Operational stability of subtilisin CLECs in organic solvents in repeated batch and in continuous operation

Fernandes, João F. Amorim; McAlpine, Morven; Halling, Peter J.

doi:10.1016/j.bej.2005.01.014

Cited by 23 publications

(4 citation statements)

References 16 publications

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“…Cross‐linking causes low activity, poor reproducibility, low mechanical stability, and difficulties in handling. These issues are overcome by other protocols such as cross‐linked enzyme crystals (CLECs), cross‐linked enzyme aggregates (CLEAs) and combi‐CLEAs , , . CLECs are formed by crystallizing the enzyme from an aqueous buffer solution at an appropriate pH range and by treating with glutaraldehyde .…”

Section: Techniques For Enzyme Immobilizationmentioning

confidence: 99%

Immobilization of Lipases – A Review. Part I: Enzyme Immobilization

2019

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Free enzymes employed as biological catalysts have many advantages such as low reaction time, involving low energy and less waste output when compared to conventional chemical catalysts. However, commercial utilization of free enzymes is often hampered by the lack of operational stability, high cost, and non‐reusability. Immobilization of enzyme is an option to overcome these obstacles. Immobilized enzyme expresses stable performance in organic solvents even in adverse pH, which makes the biomolecules reusable and prosperous as a biological catalyst. Biological catalysis with immobilized enzymes is found to be an alternative method instead of chemical catalysis for chemical reactions in the foreseeable future. Sources of lipase, techniques in immobilization and cross‐linkers are dealt with in this paper.

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Section: Techniques For Enzyme Immobilizationmentioning

confidence: 99%

Immobilization of Lipases – A Review. Part I: Enzyme Immobilization

2019

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“…Enzymes are indeed unstable catalysts, but enzyme stabilization has been a major concern in biocatalysis and advances in the field are impressive [7,51] so that now enzymes stable enough even under stringent conditions are available. The use of nonconventional media is now well established for biocatalysis [72][73][74][75], and impressive advances have been obtained in conducting synthetic reactions both in organic solvent [76][77][78][79][80][81] and ionic liquid media [82][83][84][85]. Selectivity is maybe the most attractive property of an enzyme biocatalyst for performing organic synthesis: enzymes are highly regio-and enantioselective, which are very valuable attributes for the synthesis of pharmaceuticals and other biologically active compounds [52,53].…”

Section: Enzyme Biocatalysismentioning

confidence: 99%

“…Insolubilization by protein cross-linking is a promising technology to produce biocatalysts for synthesis. Cross-linked enzyme crystals obtained by cross-linking of previously crystallized enzyme protein are very stable and robust biocatalysts [14] that have been successfully applied to the synthesis of peptides [81,265], even though in this case the high cost of the biocatalyst is a drawback for its large-scale application. Their specific activity is very high since there is no inert matrix and the whole mass of biocatalyst is essentially pure enzyme protein.…”

Section: Enzymatic Synthesis Of Peptidesmentioning

confidence: 99%

Proteases as Powerful Catalysts for Organic Synthesis

Illanes

Guzmán

Barberis

2009

Amino Acids, Peptides and Proteins in Organic Chemistry

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“…This leads to high volumetric productivities and a finite control on the extension of the reaction itself and a simpli-418 fication of the downstream process. Furthermore, enzyme immobilization offers the possibility of recovering and reusing the biocatalyst (Fernandez et al, 2005). It offers numerous advantages such as the prevention of degradation of enzyme and substrate inhibition, which often is seen with free enzymes.…”

Section: Introductionmentioning

confidence: 99%

Preparation, characterization and optimization of cross-linked fructosyltransferase aggregates for the production of prebiotic fructooligosaccharides

Ademakinwa¹,

Ayinla²,

Omitogun³

et al. 2018

bta

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In this study, the preparation, characterization, and evaluation of the cross-linked enzyme aggregates (CLEAs) of fructosyltransferase isolated from the mutant-type Aureobasidium pullulans NAC8 for the production of fructooligosaccharides (FOS) with prebiotic properties were investigated. The reaction conditions were optimized statistically by using response surface methodology. CLEAs were characterized by using both photo-microscopy and scanning electron microscopy energy-dispersive X-ray spectroscopy (SEM-EDX). The secondary structure of the protein was predicted by using Fourier transform infrared spectroscopy (FTIR). FOSs produced as a result of the biotransformation of sucrose was quantified by using a chemometric analysis of FTIR spectral data. The prepared FOSs were investigated for the prebiotic effects under anaerobic conditions using a standard strain of Lactobacillus sp. Following were the statistically determined, optimum conditions for the production of FOSs: 5% (v/v) glutaraldehyde, pH 5.5, and a temperature of 32EC. The values of R 2 , F value, adjusted precision, and coefficient of variation were found to be 0.94, 11.50, 9.34, and 35.34%, respectively. Validation of the model resulted in the reusability of the CLEAs in six reaction cycles as it retained 70% of the residual activity. The SEM-EDX and photomicrographic analysis showed that the sizes of CLEAs varied, which ranged between 10 and 40 μm. Aggregation leads to the formation of a higher number of beta sheets in the CLEAs than that in the free enzyme. The total FOSs produced by the CLEAs was around 57% (w/v). A. pullulans FOS supplemented to the medium had a stimulatory effect on the growth of bi dobacteria compared with the control medium. The growth curves of Lactobacillus sp. reached the plateau phase after 24 h of cultivation with FOS. The CLEA of fructosyltransferase catalyzed the biocatalysis of sucrose to FOSs, a process with a biotechnological importance as prebiotics.

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Operational stability of subtilisin CLECs in organic solvents in repeated batch and in continuous operation

Cited by 23 publications

References 16 publications

Immobilization of Lipases – A Review. Part I: Enzyme Immobilization

Immobilization of Lipases – A Review. Part I: Enzyme Immobilization

Proteases as Powerful Catalysts for Organic Synthesis

Preparation, characterization and optimization of cross-linked fructosyltransferase aggregates for the production of prebiotic fructooligosaccharides

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