Lipase-producing fungi for potential wastewater treatment and bioenergy production

Abstract

The use of fungal biomass as a lipase biocatalyst represents an attractive approach for the treatments of oil wastewater as well as for the production of biodiesel from oil and residual grease, due to its greater  stability, possibility of reuse, and lower cost. In this work, 20 filamentous fungi were isolated from the grease trap scum of a restaurant at the Federal University of Espírito Santo, Brazil. The fungi included those belonging to the genera Aspergillus, Beauveria, Botrytis, Cladosporium, Colletotrichum, Fusarium, Geotrichum, Penicillium, Rhizomucor, and Verticillium. Fungal lipase activity and biomass production were quantified. Lipase activity ranged from 0.13 U mg^-1 protein of Rhizomucor sp. ECGF18 to 18.06 U mg^-1 protein of Penicillium sp. ECGF02, and the biomass production ranged from 7.61 mg mL^-1 for  Cladosporium sp. ECGF19 to 12.68 mg mL^-1 for Rhizomucor sp. ECGF18. In the sequence, Penicillium sp. ECGF02 and Rhizomucor sp. ECGF18, were previously select and, further evaluated in solid-state fermentation. Results confirmed the high extracellular lipase-activity of Penicillium sp.ECG02 and the high intracellular lipase activity of Rhizomucor sp. ECG18. Rhizomucor sp. ECG18 showed potential for use in future research, in the form of whole-cell lipases, wastewater treatment, and as a biocatalyst in the production of biodiesel from oil residues.

Key words: Lipase-producing fungi, wastewater treatment, bioenergy.