کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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70698 | 48842 | 2009 | 5 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Use of mono- and diacylglycerol lipase as immobilized fungal whole cells to convert residual partial glycerides enzymatically into fatty acid methyl esters Use of mono- and diacylglycerol lipase as immobilized fungal whole cells to convert residual partial glycerides enzymatically into fatty acid methyl esters](/preview/png/70698.png)
The accumulation of partial glycerides such as monoglyceride (MG) and diglyceride (DG) is one of the rate-limiting steps in plant oil methanolysis catalyzed by Rhizopus oryzae producing triacylglycerol lipase. To convert partial glycerides efficiently into their corresponding methyl esters (MEs), we attempted to use a mono- and diacylglycerol lipase (mdlB) derived from Aspergillus oryzae. By considering cost efficiency, R. oryzae and recombinant mdlB-producing A. oryzae were immobilized independently within polyurethane foam biomass support particles and directly utilized as a whole-cell biocatalyst. The mdlB-producing A. oryzae effectively exhibited substrate specificity toward MG and DG and was then used for the methanolysis of intermediate products (approximately 82% ME), which were produced using R. oryzae. In the presence of 5% water, the use of mdlB-producing A. oryzae resulted in less than 0.1% of MG and DG, whereas a considerable amount of triglyceride was present in the final reaction mixture. On the basis of these results, we developed a packed-bed reactor (PBR) system, which consists of the first column with R. oryzae and the second column containing both R. oryzae and mdlB-producing A. oryzae. Ten repeated-batch methanolysis cycles in the PBR maintained a high ME content of over 90% with MG and DG at 0.08–0.69 and 0.22–1.45%, respectively, indicating that the PBR system can be used for long-term repeated-batch methanolysis with partial glycerides at low levels. The proposed method is therefore effective for improving enzymatic biodiesel production.
Journal: Journal of Molecular Catalysis B: Enzymatic - Volume 58, Issues 1–4, June 2009, Pages 93–97