus thermoleovorans CCR11 was immobilized by adsorption on porous polypropylene (Accurel EP-100) in the presence and absence of 0.1% Triton X-100. Lipase production was induced in a 2.5% high oleic safflower oil medium and the enzyme was partially purified by diafiltration (co. 500,000 Da). Immobilization conditions were established at 25 °C, pH 6, and a protein concentration of 0.9 mg/mL in the presence and absence of 0.1% Triton X-100. Immobilization increased enzyme thermostability but there was no change in neither the optimum pH nor in pH resistance irrelevant to the presence of the detergent during immobilization. Immobilization with or without Triton X-100 allowed the reuse of the lipase preparation for 11 and 8 cycles, respectively. There was a significant difference between residual activity of immobilized and soluble enzyme after 36 days of storage at 4 °C ( P