Production of a Fermented Solid Containing Lipases of Rhizopus microsporus and Its Application in the Pre-Hydrolysis of a High-Fat Dairy Wastewater
Dayane Alberton1, David Alexander Mitchell1, Jesús Cordova2,3, Patrício Peralta-Zamora3 and Nadia Krieger3*
1Department of Biochemistry and Molecular Biology, Federal University of Paraná, Centro Politécnico, P.O. Box 19046, Curitiba 81531-980, Paraná, Brazil
2Department of Chemical Engineering, CUCEI, University of Guadalajara, Blvd. Marcelino García Barragán y Calz. Olímpica, 44840 Guadalajara, Jalisco, Mexico
3Department of Chemistry, Federal University of Paraná, Centro Politécnico, P.O. Box 19081, Curitiba 81531-980, Paraná, Brazil
Article history:
Received August 21, 2009
Accepted November 10, 2009
Key words:
lipolysis, enzymatic pretreatment, solid-state fermentation, solid-state cultivation, dairy wastewater, Rhizopus microsporus
Summary:
The filamentous fungus Rhizopus microsporus CPQBA 312-07 DRM was grown in solid-state cultivation and the fermented solid produced was used to hydrolyze triacylglycerols in a high-fat dairy wastewater. For the solid-state cultivation, a mixture of sunflower seed meal and sugarcane bagasse (1:3 by mass on dry basis) was selected. After 18 h of culture, the fermented product had an activity, measured titrimetrically against triolein, of 26 U per gram of dry solids. This substrate mixture does not suffer from compaction and therefore can be used in large scale solid-state cultivation bioreactors. When used to pretreat a high-fat dairy wastewater, with an oil and grease level above 1300 mg/L, the fermented solid reduced the oil and grease level to below 300 mg/L after 72 h at 35 °C. Further work is required to improve the production of lipolytic activity in the solid-state cultivation step and to find the optimum pretreatment time in the wastewater pretreatment step.
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