Effect of Nitrogen and Carbon Sources on Lipase Production by Penicillium aurantiogriseum
Valéria M. G. Lima1,2, Nadia Krieger1*, Maria Inez M. Sarquis3, David A. Mitchell4, Luiz P. Ramos1 and José D. Fontana2
1Applied Chemistry Research Centre (CEPESQ), Chemistry Department, Federal University of Parana (UFPR), PO Box 19081, Centro Politécnico, Jardim das Américas, Curitiba 81531-990, Parana, Brazil
2 Biomass Chemo/Biotechnology Laboratory (LQBB), Biochemistry and Molecular Biology Department, UFPR, Curitiba, Parana, Brazil
3FIOCRUZ – Fungal Culture Collection, IOC, Av. Brasil, 4365, Manguinhos, CEP 21045-900, Rio de Janeiro, Brasil
4Solid State Fermentation Laboratory, Biochemistry and Molecular Biology Department, UFPR, Curitiba, Parana, Brazil
Article history:
Received: December 17, 2002
Accepted: April 24, 2003
Key words:
lipases, Penicillium aurantiogriseum, media optimization, lipolytic activity, inorganic nitrogen sources
Summary:
A wild fungal strain isolated from soybean oil and identified as Penicillium aurantiogriseum initially presented a volumetric lipase activity of 0.4 U/mL in submerged culture in a medium containing 0.5 % yeast extract and 1 % olive oil. Studies were undertaken to improve lipase production. The effect of nitrogen source was studied by adding casein peptone, meat peptone, yeast extract or ammonium sulfate to a medium containing potassium nitrate and other mineral salts. The best yield, of 13 U/mL after 72 h, was obtained with the medium supplemented with ammonium sulfate. With the ammonium sulfate concentration increased to double the C/N ratio from 2.5 to 5, a lipolytic activity of 18 U/mL was obtained. Olive, corn, soy and sunflower oils were tested as carbon sources in this medium, with olive oil at 1 % giving a lipolytic activity of 25 U/mL after 48 h, the highest yield obtained in this study. Enzyme production was best at 29 °C, within a range tested from 26 to 32 °C. These results are promising because this strain produces lipase in an inexpensive inorganic medium and we succeeded in increasing the lipolytic activity 62-fold over the initial values obtained with the non-optimized medium.
*Corresponding author: nadiak@química.ufpr.br