Journal of Molecular Catalysis B: Enzymatic This is an RSS file. You can use it to subscribe to this data in your favourite RSS reader or to display this data on your own website or blog.

High-level secretory expression of Aspergillus exo-inulinase and its use in the preparation of fructose syrup from inulin
This study has fulfilled the scaled-up production of inulinase and facilitated its industrial application for enzymatic preparation of fructose from inulin. Graphical abstract (Source: Journal of Molecular Catalysis B: Enzymatic)
Source: Journal of Molecular Catalysis B: Enzymatic - September 30, 2017 Category: Biochemistry Source Type: research

The Candida rugosa lipase adsorbed onto titania as nano biocatalyst with improved thermostability and reuse potential in aqueous and organic media
Publication date: Available online 23 June 2017 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): Lidija T. Izrael Živković, Ljiljana S. Živković, Vladimir P. Beškoski, Kristina R. Gopčević, Bojan M. Jokić, Dragoslav S. Radosavljević, Ivanka M. Karadžić The immobilization of Candida rugosa lipase by adsorption was performed onto commercial titania powder (Degussa P25). The change of titania particles surface was diagnosed by means of FTIR and FESEM analysis, as well as by shift of zeta potential value towards that of lipase. A detailed study of the effect of immobilization on enzyme kinetic,...
Source: Journal of Molecular Catalysis B: Enzymatic - June 23, 2017 Category: Biochemistry Source Type: research

Covalent Immobilization of Cellulase in Application of Biotransformation of Ginsenoside Rb1
Publication date: Available online 11 May 2017 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): Ying Yuan, Xiaoning Luan, Mohamed E. Hassan, Deqiang Dou Cellulase was immobilized on the surface of carrageenan beads activated by using polyethyleneimine and glutaraldehyde, then immobilized cellulase was used to transform ginsenoside Rb1. In this work, we studied the functionalization of carrageenan with amine terminal functional group for the covalent immobilization of cellulase. The process of immobilization was performed by amination process on the surface of the carrageenan gel beads with polyethylenimi...
Source: Journal of Molecular Catalysis B: Enzymatic - May 11, 2017 Category: Biochemistry Source Type: research

A facile method to determine intrinsic kinetic parameters of ω-transaminase displaying substrate inhibition
Publication date: Available online 8 May 2017 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): Sang-Woo Han, Jong-Shik Shin It is usually time-consuming to determine intrinsic kinetic parameters of bisubstrate enzymes, especially when experimental kinetic data deviate from a linear Lineweaver-Burk plot due to complex inhibition patterns. A typical example is ω-transaminase (ω-TA) which is an industrially important enzyme for asymmetric synthesis of chiral amines. ω-TA catalyzes transfer of an amino group between a donor (D) and an acceptor (A) via a ping-pong bi-bi mechanism and often displays substrate...
Source: Journal of Molecular Catalysis B: Enzymatic - May 9, 2017 Category: Biochemistry Source Type: research

Microwave assisted enzymatic synthesis of biodiesel with waste cooking oil and dimethyl carbonate
Publication date: Available online 8 May 2017 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): D.C. Panadare, V.K. Rathod Biodiesel is considered to be a good alternative in renewable energy generation; therefore it is well studied throughout for its efficient, economic and greener production. Present study illustrated the use of waste cooking oil and dimethyl carbonate (DMC) as a reactants, enzyme as catalyst that facilitated the biodiesel production by providing low cost reactant, ecofriendly methodology and glycerol carbonate as marketable by-product. It also includes resolution to the problems conjured...
Source: Journal of Molecular Catalysis B: Enzymatic - May 9, 2017 Category: Biochemistry Source Type: research

A novel thermostable and halotolerant xylanase from Colletotrichum graminicola
Publication date: Available online 8 May 2017 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): Sibeli Carli, Luana Parras Meleiro, Jose Cesar Rosa, Luiz Alberto Beraldo Moraes, João Atílio Jorge, Douglas Chodi Masui, Rosa P.M. Furriel A novel endoxylanase from Colletotrichum graminicola (Excg1) was purified. Similar apparent molecular masses were estimated by gel filtration (17.3±1.9kDa) and sodium dodecyl sulfate polyacrylamide gel electrophoresis (20.0±2.4kDa), suggesting that Excg1 is monomeric. The enzyme showed good halotolerance, retaining about 85% and 50% of the control activity in the pre...
Source: Journal of Molecular Catalysis B: Enzymatic - May 9, 2017 Category: Biochemistry Source Type: research

Specificity of tyrosinase-catalyzed synthesis of theaflavins
This study kinetically characterized the mechanism of the enzymatic synthesis of theaflavins (TFs) from catechins by mushroom tyrosinase (EC 1.14.18.1). In reactions containing one of four catechins, (-)-epicatechin (EC), (-)-epigallocatechin (EGC), and their galloylated forms (ECg and EGCg), they were oxidized by tyrosinase with apparent K M values of 3.78mM, 5.55mM, 0.80mM, and 3.05mM, respectively, and with different consumption rates, of which EC was more than four-times higher than those of the others. In reactions with binary combinations of catechins with tyrosinase, the synthesis of TF1 from EC and EGC occurred mos...
Source: Journal of Molecular Catalysis B: Enzymatic - April 10, 2017 Category: Biochemistry Source Type: research

