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In this study, Candida antarctica lipase B (CALB) is immobilized onto ECR1030 resin and the obtained immobilized preparation is used for the synthesis of n-3 polyunsaturated fatty acids (PUFA)-rich triacylglycerols (TAG). The immobilization process is systematically studied. Under the optimized conditions, the immobilized preparation of ECR1030-CALB with an esterification activity of 10 058 U g−1 is obtained, which is comparable with the commercially available Novozym 435. Confocal microscopy images showed that CALB diffused from the surface to the center of carrier during immobilization. The basic properties of ECR1030-CALB is also investigated and it is found that the thermostability, acidic and alkaline stability, and organic solvent tolerance of ECR1030-CALB are comparable with Novozym 435. Interestingly, ECR1030-CALB showed significantly higher specificity toward EPA and DHA compared with Novozym 435, which made it suitable for the synthesis of n-3 PUFA-rich TAG. Overall, the prepared ECR1030-CALB with excellent esterification activity, basic properties, and catalytic performance might be a promising alternative to commercial Novozym 435. Practical Applications: A previous study found that ECR1030 resin was a robust and promising carrier for the immobilization of CALB. However, the detailed immobilization conditions, the basic properties, and catalytic performance of the immobilized preparations using ECR1030 resin as carrier are still unknown. Consequently, knowledge of the above unknown information for the immobilization of CALB using ECR1030 resin as carrier is of great importance for their further practical applications in lipid chemistry. [ABSTRACT FROM AUTHOR]

Production and immobilization of lipase SMG1 and its application in catalyzing the esterification of oleic acid with glycerol were investigated. Resin D380 was screened to immobilize enzyme among five types of macroporous resins, and Fourier transform IR analysis proved the ionic bonds between functional group (NH2) and the amino acid residues in protein molecules. The immobilized lipase SMG1, with lipase/support ratio of 75 mg/g resin and pH 7.0, was used to catalyze the esterification, and high esterification degree of 68.37% was obtained under the conditions of the immobilized lipase at a concentration of 7.5% (w/w, with respect to total reactants), a fatty acid/glycerol molar ratio of 1:7, and 40°C. The immobilized lipase retained 49.7% of its initial activity after being used for six times. Compared with the free lipase SMG1, the immobilized one was discovered to exhibit higher temperature tolerance (40°C for the immobilized lipase SMG1 and 30°C for the free one) in the esterification of fatty acid and glycerol. The new finding on the improved operation temperature of the immobilized lipase SMG1 will push the enzyme's application in the oils and fats industry. Practical applications: The immobilized lipase SMG1-catalyzed process for production of partial glycerides from glycerol and oleic acid described in this study provides several advantages over conventional methods including the absence of TAG product, the repeatable utilization of catalyst, and a high purity of DAG. Research on the immobilization of lipase SMG1, which is a novel mono- and diacylglycerol enzyme, has been firstly investigated. Compared with the free lipase, immobilized lipase SMG1 presented enhanced thermal stability in the esterification of glycerol with fatty acid. The new finding on the improved operation temperature of immobilized lipase SMG1 will push the enzyme's application in the oils and fats industry. [ABSTRACT FROM AUTHOR]

α‐Linolenic acid‐rich diacylglycerol has been demonstrated with promising health promotion functions. This study examined the production, immobilization of lipase PCL, and its application in the synthesis of diacylglycerol by esterification of α‐linolenic acid with glycerol. The resin ECR8806 was selected as an effective support for the immobilization of lipase PCL. Fourier transform infrared and Laser scanning confocal microscope analysis proved that the lipase was successfully immobilized on the resin. Compared with the free PCL, the immobilized one exhibited higher temperature tolerance. Under optimized reaction conditions, a DAG content of 54.49% were obtained. After further purified by molecular distillation, the purity of DAG was up to 99.28%. During esterification, the immobilized PCL was quite stable and retained more than 91.60% of its initial activity after 10 cycles. These new findings on the immobilized PCL will make it to be a prospective enzyme in oils and fats industry. Practical applications: Immobilized PCL, a monoacylglycerol and diacylglycerol lipase, was first employed to synthesis of a high purity α‐linolenic acid‐rich diacylglycerol. The improved biocatalytic performance and reusability of the lipase make it to be a promising catalyst in industrial application. [ABSTRACT FROM AUTHOR]

