Production and partial characterization of extracellular lipase from Trichoderma harzianum by solid-state fermentation

The growing interest in lipase production is related to the potential biotechnological applications that these enzymes present. Current studies on lipase production by solid state fermentation involve the use of agro-industrial residues, aiming at increasing the economic attractiveness. Based on these aspects, the objective of this work was to investigate lipase production by a local strain Trichoderma harzianum in solid-state fermentation (SSF), using wheat bran as a solid substrate, and compare this lipase production with submerged fermentation (SmF) using a mineral culture medium. The maximum lipase activity, 1.82 U·mL-1 ± 0.01 U·mL-1, was obtained during submerged fermentation in a medium containing 2% sucrose and 2% olive oil. However, 71.3 U·g-1 ± 1.48 U·g-1 of dry solid substrate equivalent to 14.3 U·mL-1 of lipase activity was reached using a solid-state fermentation process with a medium containing 0.75 % ammonium sulphate and 0.34 % urea, 2 % olive oil and wheat bran as a solid substrate. The pH and temperature optima for lipase were 8.03 and 40 °C, respectively. The Michaelis constant (KM = 6.6 mmol·L-1) was obtained from two different plots, i.e. Lineweaver-Burk and Hanes-Woolf. Vmax of the enzyme reaction was found to be 7.5 U·mL-1