scholarly journals Application of Immobilized Cholest-4-en-3-one Δ1-Dehydrogenase from Sterolibacterium denitrificans for Dehydrogenation of Steroids

2020 ◽  
Author(s):  
Mateusz Tataruch ◽  
Patrycja Wójcik ◽  
Agnieszka M. Wojtkiewicz ◽  
Katarzyna Zaczyk ◽  
Katarzyna Szymańska ◽  
...  
Keyword(s):  
Enzyme Immobilization ◽  
Electron Acceptor ◽  
Immobilized Enzyme ◽  
Specific Activity ◽  
Batch Reactor ◽  
Fed Batch ◽  
Immobilized Catalyst ◽  
Silica Supports ◽  
Dehydrogenase Enzyme ◽  
Final Yield

Cholest-4-en-3-one Δ1-dehydrogenase (AcmB) from Sterolibacterium denitrificans is successfully immobilized on 3-aminopropyltrimethoysilane functionalized MCF and SBA-15 silica supports using adsorption or covalently with glutaraldehyde or divinyl sulfone linkers. The best catalyst, AcmB on MCF linked covalently with glutaraldehyde, retains the specific activity of the homogenous enzyme while exhibiting a substantial increase of the operational stability. The immobilized enzyme was used continuously in the fed-batch reactor for 27 days, catalyzing 1,2-dehydrogenation of androst-4-en-3-one to androst-1,4-dien-3-one with a final yield of 29.9 mM (8.56 g/L) and 99% conversion. The possibility of reuse of the immobilized catalyst was also demonstrated and resulted with a doubling of the product amount compared to that in the reference homogenous reactor. Finally, it was shown that molecular oxygen from the air can efficiently be used as an electron acceptor either reoxidizing directly the enzyme or the reduced DCPIPH2. Keywords: 3-ketosteroid D1-dehydrogenase; KSTD; KSDH; AcmB; 1,2-dehydrogenation; cholest-4-en-3-one Δ1-dehydrogenase; enzyme immobilization, FAD-dependent enzymes; enzyme immobilization;

scholarly journals Application of Immobilized Cholest-4-en-3-one Δ1-Dehydrogenase from Sterolibacterium Denitrificans for Dehydrogenation of Steroids

Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1460
Author(s):  
Mateusz Tataruch ◽  
Patrycja Wójcik ◽  
Agnieszka M. Wojtkiewicz ◽  
Katarzyna Zaczyk ◽  
Katarzyna Szymańska ◽  
...  
Keyword(s):  
Molecular Oxygen ◽  
Electron Acceptor ◽  
Immobilized Enzyme ◽  
Specific Activity ◽  
Batch Reactor ◽  
Fed Batch ◽  
Santa Barbara ◽  
Immobilized Catalyst ◽  
Silica Supports ◽  
Final Yield

Cholest-4-en-3-one Δ1-dehydrogenase (AcmB) from Sterolibacterium denitrificans was successfully immobilized on 3-aminopropyltrimethoysilane functionalized mesoporous cellular foam (MCF) and Santa Barbara Amorphous (SBA-15) silica supports using adsorption or covalently with glutaraldehyde or divinyl sulfone linkers. The best catalyst, AcmB on MCF linked covalently with glutaraldehyde, retained the specific activity of the homogenous enzyme while exhibiting a substantial increase of the operational stability. The immobilized enzyme was used continuously in the fed-batch reactor for 27 days, catalyzing 1,2-dehydrogenation of androst-4-en-3-one to androst-1,4-dien-3-one with a final yield of 29.9 mM (8.56 g/L) and 99% conversion. The possibility of reuse of the immobilized catalyst was also demonstrated and resulted in a doubling of the product amount compared to that in the reference homogenous reactor. Finally, it was shown that molecular oxygen from the air can efficiently be used as an electron acceptor either reoxidizing directly the enzyme or the reduced 2,4-dichlorophenolindophenol (DCPIPH2).

scholarly journals Immobilization of chemically modified horse radish peroxidase within activated alginate beads

2014 ◽  
Vol 68 (1) ◽  
pp. 117-122 ◽  
Author(s):  
Dragica Spasojevic ◽  
Milos Prokopijevic ◽  
Olivera Prodanovic ◽  
Marilen Pirtea ◽  
Ksenija Radotic ◽  
...  
Keyword(s):  
Immobilized Enzyme ◽  
Specific Activity ◽  
Batch Reactor ◽  
Alginate Beads ◽  
Horse Radish Peroxidase ◽  
Original Activity ◽  
Chemically Modified ◽  
Ph Values ◽  
Repeated Use ◽  
Increased Activity

Immobilization of horse radish peroxidase (HRP) within alginate beads was improved by chemical modification of the enzyme and polysaccharide chains. HRP and alginate were oxidized by periodate and subsequently modified with ethylenediamine. Highest specific activity of 0.43 U/ml of gel and 81 % of bound enzyme activity was obtained using aminated HRP and alginate oxidized by periodate. Immobilized enzyme retained 75 % of original activity after 2 days of incubation in 80 % (v/v) dioxane and had increased activity at basic pH values compared to native enzyme. During repeated use in batch reactor for pyrogallol oxidation immobilized peroxidase retained 75 % of original activity.

