• Applied Chemistry for Engineering
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• v.16 no.6
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• pp.731-736
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• 2005

In this paper, immobilization of lipase (Rhizomucor miehei, Rhm) onto ion-exchange resin pretreated with oleic acid and its application were studied. Immobilization efficiency was reached to 82% when weakly basic anion exchange resin, Duolite A-568, was used. Immobilized Rhm was stable in water, chloroform and hexane, however, unstable in alcoholic solvents. When immobilized Rhm was applied to the esterification reaction of glycerol and fatty acid, content of DG in the product mixture was ca. 80 mol% and 1,3-DG in total DG reached to 98%.

• Journal of Microbiology and Biotechnology
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• v.27 no.2
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• pp.277-288
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• 2017

Rhizomucor miehei NRRL 5282 and Rhizopus oryzae NRRL 1526 can produce lipases with high synthetic activities in wheat bran-based solid-state culture. In this study, the purification and biochemical characterization of the lipolytic activities of these lipases are presented. SDS-PAGE indicated a molecular mass of about 55 and 35 kDa for the purified R. miehei and Rh. oryzae enzymes, respectively. p-Nitrophenyl palmitate (pNPP) hydrolysis was maximal at $40^{\circ}C$ and pH 7.0 for the R. miehei lipase, and at $30^{\circ}C$ and pH 5.2 for the Rh. oryzae enzyme. The enzymes showed almost equal affinity to pNPP, but the $V_{max}$ of the Rh. oryzae lipase was about 1.13 times higher than that determined for R. miehei using the same substrate. For both enzymes, a dramatic loss of activity was observed in the presence of 5 mM $Hg^{2+}$, $Zn^{2+}$, or $Mn^{2+}$, 10 mM N-bromosuccinimide or sodium dodecyl sulfate, and 5-10% (v/v) of hexanol or butanol. At the same time, they proved to be extraordinarily stable in the presence of n-hexane, cyclohexane, n-heptane, and isooctane. Moreover, isopentanol up to 10% (v/v) and propionic acid in 1 mM concentrations increased the pNPP hydrolyzing activity of R. miehei lipase. Both enzymes had 1,3-regioselectivity, and efficiently hydrolyzed p-nitrophenyl (pNP) esters with C8-C16 acids, exhibiting maximum activity towards pNP-caprylate (R. miehei) and pNP-dodecanoate (Rh. oryzae). The purified lipases are promising candidates for various biotechnological applications.

• Fisheries and Aquatic Sciences
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• v.12 no.1
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• pp.16-23
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• 2009

Lipids were extracted from marine rotifer, Brachionus rotundiformis in order to examine the functionality of lipid enzymatic modification. The fatty acids, palmitic, linoleic, oleic and stearic acids were the dominant forms accounting for approximately 35.8%, 21.5%, 15.9% and 7.7% of the total lipid content, respectively. Lipid fractions were categorized as neutral lipids (38.5%), glycolipids (45.9%) and phospholipids (17.6%), and after extraction from the rotifer were isolated by thin-layer chromatography (TLC) as free fatty acids (FFA), monoacylglycerol (MAG), diacylglycerol (DAG) and triacylglycerol (TAG). The production of polyunsaturated fatty acid (PUFA) concentrate from rotifer lipids was studied using lipase-catalyzed hydrolysis. In addition, rotifer lipids were modified by hydrolysis using lipases such as porcine pancreas, Candida rugosa and Rhizomucor miehei. The lipase from Rhizomucor miehei was effective in extracting linoleic acid (C 18:2), while the lipase from Candida rugosa was effective in palmitic acid (C16:0) extraction.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.7
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• pp.1052-1058
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• 2005

Structured lipid (SL) was synthesized by enzymatic interesterification with algae oil containing docosahexaenoic acid (DHA) and soybean oil in the stirred-batch type reactor. The reaction was performed for 15hr at $65^{\circ}C$ with 300 rpm catalyzed by sn-1,3 specific Lipozyme RM 1M lipase from Rhizomucor miehei ($11\%$ by weight of total substrates) in the absent organic solvent. SL contained $87.1\;area\%$ triacylglycerol (TAG), $12.1\;area\%$ diacylglycerol (DAG), $0.6\;area\%$ monoacylglycerol (MAG), and $0.2\;area\%$ free fatty acid (FFA). Major fatty acid profiles of SL were DHA $(15.7\;mol\%)$, linoleic $(31.1\;mol\%)$, palmitic $(20.2\;mol\%)$, oleic $(13.5\;mol\%)$ and eicosapentaenoic acid $(EPA,\;6.6 mol\%)$. SL contained the newly synthesized several peaks. Iodine and saponification of SL were 206.7 and 183.8. SL color showed darker and redder than soybean oil, and appeared the most yellowish color among SL, soybean, and algae oil.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.6
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• pp.1000-1005
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• 2004

Structured lipids (SLs) were synthesized by acidolysis of crude oils (corn and peanut oil) and conjugated linoleic acid (CLA) with a molar ratio of 1:3 (extracted oil:CLA) in a shaking water bath. The reaction was performed for various reaction time (1, 2, 3, 6 and 24 hr) at 55$^{\circ}C$ with 175 rpm catalyzed by sn -1,3 specific IM 60 lipase from Rhizomucor miehei. The content of the incorporated CLA increased with the prolonged reaction time, showing 7.5∼9.3 ㏖% in the synthesized SL triacylglycerol molecules from the extracted corn and peanut oil. However, total tocopherol content in SLs decreased up to about 20% compared to the content in extracted oils. Among the CLA isomers, 6.3∼7.5 ㏖% of cis 9,trans 11- and trans 10,cis 12-CLA known as physiologically active compounds are contained in corn and peanut SLs.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.8
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• pp.1200-1205
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• 2003

