scholarly journals 3D Chitin Scaffolds from the Marine Demosponge Aplysina archeri as a Support for Laccase Immobilization and Its Use in the Removal of Pharmaceuticals

Biomolecules ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 646 ◽  
Author(s):  
Jakub Zdarta ◽  
Tomasz Machałowski ◽  
Oliwia Degórska ◽  
Karolina Bachosz ◽  
Andriy Fursov ◽  
...  
Keyword(s):  
Storage Stability ◽  
Packed Bed ◽  
Packed Bed Reactor ◽  
Optimum Process ◽  
Process Conditions ◽  
Total Removal ◽  
Laccase Immobilization ◽  
Continuous Use ◽  
First Time ◽  
Thermal Stability Of

For the first time, 3D chitin scaffolds from the marine demosponge Aplysina archeri were used for adsorption and immobilization of laccase from Trametes versicolor. The resulting chitin–enzyme biocatalytic systems were applied in the removal of tetracycline. Effective enzyme immobilization was confirmed by scanning electron microscopy. Immobilization yield and kinetic parameters were investigated in detail, in addition to the activity of the enzyme after immobilization. The designed systems were further used for the removal of tetracycline under various process conditions. Optimum process conditions, enabling total removal of tetracycline from solutions at concentrations up to 1 mg/L, were found to be pH 5, temperature between 25 and 35 °C, and 1 h process duration. Due to the protective effect of the chitinous scaffolds and stabilization of the enzyme by multipoint attachment, the storage stability and thermal stability of the immobilized biomolecules were significantly improved as compared to the free enzyme. The produced biocatalytic systems also exhibited good reusability, as after 10 repeated uses they removed over 90% of tetracycline from solution. Finally, the immobilized laccase was used in a packed bed reactor for continuous removal of tetracycline, and enabled the removal of over 80% of the antibiotic after 24 h of continuous use.

scholarly journals Immobilization of invertase and glucoamylase on a macroporous copolymer of etyleneglycoldimethacrylate and glycidyl methacrylate and potential applications in biotechnology

2003 ◽  
Vol 57 (11) ◽  
pp. 536-542 ◽  
Author(s):  
Radivoje Prodanovic ◽  
Nenad Milosavic ◽  
Slobodan Jovanovic ◽  
Zoran Vujcic
Keyword(s):  
Specific Activity ◽  
Immobilized Enzymes ◽  
Packed Bed ◽  
Packed Bed Reactor ◽  
Specific Productivity ◽  
Glycoside Synthesis ◽  
Potential Applications ◽  
Almost All ◽  
Continuous Use ◽  
Macroporous Copolymer

The optimal conditions for the immobilization of invertase and glucoamylasewere found via their carbohydrate moiety on a macroporous copolymer of ehtyleneglycoldimethacry late and glycidylmethacrylate. Almost all of the added enzyme was bound to the polymer by increasing the time of incubation of the oxidized enzyme with polymer. A specific activity of 5500 U/g for invertase was obtained and 1100 U/g for glucoamylase. The specific productivity for invertase in a packed bed reactor was 3.5 kg/lh and for glucoamylase 1.9 kg/lh. During continuous use in a packed bed the reactor operational half life for invertase was 290 days, while no decrease in activity was observed for glucoamylase. In 50% (v/v) ethanol the immobilized enzymes were five to ten times more stable, and more than 200 times more stable in 25% (v/v) dioxane. The immobilized enzymes retained all activity in petroleum ether after 3 days of incubation. Because of their higher stability over native enzymes, and the large surface area of the polymer immobilized glucoamylase and invertase could be more useful for glycoside synthesis in non-aqueous solvents than native ones.

The Application of a Rotating Packed Bed Reactor for the Synthesis of High Viscosity Wax Ester

2021 ◽  
Vol 15 (3) ◽  
pp. 421-427
Author(s):  
Juntao Xu ◽  
Renwei Zhang ◽  
Changsheng Liu ◽  
Fang Wang ◽  
Kaili Nie ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Packed Bed ◽  
High Viscosity ◽  
Packed Bed Reactor ◽  
High Mass ◽  
Synthesis Process ◽  
Wax Ester ◽  
Process Conditions ◽  
Transfer Resistance ◽  
Rotating Packed Bed

Wax esters are high value-added products and widely used in a broad range of commercial fields. The enzymatic synthesis of wax ester from plant oil is more attractive than the traditional chemical method due to being environmental-friendly and limiting the use of hazardous chemicals. However, the high mass transfer resistance from the high viscous substrate leads to a low conversion and long reaction time in the continues stirred tank reactor (CSTR). The rotating packed bed reactor (RPBR) offers high mass transfer and can be used to enhance the enzymatic wax ester synthesis process. From the results, it could be concluded that the mass transfer was enhanced with the optimization of the centrifugal factor of the RPBR. Under the optimal process conditions, the wax ester yield of 96.4% was obtained after 4 hours reaction, and the half-life of the catalyst corresponded with 64 hours, while nine batches achieved of yields above 90%. The investigation proved that the RPBR is an attractive and effective reactor for heterogeneous bio-catalysis in high viscosity of 7.39~12.27 Cst at 40 °C.