On the Preparation of Bovine α-Thrombin

1978 ◽  
Vol 39 (01) ◽  
pp. 193-200 ◽  
Author(s):  
Erwin F Workman ◽  
Roger L Lundblad
Keyword(s):  
Immobilized Enzyme ◽  
Catalytic Properties ◽  
Specific Activity ◽  
Guanidine Hydrochloride ◽  
Low Molecular Weight ◽  
Reversible Process ◽  
Gel Beads ◽  
Tissue Thromboplastin ◽  
C 50 ◽  
Hydrolysis Of

SummaryAn improved method for the preparation of bovine α-thrombin is described. The procedure involves the activation of partially purified prothrombin with tissue thromboplastin followed by chromatography on Sulfopropyl-Sephadex C-50. The purified enzyme is homogeneous on polyacrylamide discontinuous gel electrophoresis and has a specific activity toward fibrinogen of 2,200–2,700 N.I.H. U/mg. Its stability on storage in liquid media is dependent on both ionic strenght and temperature. Increasing ionic strength and decreasing temperature result in optimal stability. The denaturation of α-thrombin by guanidine hydrochloride was found to be a partially reversible process with the renatured species possessing properties similar to “aged” thrombin. In addition, the catalytic properties of a-thrombin covalently attached to agarose gel beads were also examined. The activity of the immobilized enzyme toward fibrinogen was affected to a much greater extent than was the hydrolysis of low molecular weight, synthetic substrates.

Enrichment and characterization of an anaerobic methyl ethyl ketoxime degrading culture from an anoxic/anaerobic/aerobic activated sludge sequencing batch reactor

1998 ◽  
Vol 37 (4-5) ◽  
pp. 95-98 ◽  
Author(s):  
Nancy G. Love ◽  
Mary E. Rust ◽  
Kathy C. Terlesky
Keyword(s):  
Energy Source ◽  
Activated Sludge ◽  
Electron Acceptor ◽  
Sequencing Batch Reactor ◽  
Enrichment Culture ◽  
Batch Reactor ◽  
Nitrification Inhibitor ◽  
Time Frame ◽  
Methyl Ethyl

An anaerobic enrichment culture was developed from an anoxic/anaerobic/aerobic activated sludge sequencing batch reactor using methyl ethyl ketoxime (MEKO), a potent nitrification inhibitor, as the sole carbon and energy source in the absence of molecular oxygen and nitrate. The enrichment culture was gradually fed decreasing amounts of biogenic organic compounds and increasing concentrations of MEKO over 23 days until the cultures metabolized the oxime as the sole carbon source; the cultures were maintained for an additional 41 days on MEKO alone. Turbidity stabilized at approximately 100 mg/l total suspended solids. Growth on selective media plates confirmed that the microorganisms were utilizing the MEKO as the sole carbon and energy source. The time frame required for growth indicated that the kinetics for MEKO degradation are slow. A batch test indicated that dissolved organic carbon decreased at a rate comparable to MEKO consumption, while sulfate was not consumed. The nature of the electron acceptor in anaerobic MEKO metabolism is unclear, but it is hypothesized that the MEKO is hydrolyzed intracellularly to form methyl ethyl ketone and hydroxylamine which serve as electron donor and electron acceptor, respectively.

scholarly journals Optimal control of a fed-batch reactor with overflow metabolism

2020 ◽  
Vol 53 (2) ◽  
pp. 16820-16825
Author(s):  
Carlos Martínez ◽  
Jean-Luc Gouzé
Keyword(s):  
Optimal Control ◽  
Batch Reactor ◽  
Overflow Metabolism ◽  
Fed Batch

Thermodynamics-Based Nonlinear Control of a Three-Phase Slurry Catalytic Fed-Batch Reactor

2013 ◽  
Vol 21 (2) ◽  
pp. 360-371 ◽  
Author(s):  
S. Bahroun ◽  
F. Couenne ◽  
C. Jallut ◽  
C. Valentin
Keyword(s):  
Nonlinear Control ◽  
Batch Reactor ◽  
Fed Batch ◽  
Three Phase

Moving into Nanotechnology Roles to Mimic and Boost Enzyme Activity

2018 ◽  
pp. 421-440
Author(s):  
Maria Laura Soriano
Keyword(s):  
Enzyme Activity ◽  
Catalytic Activity ◽  
Enzyme Immobilization ◽  
Mesoporous Materials ◽  
Specific Activity ◽  
Artificial Enzymes ◽  
Catalytic Nanoparticles ◽  
Solid Liquid ◽  
By Products ◽  
Insight Into

A new tendency toward the design of artificial enzymes based on nanostructures (nanodots, nanofibers, mesoporous materials) has emerged. On one hand, nanotechnology bestows self-catalytic nanoparticles with a specific activity to achieve efficient reactions with low number of by-products. On other hand, the nanoparticles may behave as nanometric scaffolds for hosting enzymes, promoting their catalytic activity and stability. In this case, enzyme immobilization requires the preservation of the catalytic activity by preventing enzyme unfolding and avoiding its aggregation. These approaches render many other advantages like hosting/storing enzymes in nanotechnological solid, liquid, and gel-like media. This chapter focuses on the most up-to-date approaches to manipulate or mimic enzyme activity based on nanotechnology, and offers examples of their applications in the most promising fields. It also gives new insight into the creation of reusable nanotechnological tools for enzyme storage.

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