scholarly journals Kinetics and Thermodynamics of Thermal Inactivation of Cellulase from Salivary Glands of Macrotermes subhyalinus Little Soldier

2020 ◽  
Vol 9 (04) ◽  
pp. 13-20
Author(s):  
Fagbohoun Jean Bedel
Keyword(s):  
Salivary Glands ◽  
Thermal Inactivation ◽  
Kinetics And Thermodynamics ◽  
Macrotermes Subhyalinus

Kinetics and thermodynamics of thermal inactivation of partially purified bacteriocin from Pseudomonas aeroginosa

2020 ◽  
Author(s):  
P. Muthukumaran ◽  
R. Janani ◽  
S. Sivamani ◽  
N. Sivarajasekar ◽  
T. Pradeepika ◽  
...  
Keyword(s):  
Thermal Inactivation ◽  
Kinetics And Thermodynamics

scholarly journals Kinetic and Thermodynamic Analysis of Two Carboxymethylcellulases from Macrotermes subhyalinus Little Soldier

2017 ◽  
Vol 9 (4) ◽  
pp. 17
Author(s):  
Jean B. Fagbohoun ◽  
Mankambou J. Gnanwa ◽  
Fankroma M. T. Kone ◽  
S. Dabonne ◽  
Patrice L. Kouame
Keyword(s):  
Thermodynamic Parameters ◽  
Thermal Inactivation ◽  
Molecular Conformation ◽  
Residual Activity ◽  
Degradation Kinetic ◽  
Macrotermes Subhyalinus ◽  
Kinetic And Thermodynamic Parameters ◽  
Technology Applications ◽  
Kinetic And Thermodynamic Analysis ◽  
Increasing Temperature

Optimization of thermal processes relies on adequate degradation kinetic models to warrant food safety and quality. The knowledge on thermal inactivation of enzymes is necessary to allow their proper utilization in food industry and technology applications, enabling the reduction of heating times and optimization of heating temperatures. In this work, the kinetic of thermal inactivation was studied for the previously characterized carboxylmethylcellulases Ab-CX1 and Ab-CX2 from Macrotermes subhyalinus little soldier. Samples of carboxymethylcellulases were treated at different time-temperature combinations in the range of 5-60 min at 50-65°C and the kinetic and thermodynamic parameters for carboxymethylcellulases were calculated. Results showed that inactivation followed a first-order reaction with k-values between 0.0103 ± 0.0003 to 0.1217 ± 0.0005 and 0.0149 ± 0.0007 to 0.0416 ± 0.0003 min-1 for Ab-CX1 and Ab-CX2, respectively. At high temperatures, Ab-CX2 was less resistant, with a significant decrease in residual activity compared to Ab-CX1. The D- and k-values decreased and increased, respectively, with increasing temperature, indicating faster inactivation of carboxymethylcellulases. Activation energy (Ea) and Z-values were estimated to 76.74 ± 1.98 kJ.mol-1 and 24.21 ± 1.92 °C for Ab-CX1, 62.80 ± 2.05 kJ.mol-1 and 33.33 ± 2.78 °C for Ab-CX2. Thermodynamic parameters (ΔH#, ΔS# and ΔG#) were also calculated. The high value obtained for the variation in enthalpy of activation indicates that a high amount of energy is required to initiate denaturation, probably due to the molecular conformation of carboxymethylcellulases. All results suggest that both carboxymethylcellulases are relatively resistant to long heat treatments up to 50°C.

scholarly journals Kinetics and Thermodynamics of Thermal Inactivation of β-Galactosidase from Aspergillus oryzae

2018 ◽  
Vol 61 (0) ◽  
Author(s):  
Manuela Poletto Klein ◽  
Voltaire Sant’Ana ◽  
Plinho Francisco Hertz ◽  
Rafael Costa Rodrigues ◽  
Jorge Luiz Ninow
Keyword(s):  
Aspergillus Oryzae ◽  
Thermal Inactivation ◽  
Kinetics And Thermodynamics

scholarly journals Kinetics and thermodynamics of thermal inactivation for recombinant Escherichia coli cellulases, cel12B, cel8C, and polygalacturonase, peh28; biocatalysts for biofuel precursor production

