scholarly journals Modulation of the Biocatalytic Properties of a Novel Lipase from Psychrophilic Serratia sp. (USBA-GBX-513) by Different Immobilization Strategies

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1574
Author(s):  
Mónica Ruiz ◽  
Esteban Plata ◽  
John J. Castillo ◽  
Claudia C. Ortiz ◽  
Gina López ◽  
...  

In this work, the effect of different immobilization procedures on the properties of a lipase obtained from the extremophilic microorganism Serratia sp. USBA-GBX-513, which was isolated from Paramo soils of Los Nevados National Natural Park (Colombia), is reported. Different Shepharose beads were used: octyl-(OC), octyl-glyoxyl-(OC-GLX), cyanogen bromide (BrCN)-, and Q-Sepharose. The performance of the different immobilized extremophile lipase from Serratia (ESL) was compared with that of the lipase B from Candida antarctica (CALB). In all immobilization tests, hyperactivation of ESL was observed. The highest hyperactivation (10.3) was obtained by immobilization on the OC support. Subsequently, the thermal stability at pH 5, 7, and 9 and the stability in the presence of 50% (v/v) acetonitrile, 50% dioxane, and 50% tetrahydrofuran solvents at pH 7 and 40 °C were evaluated. ESL immobilized on octyl-Sepharose was the most stable biocatalyst at 90 °C and pH 9, while the most stable preparation at pH 5 was ESL immobilized on OC-GLX-Sepharose supports. Finally, in the presence of 50% (v/v) tetrahydrofuran (THF) or dioxane at 40 °C, ESL immobilized on OC-Sepharose was the most stable biocatalyst, while the immobilized preparation of ESL on Q-Sepharose was the most stable one in 40% (v/v) acetonitrile.

2009 ◽  
Vol 62 (8) ◽  
pp. 799 ◽  
Author(s):  
Nemanja Miletić ◽  
Katja Loos

Candida antarctica lipase B, Cal-B, was (i) chemically modified with various epoxides, or (ii) cross-linked with various diepoxides in order to improve enzyme activity and thermal stability. Changed enzyme structure was confirmed by kinetic resolution of p-nitrophenol acetate with methanol and determination of the kinetic parameters. Thermal stability measurements were carried out for each Cal-B derivative, proving that Cal-B modified with 1,2-epoxypropane and 1,2-epoxypentane, and cross-linked with 1,2,7,8-diepoxyoctane and 1,2,9,10-diepoxydecane showed higher stability than soluble enzyme. The influence of the length of the epoxide arm in the modification process, as well as the length of the spacer arm in the cross-linking process, on the final enzyme preparation properties was investigated. The amount of epoxides and diepoxides used for structural rearrangement played an important role in the derivatives’ characteristics. The influence of the precipitant used and the presence of additives, such as surfactant or crown-ether, during modification and cross-linking processes was also revealed.


2015 ◽  
Vol 4 (2) ◽  
pp. 87-99 ◽  
Author(s):  
Valerio Ferrario ◽  
Cynthia Ebert ◽  
Patrizia Nitti ◽  
Giuliana Pitacco ◽  
Lucia Gardossi

2018 ◽  
Vol 129 ◽  
pp. 12-24 ◽  
Author(s):  
Nathalia Saraiva Rios ◽  
Maisa Pessoa Pinheiro ◽  
Magno Luís Bezerra Lima ◽  
Denise Maria Guimarães Freire ◽  
Ivanildo José da Silva ◽  
...  

2012 ◽  
Vol 531-532 ◽  
pp. 8-12
Author(s):  
M.A. Sai Balaji ◽  
K. Kalaichelvan

Organic fibres (Kevlar/ Arbocel / Acrylic) have good thermal stability, higher surface area and bulk density. The optimization of organic fibres percentage for thermal behaviour is considered using TGA. The temperature raise during brake application will be between 150-4000 C and this temperature zone is very critical to determine the fade characteristics during friction testing. Hence, three different friction composites are developed with the same formulation varying only the Kevlar, Arbocel and Acrylic fibres which are compensated by the inert filler namely the barites and are designated as NA01, NA02 and NA03 respectively. After the fabrication, the TGA test reveals that the composite NA03 has minimum weight loss. The friction coefficient test rig is then used to test the friction material as per SAE J661a standards. The results prove that the brake pad with minimum weight loss during TGA has higher friction stability. Thus, we can correlate the thermal stability with the stability of friction.


2002 ◽  
Vol 80 (6) ◽  
pp. 565-570 ◽  
Author(s):  
Szilvia Gedey ◽  
Arto Liljeblad ◽  
László Lázár ◽  
Ferenc Fülöp ◽  
Liisa T Kanerva

The Candida antarctica lipase B-catalyzed reactions of five β-amino esters with neat butyl butanoate and with 2,2,2-trifluoroethyl butanoate in diisopropyl ether were studied, as were the reactions of the same β-amino esters and their N-butanamides with neat butanol. The possibility for sequential resolution, where the amino and ester functions of the substrate both react with an achiral butanoate, became less likely with increasing size of the substrate from ethyl 3-aminobutanoate (1a) to pentanoate (1b) or larger. On the other hand, the alcoholyses of N-acylated β-amino esters successfully proceeded in butanol with E > 100. Gram-scale resolution of the N-butanoylated 1a was performed to demonstrate the usefulness of the method. Key words: lipase, interesterification, acylation, alcoholysis, resolution, β-amino esters.


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