Lipase immobilization for catalytic applications obtained using fumed silica deposited with MAPLE technique

Bloisi, F.; Califano, Valeria; Perretta, Gemma; Nasti, Libera; Aronne, Antonio; Girolamo, Rocco Di; Auriemma, Finizia; Rosa, Claudio De; Vicari, L.

doi:10.1016/j.apsusc.2015.12.131

Cited by 12 publications

(9 citation statements)

References 49 publications

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“…A smaller apparent K M indicated that the immobilized enzyme had higher affinity for its substrate or that there was an enhanced substrate concentration near the active sites caused by the interactions between the substrate and the matrix. Actually, WSNs contain a great number of surface silanol Si-OH, as testified by the presence of a band 970 cm −1 in the FT-IR spectra of Figure 1 (stretching vibration of Si-OH) [56]. Surface silanols can interact with cellobiose via hydrogen bonding, causing an increased local concentration [57].…”

Section: Resultsmentioning

confidence: 99%

Covalent Immobilization of β-Glucosidase into Mesoporous Silica Nanoparticles from Anhydrous Acetone Enhances Its Catalytic Performance

et al. 2020

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An immobilization protocol of a model enzyme into silica nanoparticles was applied. This protocol exploited the use of the bifunctional molecule triethoxysilylpropylisocyanate (TEPI) for covalent binding through a linker of suitable length. The enzyme β-glucosidase (BG) was anchored onto wrinkled silica nanoparticles (WSNs). BG represents a bottleneck in the conversion of lignocellulosic biomass into biofuels through cellulose hydrolysis and fermentation. The key aspect of the procedure was the use of an organic solvent (anhydrous acetone) in which the enzyme was not soluble. This aimed to restrict its conformational changes and thus preserve its native structure. This approach led to a biocatalyst with improved thermal stability, characterized by high immobilization efficiency and yield. It was found that the apparent KM value was about half of that of the free enzyme. The Vmax was about the same than that of the free enzyme. The biocatalyst showed a high operational stability, losing only 30% of its activity after seven reuses.

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Section: Resultsmentioning

confidence: 99%

Covalent Immobilization of β-Glucosidase into Mesoporous Silica Nanoparticles from Anhydrous Acetone Enhances Its Catalytic Performance

et al. 2020

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“…In both spectra, there are bands related to Si−O−Si vibrational modes at 500 (δSi−O−Si), 800 (νsym Si−O−Si), and 1090 cm −1 (transversal optic (TO) ν asym Si−O−Si), with a shoulder at 1200 cm −1 (longitudinal optic (LO) νasym Si−O−Si). The position of these bands is the same for the two samples and is indicative of a dense silica network [30]. The bands at 560 (δSi−OH) and 960 cm −1 (νSi−OH) indicate the presence of surface Si−OH groups.…”

Section: Ftir and Tg Analysismentioning

confidence: 79%

“…The amount of BG was 0.15 mg/mL for all samples. The reaction kinetics was monitored at different times (10,30,60,120,240, and 1440 min) by making subsequent samplings. The reaction was stopped by thermal inactivation at 100 • C for 10 min.…”

Section: Batch Reactor Setupmentioning

confidence: 99%

Immobilization of β-Glucosidase over Structured Cordierite Monoliths Washcoated with Wrinkled Silica Nanoparticles

et al. 2020

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The enzymatic conversion of biomass-derived compounds represents a key step in the biorefinery flowsheet, allowing low-temperature high-efficiency reactions. β-Glucosidases are able to hydrolyze cellobiose into glucose. Wrinkled silica nanoparticles (WSNs) were demonstrated to be a good support for the immobilization of β-glucosidases, showing better performance than free enzymes in batch reaction; on the other hand, immobilized enzyme microreactors (IEMs) are receiving significant attention, because small quantities of reagents can be used, and favorable heat and mass transfer can be achieved with respect to conventional batch systems. In this work, we prepared, characterized, and tested structured enzymatic reactor compounds by a honeycomb monolith, a WSN washcoat, and β-glucosidases as the active phase. Powder and structured materials were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), N2 physisorption, thermogravimetric analysis (TGA), and Fourier-transform infrared spectroscopy (FT-IR). Structured catalysts were tested under both batch and continuous flow reaction conditions and compared to powder catalysts (batch reaction). The WSN washcoat was attached well onto the monolith walls, as suggested by the negligible weight loss after ultrasound treatment; the WSNs preserved their shape, porosity, and individual nature when deposited onto the monolith walls. The immobilized enzyme microreactors proved to be very efficient in hydrolysis of cellobiose to glucose, showing a complete conversion under continuous flow reaction at a batch-equivalent contact time equal to 120 min vs. 24 h obtained in the batch experiments. The apparent KM value showed a 20-fold decrease with respect to the batch process, due to the absence of external diffusive transport limitations.

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“…Curve fitting of the amide A band for the three MAPLE-deposited lipases was performed giving two Gaussian components for all samples ( Table 5 ). In this region the contribute related to the O-H stretching of water can be considered to have a little influence in the overall absorption, since it was demonstrated that the MAPLE process is effective in removing water from the deposited samples [ 47 ]. The amide A band can be considered as due to the overlapping of two components: one at about 3300 cm −1 can be related to hydrogen-bonded N-H stretching vibrations; the second at about 3420 cm −1 can be related to vibrations of free N-H groups of the unfolded peptide forms [ 41 ].…”

Section: Resultsmentioning

confidence: 99%

Frozen Microemulsions for MAPLE Immobilization of Lipase

et al. 2017

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Candida rugosa lipase (CRL) was deposited by matrix assisted pulsed laser evaporation (MAPLE) in order to immobilize the enzyme with a preserved native conformation, which ensures its catalytic functionality. For this purpose, the composition of the MAPLE target was optimized by adding the oil phase pentane to a water solution of the amino acid 3-(3,4-dihydroxyphenyl)-2-methyl-l-alanine (m-DOPA), giving a target formed by a frozen water-lipase-pentane microemulsion. Fourier transform infrared (FTIR) spectroscopy and atomic force microscopy (AFM) were used to investigate the structure of MAPLE deposited lipase films. FTIR deconvolution of amide I band indicated a reduction of unfolding and aggregation, i.e., a better preserved lipase secondary structure in the sample deposited from the frozen microemulsion target. AFM images highlighted the absence of big aggregates on the surface of the sample. The functionality of the immobilized enzyme to promote transesterification was determined by thin layer chromatography, resulting in a modified specificity.

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Lipase immobilization for catalytic applications obtained using fumed silica deposited with MAPLE technique

Cited by 12 publications

References 49 publications

Covalent Immobilization of β-Glucosidase into Mesoporous Silica Nanoparticles from Anhydrous Acetone Enhances Its Catalytic Performance

Covalent Immobilization of β-Glucosidase into Mesoporous Silica Nanoparticles from Anhydrous Acetone Enhances Its Catalytic Performance

Immobilization of β-Glucosidase over Structured Cordierite Monoliths Washcoated with Wrinkled Silica Nanoparticles

Frozen Microemulsions for MAPLE Immobilization of Lipase

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