Discovery of new levansucrase enzymes with interesting properties and improved catalytic activity to produce levan and fructooligosaccharides

2019 ◽  
Vol 9 (11) ◽  
pp. 2931-2944 ◽  
Author(s):  
Andrea Hill ◽  
Lily Chen ◽  
Aline Mariage ◽  
Jean-Louis Petit ◽  
Véronique de Berardinis ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Catalytic Activity ◽  
Acceptor Specificity ◽  
P Mining

Mining for new levansucrase enzymes with high levan production, transfructosylating activity, and thermal stability and studying their kinetics and acceptor specificity.

Catalytic activity of niobium oxynitride and carbide I. Preparation, characterization and thermal stability of finely divided niobium oxynitrides

1994 ◽  
Vol 119 (2) ◽  
pp. 223-240 ◽  
Author(s):  
Hak Soo Kim ◽  
Chae Ho Shin ◽  
Guy Bugli ◽  
Monique Bureau-Tardy ◽  
Gerald Djega-Mariadassou
Keyword(s):  
Thermal Stability ◽  
Catalytic Activity ◽  
Thermal Stability Of

scholarly journals Influence of Water Activity on Protease Adsorbed on Biochar in Organic Solvents

2017 ◽  
Vol 6 (4) ◽  
pp. 96 ◽  
Author(s):  
Hidetaka Noritomi ◽  
Jumpei Nishigami ◽  
Nobuyuki Endo ◽  
Satoru Kato ◽  
Katsumi Uchiyama
Keyword(s):  
Thermal Stability ◽  
Catalytic Activity ◽  
Organic Solvents ◽  
Water Activity ◽  
Initial Rate ◽  
Butyl Ester ◽  
Nitrogen Atmosphere ◽  
Bamboo Charcoal ◽  
Influence Of Water ◽  
Hydrolysis Of

We have found that the organic solvent-resistance of Alpha-chymotrypsin (Alpha-CT) is enhanced by adsorbing Alpha-CT onto bamboo charcoal powder (BCP), which is obtained by pyrolyzing bamboo waste under nitrogen atmosphere, and is markedly dependent on the thermodynamic water activity (aw) in organic solvents. When BCP-adsorbed　Alpha-CT was immersed in acetonitrile at an appropriate water activity, it effectively enhanced the transesterification of N-acetyl-L-tyrosine ethyl ester (N-Ac-Tyr-OEt) with n-butanol (BuOH) to produce N-acetyl-L-tyrosine butyl ester (N-Ac-Tyr-OBu), compared to the hydrolysis of N-Ac-Tyr-OEt with water to give N-acetyl-L-tyrosine (N-Ac-Tyr-OH). When the water activity was 0.28, the initial rate of transesterification catalyzed by BCP-adsorbed Alpha-CT was about sixty times greater than that catalyzed by free Alpha-CT. Regarding the reaction selectivity which is defined as a ratio of the initial rate of transesterification to that of hydrolysis, BCP-adsorbed α-CT was much superior to free Alpha-CT. The catalytic activity of BCP-adsorbed Alpha-CT was markedly dependent on the reaction temperature. Furthermore, concerning the thermal stability at 50 oC, the half-life of BCP-adsorbed Alpha-CT exhibited 3.8-fold, compared to that of free Alpha-CT.

Enhanced catalytic activity with high thermal stability based on multiple Au cores in the interior of mesoporous Si–Al shells

RSC Advances ◽  
2015 ◽  
Vol 5 (60) ◽  
pp. 48187-48193 ◽  
Author(s):  
Yiwei Zhang ◽  
Sanming Xiang ◽  
Yuming Zhou ◽  
Yuanmei Xu ◽  
Zewu Zhang ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Catalytic Activity ◽  
High Activity ◽  
High Thermal Stability

Mesoporous Si–Al/Au nanocatalysts were synthesized by combining the advantage of good permeability from mesoporous Si–Al shells and the high activity upon multiple Au cores.

scholarly journals The Sintering of Au Nanoparticles on Flat {100}, {111} and Zigzagged {111}-Nanofacetted Structures of Ceria and Its Influence on Catalytic Activity in CO Oxidation and CO PROX

2020 ◽  
Author(s):  
O. S. Bezkrovnyi ◽  
P. Kraszkiewicz ◽  
W. Mista ◽  
L. Kepinski
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Catalytic Activity ◽  
Beneficial Effect ◽  
Co Oxidation ◽  
Au Nanoparticles ◽  
Ceria Support ◽  
Ceria Catalysts ◽  
Thermal Stability Of

Abstract The thermal stability of Au nanoparticles on ceria support of various morphology (nanocubes, nanooctahedra, and {111}-nanofacetted nanocubes) in oxidizing and reducing atmospheres was investigated by electron microscopy. A beneficial effect of the reconstruction of edges of ceria nanocubes into zigzagged {111}-nanofacetted structures on the inhibition of sintering of Au nanoparticles was shown. The influence of different morphology of Au particles on various ceria supports on the reducibility and catalytic activity in CO oxidation, and CO PROX of Au/ceria catalysts was also investigated and discussed. It was shown, that ceria nanocubes with flat {110} terminated edges are more suitable as a support for Au nanoparticles, used to catalyze CO oxidation, than zigzagged {111}- nanofacetted structures. Graphic Abstract

Catalytic Activity and Thermal Stability of Arc Plasma Deposited Pt Nano-Particles on CeO2–Al2O3

2015 ◽  
Vol 15 (11) ◽  
pp. 8494-8501 ◽  
Author(s):  
Young Eun Jeong ◽  
Pullur Anil Kumar ◽  
Hee Lack Choi ◽  
Kwan-Young Lee ◽  
Heon Phil Ha
Keyword(s):  
Thermal Stability ◽  
Catalytic Activity ◽  
Nano Particles ◽  
Arc Plasma ◽  
Thermal Stability Of
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