40 research outputs found

    Synthesis of conjugated linoleic acid-rich triacylglycerols by immobilized mutant lipase with excellent capability and recyclability

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    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

    Purification and Structural Characterization of the Auxiliary Activity 9 Native Lytic Polysaccharide Monooxygenase from Thermoascus aurantiacus and Identification of Its C1- and C4-Oxidized Reaction Products

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    Auxiliary activity 9 (AA9) lytic polysaccharide monooxygenases (LPMOs) are copperdependentoxidoreductases that use O2 or H2O2 to perform oxidative cleavage of cellulose in thepresence of an electron donor. Combined with cellulases, they can assist in a more efficient cleavageof cellulose. AA9 LPMOs have therefore attracted considerable attention in recent years for use inbiotechnological applications. Here, a native AA9 LPMO (nTaAA9A) from the thermophilic fungusThermoascus aurantiacus was purified and characterized. The enzyme was shown to be active and ableto cleave cellulose and xylan to produce C1- and C4-oxidized products. It was also found to retainabout 84.3, 63.7, and 35.3% of its activity after incubation for 30 min at 60, 70, and 80 C, respectively,using quantitative activity determination. The structure was determined to 1.36 Å resolution andcompared with that of the recombinant enzyme expressed in Aspergillus oryzae. Structural differencesin the glycosylated Asn138 and in solvent-exposed loops were identified.</p

    Thermophoretic deposition of particles in fully developed mixed convection flow in a parallel-plate vertical channel: the full analytical solution

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    In a recent paper (Grosan et al. in Heat Mass Transf 45:503-509, 2009) a mostly numerical approach to the title problem has been reported. In the present paper the full analytical solution is given. Several new features emerging from this approach are discussed in detai

    Design and characterization of the readout ASIC for the BESIII CGEM detector

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    TIGER (Turin Integrated Gem Electronics for Readout) is a mixed-mode ASIC for the readout of signals from CGEM (Cylindrical Gas Electron Multiplier) detector in the upgraded inner tracker of the BESIII experiment, carried out at BEPCII in Beijing. The ASIC includes 64 channels, each of which features a dual-branch architecture optimized for timing and energy measurement. The input signal time-of-arrival and charge measurement is provided by low-power TDCs, based on analogue interpolation techniques, and Wilkinson ADCs, with a fully-digital output. The silicon results of TIGER first prototype are presented showing its full functionality.Peer Reviewe

    Purification and Structural Characterization of the Auxiliary Activity 9 Native Lytic Polysaccharide Monooxygenase from Thermoascus aurantiacus and Identification of Its C1- and C4-Oxidized Reaction Products

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    Auxiliary activity 9 (AA9) lytic polysaccharide monooxygenases (LPMOs) are copper-dependent oxidoreductases that use O2_2 or H2_2O2_2 to perform oxidative cleavage of cellulose in the presence of an electron donor. Combined with cellulases, they can assist in a more efficient cleavage of cellulose. AA9 LPMOs have therefore attracted considerable attention in recent years for use in biotechnological applications. Here, a native AA9 LPMO (nTaAA9A) from the thermophilic fungus Thermoascus aurantiacus was purified and characterized. The enzyme was shown to be active and able to cleave cellulose and xylan to produce C1- and C4-oxidized products. It was also found to retain about 84.3, 63.7, and 35.3% of its activity after incubation for 30 min at 60, 70, and 80 °C, respectively, using quantitative activity determination. The structure was determined to 1.36 Å resolution and compared with that of the recombinant enzyme expressed in Aspergillus oryzae. Structural differences in the glycosylated Asn138 and in solvent-exposed loops were identified

    Data exchange requirement analysis for value for money assessment in public-private partnerships

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    Value for money (VfM) as the lifecycle assessment approach in publicprivate partnerships (PPP) essentially covers the overall project performance in both qualitative and quantitative ways. However, the performance measurement in VfM is still lacking supporting data in the project lifecycle. Based on the performance structure of the VfM quantitative assessment, this article developed a data extraction scheme integrated with building information modelling (BIM). The domain of modules mainly covers buildings, civil engineering and highways according to a related measurement standard. By extracting the data types from the original BIM model, the filtered information can facilitate a quantitative assessment by obtaining the required data automatically

    Purification and Structural Characterization of the Auxiliary Activity 9 Native Lytic Polysaccharide Monooxygenase from <i>Thermoascus aurantiacus</i> and Identification of Its C1- and C4-Oxidized Reaction Products

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    Auxiliary activity 9 (AA9) lytic polysaccharide monooxygenases (LPMOs) are copper-dependent oxidoreductases that use O2 or H2O2 to perform oxidative cleavage of cellulose in the presence of an electron donor. Combined with cellulases, they can assist in a more efficient cleavage of cellulose. AA9 LPMOs have therefore attracted considerable attention in recent years for use in biotechnological applications. Here, a native AA9 LPMO (nTaAA9A) from the thermophilic fungus Thermoascus aurantiacus was purified and characterized. The enzyme was shown to be active and able to cleave cellulose and xylan to produce C1- and C4-oxidized products. It was also found to retain about 84.3, 63.7, and 35.3% of its activity after incubation for 30 min at 60, 70, and 80 °C, respectively, using quantitative activity determination. The structure was determined to 1.36 Å resolution and compared with that of the recombinant enzyme expressed in Aspergillus oryzae. Structural differences in the glycosylated Asn138 and in solvent-exposed loops were identified

    Data_Sheet_1_Analysis of lytic polysaccharide monooxygenase activity in thermophilic fungi by high-performance liquid chromatography–refractive index detector.docx

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    IntroductionMost current methods for analysing the activity of LPMO are based on the quantification of H2O2, a side product of LPMO; however, these methods cannot assay the LPMO activity of thermophilic fungi because of the low thermostability of H2O2. Therefore, we present a high-performance liquid chromatography–refractive index detector (HPLC-RID) method to assay the LPMO activity of the thermophilic fungus Thermoascus aurantiacus.ResultsAccording to the established method, the specific activities of nTaAA9A C1 and C4 oxidation were successfully analysed and were 0.646 and 0.574 U/mg, respectively. By using these methods, we analyzed the C1 and C4 oxidation activities of the recombinant TaAA9A (rTaAA9A) and mutated rTaAA9A (Y24A, F43A, and Y212A) expressed in Pichia pastoris. The specific activities of rTaAA9A C1 and C4 oxidation were 0.155 and 0.153 U/mg, respectively. The specific activities of Y24A, F43A, and Y212A C1 and C4 oxidation were 0.128 and 0.125 U/mg, 0.194 and 0.192 U/mg, and 0.097 and 0.146 U/mg, respectively.DiscussionIn conclusion, the method can assay the LPMO activity of thermophilic fungi and directly target C1 and C4 oxidation, which provides an effective activity assay method for LPMOs of thermophilic fungi.</p
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