2020 ◽  
Author(s):  
Eman Ibrahim ◽  
Ahmed Mahmoud ◽  
Kim D Jones ◽  
Keith E Taylor ◽  
Ebtesam N Hosseney ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Thermal Stability ◽  
Lignocellulosic Biomass ◽  
Thermal Inactivation ◽  
Biomass Conversion ◽  
Industrial Applications ◽  
Recombinant Escherichia Coli ◽  
Thermal Stabilities ◽  
Kinetics And Thermodynamics ◽  
Lignocellulosic Biomass Conversion

Abstract Lignocellulosic biomass conversion using cellulases/polygalacturonases is a process that can be progressively influenced by several determinants involved in cellulose microfibril degradation. This article focuses on the kinetics and thermodynamics of thermal inactivation of recombinant Escherichia coli cellulases, cel12B, cel8C and a polygalacturonase, peh 28, derived from Pectobacterium carotovorum sub sp. carotovorum. Several consensus motifs conferring the enzymes’ thermal stability in both cel12B and peh28 model structures have been detailed earlier, which were confirmed for the three enzymes through the current study of their thermal inactivation profiles over the 20–80°C range using the respective activities on carboxymethylcellulose and polygalacturonic acid. Kinetic constants and half-lives of thermal inactivation, inactivation energy, plus inactivation entropies, enthalpies and Gibbs free energies, revealed high stability, less conformational change and protein unfolding for cel12B and peh28 due to thermal denaturation compared to cel8C. The apparent thermal stability of peh28 and cel12B, along with their hydrolytic efficiency on a lignocellulosic biomass conversion as reported previously, makes these enzymes candidates for various industrial applications. Analysis of the Gibbs free energy values suggests that the thermal stabilities of cel12B and peh28 are entropy-controlled over the tested temperature range.

Kinetics and thermodynamics of thermal inactivation of the antimicrobial peptide cerein 8A

2009 ◽  
Vol 91 (2) ◽  
pp. 223-227 ◽  
Author(s):  
Rosiele Lappe ◽  
Florencia Cladera-Olivera ◽  
Ana Paula Melo Dominguez ◽  
Adriano Brandelli
Keyword(s):  
Antimicrobial Peptide ◽  
Thermal Inactivation ◽  
Kinetics And Thermodynamics

scholarly journals Studies on thermodynamics and kinetics of thermo-inactivation of xylanase from salivary glands of Macrotermes subhyalinus little soldier

2020 ◽  
Vol 12 (3) ◽  
pp. 130-138
Author(s):  
Fagbohoun Jean Bedel ◽  
Yapi Jocelyn Constant ◽  
Ya Kouame Claude ◽  
Disseka William Kwithony ◽  
Dabonne Soumaila ◽  
...  
Keyword(s):  
Salivary Glands ◽  
Macrotermes Subhyalinus ◽  
Thermodynamics And Kinetics ◽  
Kinetics Of

Ultrastructural Analysis of the Salivary Glands of Gromphadorhina Portentosa (Schaum)

1977 ◽  
Vol 35 ◽  
pp. 638-639
Author(s):  
P.J. Dailey
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Salivary Glands ◽  
Secretory Vesicles ◽  
The Past ◽  
Transmission Electron ◽  
Means Of Transmission ◽  
Gromphadorhina Portentosa ◽  
Scanning Electron ◽  
Topographical Relief

The structure of insect salivary glands has been extensively investigated during the past decade; however, none have attempted scanning electron microscopy (SEM) in ultrastructural examinations of these secretory organs. This study correlates fine structure by means of SEM cryofractography with that of thin-sectioned epoxy embedded material observed by means of transmission electron microscopy (TEM).Salivary glands of Gromphadorhina portentosa were excised and immediately submerged in cold (4°C) paraformaldehyde-glutaraldehyde fixative1 for 2 hr, washed and post-fixed in 1 per cent 0s04 in phosphosphate buffer (4°C for 2 hr). After ethanolic dehydration half of the samples were embedded in Epon 812 for TEM and half cryofractured and subsequently critical point dried for SEM. Dried specimens were mounted on aluminum stubs and coated with approximately 150 Å of gold in a cold sputtering apparatus.Figure 1 shows a cryofractured plane through a salivary acinus revealing topographical relief of secretory vesicles.

Sign in / Sign up

Export Citation Format

Share Document