| 초록 |
Biodiesel is a renewable and domestic resource with an environmentally friendly emission profile and is readily biodegradable. The acid-catalyzed process can not help making waste water and avoiding the complex pretreatment. In contrast, lipase catalyzed transesterification has less pretreatment steps and is able to conduct that at mild condition. In this study, fatty acid methyl ester ( FAMEs) were produced from oil by transesterification using lipase. The tested microorganisms were Candida rugosa, Candida Antarctica, Rhizopus oryzae, Pseudomonas fluorescens and, Burkholderia multivorans. Rhizopus oryzae was shows highest lipase activity compare with other microorganisms, so it was chosen for the reaction. To increase the conversion of oil, optimization of the culture conditions and enzyme concentration were carried out. The optimum medium for producing lipase (16.1U/ml) was 4% olive oil, 8% Bacto peptone, 0.1% NaNO3, 0.1% KH2PO4, 0.05% MgSO47H2O at 28 ℃, and 250 rpm. The extracellular lipase was concentrated 12 fold by ammonium sulfate precipitation and ultra filtration. Rhizopus oryzae lipase (15 U/ml) showed the highest conversion of 58% among others tested. |