Mono- and heterofunctionalized silica magnetic microparticles (SMMPs) as new carriers for immobilization of lipases
In this study, mono- and heterofunctionalized silica magnetic microparticles (SMMPs) were synthetized for immobilization of lipase B from Candida antarctica (CALB). The SMMPs were prepared in a micro-emulsion system containing sodium silicate and superparamagnetic iron oxide nanoparticles, followed by chemical modification with octyl groups and octyl plus aldehyde groups. These supports allowed the immobilization of CALB by hydrophobic adsorption or hydrophobic/covalent linkages, achieving immobilization yield of 88% and recovered activities of 128% and 59%, respectively. The performance of the magnetic biocatalysts was ev...
Source: Journal of Molecular Catalysis B: Enzymatic - April 10, 2017 Category: Biochemistry Source Type: research

Xylanase 30 A from Clostridium thermocellum functions as a glucuronoxylan xylanohydrolase
In this report, we show that CtXyn30A is a GlcA dependent endoxylanase with no significant activity on arabinoxylans, an anticipated result given the amino acid conservation within the substrate binding cleft. Graphical abstract (Source: Journal of Molecular Catalysis B: Enzymatic)
Source: Journal of Molecular Catalysis B: Enzymatic - April 3, 2017 Category: Biochemistry Source Type: research

Comparative analysis of point mutations on protein COOH terminal near surface and its hydrophobic core provide insights on thermostability of Bacillus Lipase LipJ
Publication date: Available online 2 April 2017 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): Shelly Goomber, Nisha Chopra, Gursimran Kaur Bedi, Jagdeep Kaur Amino acid composition, protein conformation, weak interactions are some of the factors determining protein stability. Two point mutants of Bacillus LipJ (Ala81Tyr and Asn166Tyr) were designed and generated for comparison. Residue Ala81 targeted for substitution was buried in protein core with 0% accessibility. On other hand, residue Asn166 at protein COOH terminal was predicted to be located within αF helix near surface. Point variants Ala81Tyr...
Source: Journal of Molecular Catalysis B: Enzymatic - April 2, 2017 Category: Biochemistry Source Type: research

Catalase Immobilization on Amino-activated Fe3O4@SiO2 Nanoparticles: Loading Density Affected Activity Recovery of Catalase
Publication date: Available online 27 March 2017 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): Liang Wang, Guo Chen, Jun Zhao, Ning Cai A blackberry-shaped Fe3O4@SiO2 nanoparticles were prepared, characterized and applied in covalently binding catalase. The enzyme loading decreased with the increase of pH, however, the activity recovery increased simultaneously. To elucidate the influence factor of the activity recovery, the enzyme loading was further regulated by changing the initial free enzyme content. The relationship between enzyme loading and activity recovery showed the consistent trend, whethe...
Source: Journal of Molecular Catalysis B: Enzymatic - March 28, 2017 Category: Biochemistry Source Type: research

Xylanase 30A from Clostridium thermocellum functions as a glucuronoxylan xylanohydrolase
In this report, we show that CtXyn30A is a GlcA dependent endoxylanase with no significant activity on arabinoxylans, an anticipated result given the amino acid conservation within the substrate binding cleft. Graphical abstract (Source: Journal of Molecular Catalysis B: Enzymatic)
Source: Journal of Molecular Catalysis B: Enzymatic - March 28, 2017 Category: Biochemistry Source Type: research

Enhanced catalytic efficiency of nitrilase from Acidovorax facilis 72W and application in bioconversion of 3-cyanopyridine to nicotinic acid
In this study, the catalytic efficiency using NitA from Acidovorax facilis 72W for nicotinic acid (NA) production was investigated and further improved by site-directed mutagenesis. Results showed that the specific activity of mutated NitA-C2 (F168V-S192F) towards 3-cyanopyridine increased 5-fold to 35Umg−1 protein. Further characterization of the biochemical properties of both nitrilases showed the optimal pH and temperature were 6.0-8.0 and 60°C, respectively, whereas the pH and thermal stability of NitA-C2 were decreased. Finally, whole cell catalysis was adopted for NA production and a 100% conversion yield was achi...
Source: Journal of Molecular Catalysis B: Enzymatic - March 28, 2017 Category: Biochemistry Source Type: research

Antioxidant and antibacterial activity of fatty acid vanillyl ester produced by Proteus vulgaris K80 lipase-mediated transesterification
In this study, we carried out a Proteus vulgaris K80 lipase-mediated transesterification reaction using VA and menhaden oil (MO) to produce fatty acid vanillyl ester (FAVE) and achieved a conversion yield of 75.3%. FAVE purified by prep-HPLC showed 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and the scavenging activity increased significantly in non-polar solvent. FAVE also inhibited the formation of conjugated diene and triene in MO-in-water emulsion stabilized by Tween 20. Furthermore, FAVE showed evident antibacterial activity against typical food spoilage bacteria by interacting with cell membrane and rel...
Source: Journal of Molecular Catalysis B: Enzymatic - March 28, 2017 Category: Biochemistry Source Type: research

Activity of Candida rugosa lipase for synthesis of hexyl octoate under high hydrostatic pressure and the mechanism of this reaction
Publication date: Available online 24 March 2017 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): Gang Chen, Huanmei Du, Bo Jiang, Ming Miao, Biao Feng Candida rugosa lipase (CRL) in organic solvent was treated under high hydrostatic pressure. The lipase was activated at pressure below 300MPa while deactivated at pressure over 400MPa. Especially, the esterification activity of CRL was enhanced by 90% at 300MPa but reduced to 85% at 500MPa. Consistent with the activation of CRL under 300MPa, the ester yield and initial reaction rate was also enhanced significantly at this pressure incubated for 45min. In...
Source: Journal of Molecular Catalysis B: Enzymatic - March 24, 2017 Category: Biochemistry Source Type: research