Immobilized Whole Cells as Effective Catalysts for Chiral Alcohol Production

2009 ◽  
Vol 62 (9) ◽  
pp. 1034 ◽  
Author(s):  
Jeck Fei Ng ◽  
Stephan Jaenicke
Keyword(s):  
Flow Reactor ◽  
Batch Reactor ◽  
Enantiomeric Excess ◽  
Lactobacillus Brevis ◽  
Packed Bed ◽  
Alginate Beads ◽  
Packed Bed Reactor ◽  
Process Conditions ◽  
Alcohol Production ◽  
Whole Cells

Recombinant Escherichia coli overexpressing the gene LbADH, which encodes for an alcohol dehydrogenase from Lactobacillus brevis, was successfully transformed and cultured. The cells are able to catalyze the reduction of pro-chiral ketones, e.g. ethyl acetoacetate into R-(–)ethyl hydroxybutyrate (EHB) with high conversion and enantiomeric excess >99%. Immobilizing the whole cells in alginate beads leads to a catalyst with improved stability and ease of handling while maintaining the high activity of the free cells. The whole-cell catalyst was tested in a stirred batch reactor (CSTR) and in a continuously operated packed-bed reactor. An Mg2+ concentration of 2 mM was crucial for maintaining the activity of the biocatalyst. After a partial optimization of the process conditions, a productivity of 1.4 gEHB gwcw–1 h–1 could be maintained in a continuous flow reactor over a prolonged period of time.

scholarly journals Assessment of the Effect of Process Conditions and Material Characteristics of Alkali Metal Salt-Promoted MgO-Based Sorbents on Their CO2 Capture Performance

2021 ◽  
Author(s):  
Jian Chen ◽  
Lunbo Duan ◽  
Felix Donat ◽  
Christoph Müller
Keyword(s):  
Alkali Metal ◽  
Partial Pressure ◽  
Inductively Coupled Plasma ◽  
Metal Salt ◽  
Ambient Pressure ◽  
Alkali Metal Salt ◽  
Packed Bed ◽  
Packed Bed Reactor ◽  
Process Conditions ◽  
Capture Process

CO<sub>2</sub> capture using alkali metal salt (AMS)-promoted MgO-based sorbents at intermediate temperatures (300 – 500 °C) has gained increased interest recently. The prospects of such materials for CO<sub>2</sub> capture were assessed in this work. We investigated the most reactive MgO-based sorbents that have been reported in the literature, i.e., MgO promoted with a combination of various AMS (incl. NaNO<sub>3</sub>, LiNO<sub>3</sub>, K<sub>2</sub>CO<sub>3</sub> and Na<sub>2</sub>CO<sub>3</sub>), and examined how particle size (from powder to pelletized 500 μm particles) and reaction conditions (calcination/carbonation temperature, and partial pressure of CO<sub>2</sub>) affect the cyclic CO<sub>2</sub> uptake using a thermogravimetric analyzer (TGA) at ambient pressure. The TGA results showed that the CO<sub>2</sub> uptake of the sorbents decreased significantly after pelletization, losing 74 % of its initial capacity. However, the CO<sub>2</sub> uptake capacity of the pelletized sorbents continued to increase over 100 cycles and reached a value (~ 0.46 g<sub>CO2</sub>/g<sub>sorbent</sub>) close to that of the powdery sample (~ 0.53 g<sub>CO2</sub>/g<sub>sorbent</sub>). Analysis via X-ray diffraction (XRD), inductively coupled plasma optical emission spectroscopy (ICP-OES), scanning electron microscope (SEM) and N<sub>2</sub> physisorption suggests that the increase in CO<sub>2</sub> uptake was related to a change of the nature of the alkali species within the molten phase that is reflected by their re-crystallization behavior when cooling them down to room temperature, and appeared to be affected by the CO<sub>2</sub> partial pressure present during carbonation. Finally, the CO<sub>2</sub> capture performance of the best-performing sorbents was evaluated in a packed bed reactor, in order to assess whether the most reactive sorbents are capable of removing a significant amount of CO<sub>2</sub> from a gas stream at ambient pressure. The CO<sub>2</sub> uptake of the sorbents in the packed bed experiments was very close to that in the TGA experiments; however, the CO<sub>2</sub> capture efficiency was less than 10 %, which currently appears too low for an industrial post-combustion CO<sub>2</sub> capture process to be viable. New material developments should not only focus on improving the rate of formation of MgCO<sub>3</sub> from MgO, but also assess whether CO<sub>2</sub> removal with such sorbents is actually feasible.