Structured lipids (SL) were synthesized by transesterification of corn oil and conjugated linoleic acid (CLA) in the continuous type reactor using sn-1,3 specific Rhizomucor miehei lipase. The parameters of reaction were observed in terms of flow rate, temperature, and substrate molar ratios. The highest incorporation of CLA was obtained with 1 mL/min flow rate, 55$^{\circ}C$ and 1 : 3 (corn oil/CLA) molar ratio, showing 10.26 ㏖%. When different reaction temperatures and substrate ratios were studied, the highest incorporation was obtained at $65^{\circ}C$ (17.33 ㏖%) and 1 : 5 (corn oil/CLA) ratio (17.50 ㏖%), respectively. After pancreatic lipase analysis, most of all CLA were found at sn-1,3 position. The iodine values of obtained SLs ranged from 110 to 120. From the neutral lipid analysis by normal-phase HPLC, produced SLs composed of 99.35 ∼ 99.89% triacylglycerols, 0.11 ∼ 0.51% 1,2- and 1,3-diacylglycerols, and 0.06 ∼ 0.22% monoacylglycerols.

• Bulletin of Food Technology
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• v.7 no.2
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• pp.64-73
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• 1994

Using 20 lipases from various microbial origins medium chain glycerides, namely, mono-, di-, and tri-carproyl glycerols from glycerol and acid were synthesized in isooctane. Enzyme reaction was performed at 0.35 M of capric acid, 0.025M of glycerol and the same mass of silica gel to remove water in 5ml of isooctane with 30mg of lyophilized lipase. Among 20 lipases, eleven lipases showed good synthetic activities, especially lipase from Pseudomonas aeruginosa (Lipase PS), Rhizomucor miehei origined lipase and Chromobacterium viscosum lipase (Lipase CV) showed good activities for production of tricaproylglycerol, while Lipase OF-360 (origined from Candida rugosa) and Lipase D (Rhizopus delemar) were good for production of dicaprolyglycerol. The lipases, especially Lipase PS, have high thermal stability at $ 60^{circ}C$, and optimum pH of lyophilization for dehydrating the lipase was pH 6.5.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.164.2-165
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• 2003

Structured lipids (SLs) are defined as triacylglycerols to change the fatty acid composition in the glycerol backbone and lipases are known as a powerful tool for the syntheses of SLs. Structured lipid from corn oil, capric acid, and conjugated linoleic acid (CLA) by transesterification reaction and using several amounts of immobilized lipase RM IM (from Rhizomucor miehei) was studied, and 4% of lipase amount was selected for further study as the optimal amount. Comparison the chemical properties (free fatty acid value, iodine value, saponification value, tocopherols, and color analysis), solidification behavior, and volatile fractions (from headspace SPME GC-MS) between com oil and SL com oil was obtained.

• Korean Journal of Food Science and Technology
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• v.41 no.3
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• pp.231-237
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• 2009

Trans free margarine stock (TFMS) was produced by lipase-catalyzed synthesis of fully hydrogenated soybean oil (FHSBO), avocado oil (AO) and palm oil (PO). A blend of FHSBO, AO, and PO with a 1:5:4 (30:150:120 g, respectively) ratio was interesterified with lipozyme RM IM(from Rhizomucor miehei) in a 1 L-batch type reactor at 65 for 12 hr, and the physicochemical and melting properties of TFMS were compared with commercial margarine. The solid fat content (%) of the TFMS was analyzed at 25, 30, and $35^{\circ}C$, respectively, while its melting point was $37.8^{\circ}C$. The trans fatty acid content of the TFMS was below 0.1%. It also had acid, saponification, and iodine values of 0.4, 173.9, and 58.6, respectively. In HPLC chromatograms of the TFMS, newly synthesized peaks of triacylglycerol molecules were observed by using reverse-phase HPLC with evaporative light-scattering detection. Normal-phase HPLC with UV detection was used to quantify tocopherols in the TFMS, indicating that its ${\alpha}-$, ${\gamma}-$ and ${\delta}$-tocopherol contents were 5.7, 2.1, and 1.7 mg/100 g, respectively.

• Korean Journal of Food Science and Technology
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• v.37 no.4
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• pp.584-589
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• 2005

Structured triacylglycerol (SL-TAG) was synthesized by enzymatic interesterification with algae oil and soybean oil in solvent-free system. Structured di- and monoacylglycerol (SL-DAG/MAG) were produced by glycerolysis with SL-TAG and glycerol catalyzed by lipase. Reactions were performed by sn-1.3 specific Lipozyme RM IM lipase from Rhizomucor miehei (interesterification, 11%; glycerolysis 5% by weight of total substrates) in solvent-free system using stirred-batch type reactor. SL-DAG/MAG contained TAG (42,3 area%), 1,3-DAG (19.2 area%), 1,2-DAG (22.2 area%), MAG (16.0 area%), and free fatty acid (0.2 area%). Iodine and saponification values of SL-DAG/MAG were 208.8 and 179.6, respectively. SL-DAG/MAG appeared yellowish in color.