In this study, a mutant lipase of SMG1 from Malassezia globosa (SMG1-F278N) was immobilized directly from crude fermentation broth onto a novel epoxy resin (ECR8285). The obtained immobilized SMG1-F278N was characterized and its application in synthesis of partial glycerides was evaluated. The immobilization was best achieved by an initial buffer pH of 6.0, an ionic strength of 1.5 mol/L and a lipase/support ratio of 20 mg/g. Several analytical approaches such as Scanning electron microscope (SEM) and Fourier transform infrared (FT-IR) spectroscopy showed that SMG1-F278N was successfully immobilized onto ECR8285. Besides, the properties of immobilized SMG1-F278N were investigated and it was shown that immobilized SMG1-F278N improved their performance in wider ranges of pH and temperature. It was interesting that the thermostability of immobilized SMG1-F278N was improved significantly relative to the free SMG1-F278N. Moreover, the immobilized SMG1-F278N was employed to synthesis of partial glycerides [diacylglycerol (DAG), monoacylglycerol (MAG)] via esterification of oleic acids and glycerol. High yield (79%) of partial glycerides was obtained and it was observed that high substrate molar ratio of glycerol to oleic acids contributes to the conversion of oleic acids as well as the accumulation of MAG. The immobilized SMG1-F278N was quite stable and can be reused for 7 cycles without significant loss in activity (2%). The obtained results demonstrated that the immobilized SMG1-F278N is a prospective enzyme in oils and fats industry. [ABSTRACT FROM AUTHOR]

The catalytic activity of Candida antarctica lipase B (CALB) immobilized on modified cellulose nanocrystals (CNC) with different hydrophobicity was investigated using experimental and theoretical approaches. Firstly, the modified CNC were characterized by multi-spectroscopic methods, water contact angle, scanning electron microscopy and thermogravimetric analysis. Moderately hydrophobic CNC were found to be an optimal support for CALB immobilization. Secondly, model systems contained a CALB molecule and different numbers of modified CNC molecules (CALB@3CNC-C16, CALB@10CNC-C16 and CALB@15CNC-C16) were prepared for molecular dynamics (MD) simulation. Root-mean-square fluctuation values (0.61–2.61 Å) of lid region were relatively high in CALB@10CNC-C16, indicating that modified CNC with moderate hydrophobicity favored forming a lid-open conformation of CALB. Finally, the esterification of oleic acid catalyzed by the immobilized CALB showed higher conversion (54.68 %) than free CALB (12.98 %). Insights into modified CNC with tunable properties provided by this study may be a potential support for improving the catalytic performance of lipases. • The activity of CALB was tunable by hydrophobicity of cellulose nanocrystals (CNC). • Immobilized CALB had remarkably higher thermal and pH stability than free CALB. • Modified CNC with moderate hydrophobicity favored a open conformation of CALB. [ABSTRACT FROM AUTHOR]

Conjugated linoleic acid (CLA)-rich triacylglycerols (TAG) have received significant attention owing to their health promoting properties. In this study, CLA-rich TAG were successfully synthesized by an immobilized mutant lipase (MAS1-H108A)-catalyzed esterification of CLA-rich fatty acids and glycerol under vacuum. MAS1-H108A was first immobilized onto ECR1030 resin. Results showed that the lipase/support ratio of 41 mg/g was suitable for the immobilization and the thermostability of immobilized MAS1-H108A was greatly enhanced. Subsequently, the immobilized MAS1-H108A was employed for the synthesis of CLA-rich TAG and 95.21% TAG with 69.19% CLA was obtained under the optimized conditions. The TAG content (95.21%) obtained by immobilized MAS1-H108A is the reported highest value thus far, which was significantly higher than that (9.26%) obtained by Novozym 435 under the same conditions. Although the TAG content comparable to the results obtained in this study could also be obtained by Novozym 435, the used enzyme amount is approximately 5-fold of the immobilized MAS1-H108A. Additionally, the immobilized MAS1-H108A exhibited excellent recyclability during esterification retaining 95.11% of its initial activity after 10 batches. Overall, such immobilized mutant lipase with superior esterification activity and recyclability has the potential to be used in oils and fats industry. [ABSTRACT FROM AUTHOR]