scholarly journals Assessment of the Effect of Process Conditions and Material Characteristics of Alkali Metal Salt-Promoted MgO-Based Sorbents on Their CO2 Capture Performance

2021 ◽  
Author(s):  
Jian Chen ◽  
Lunbo Duan ◽  
Felix Donat ◽  
Christoph Müller
Keyword(s):  
Alkali Metal ◽  
Partial Pressure ◽  
Inductively Coupled Plasma ◽  
Metal Salt ◽  
Ambient Pressure ◽  
Alkali Metal Salt ◽  
Packed Bed ◽  
Packed Bed Reactor ◽  
Process Conditions ◽  
Capture Process

CO<sub>2</sub> capture using alkali metal salt (AMS)-promoted MgO-based sorbents at intermediate temperatures (300 – 500 °C) has gained increased interest recently. The prospects of such materials for CO<sub>2</sub> capture were assessed in this work. We investigated the most reactive MgO-based sorbents that have been reported in the literature, i.e., MgO promoted with a combination of various AMS (incl. NaNO<sub>3</sub>, LiNO<sub>3</sub>, K<sub>2</sub>CO<sub>3</sub> and Na<sub>2</sub>CO<sub>3</sub>), and examined how particle size (from powder to pelletized 500 μm particles) and reaction conditions (calcination/carbonation temperature, and partial pressure of CO<sub>2</sub>) affect the cyclic CO<sub>2</sub> uptake using a thermogravimetric analyzer (TGA) at ambient pressure. The TGA results showed that the CO<sub>2</sub> uptake of the sorbents decreased significantly after pelletization, losing 74 % of its initial capacity. However, the CO<sub>2</sub> uptake capacity of the pelletized sorbents continued to increase over 100 cycles and reached a value (~ 0.46 g<sub>CO2</sub>/g<sub>sorbent</sub>) close to that of the powdery sample (~ 0.53 g<sub>CO2</sub>/g<sub>sorbent</sub>). Analysis via X-ray diffraction (XRD), inductively coupled plasma optical emission spectroscopy (ICP-OES), scanning electron microscope (SEM) and N<sub>2</sub> physisorption suggests that the increase in CO<sub>2</sub> uptake was related to a change of the nature of the alkali species within the molten phase that is reflected by their re-crystallization behavior when cooling them down to room temperature, and appeared to be affected by the CO<sub>2</sub> partial pressure present during carbonation. Finally, the CO<sub>2</sub> capture performance of the best-performing sorbents was evaluated in a packed bed reactor, in order to assess whether the most reactive sorbents are capable of removing a significant amount of CO<sub>2</sub> from a gas stream at ambient pressure. The CO<sub>2</sub> uptake of the sorbents in the packed bed experiments was very close to that in the TGA experiments; however, the CO<sub>2</sub> capture efficiency was less than 10 %, which currently appears too low for an industrial post-combustion CO<sub>2</sub> capture process to be viable. New material developments should not only focus on improving the rate of formation of MgCO<sub>3</sub> from MgO, but also assess whether CO<sub>2</sub> removal with such sorbents is actually feasible.

Continuous production of a chiral amine in a packed bed reactor with co-immobilized amine dehydrogenase and formate dehydrogenase

2021 ◽  
Vol 407 ◽  
pp. 127065
Author(s):  
Robert D. Franklin ◽  
Joshua A. Whitley ◽  
Adam A. Caparco ◽  
Bettina R. Bommarius ◽  
Julie A. Champion ◽  
...  
Keyword(s):  
Formate Dehydrogenase ◽  
Continuous Production ◽  
Packed Bed ◽  
Packed Bed Reactor ◽  
Chiral Amine ◽  
Amine Dehydrogenase

scholarly journals First thermal studies on visible-light-switchable negative T-type photochromes of a nitrile-rich series

RSC Advances ◽  
2021 ◽  
Vol 11 (34) ◽  
pp. 21097-21103
Author(s):  
Mikhail Yu. Belikov ◽  
Mikhail Yu. Ievlev
Keyword(s):  
Thermal Stability ◽  
Visible Light ◽  
Temperature Effect ◽  
Thermal Studies ◽  
First Time ◽  
Thermal Stability Of

The temperature effect on the thermal stability of both the initial and photoinduced forms of nitrile-rich T-type photochromes was studied for the first time.

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