scholarly journals Characterization of a cellobiose dehydrogenase from Humicola insolens

1998 ◽  
Vol 330 (1) ◽  
pp. 565-571 ◽  
Author(s):  
Charlotte SCHOU ◽  
H. Margrethe CHRISTENSEN ◽  
Martin SCHÜLEIN
Keyword(s):  
Methylene Blue ◽  
Phanerochaete Chrysosporium ◽  
Soft Rot ◽  
Electron Acceptors ◽  
Cellobiose Dehydrogenase ◽  
Humicola Insolens ◽  
Organic Electron ◽  
Anomeric Carbon ◽  
Prosthetic Groups

The major cellobiose dehydrogenase (oxidase) (CBDH) secreted by the soft-rot thermophilic fungus Humicola insolens during growth on cellulose has been isolated and purified. It was shown to be a haemoflavoprotein with a molecular weight of 92 kDa and a pI of 4.0, capable of oxidizing the anomeric carbon of cellobiose, soluble cellooligosaccharides, lactose, xylobiose and maltose. Possible electron acceptors are 2,6-dichlorophenol-indophenol (DCPIP), Methylene Blue, 3,5-di-t-butyl-1,2-benzoquinone, potassium ferricyanide, cytochrome c and molecular oxygen. The oxidation of the prosthetic groups by oxygen was monitored at 449 nm for the flavin group and at 562 nm for the haem group. The curves were very similar to those of the cellobiose dehydrogenase from Phanerochaete chrysosporium, suggesting a similar mechanism. The pH-optima for the oxidation varied remarkably depending on the electron acceptor. For the organic electron acceptors, the pH-optima ranged from pH 4 for Methylene Blue to pH 7 for DCPIP and the benzoquinone. In the case of the FeIII-containing electron acceptors, the enzyme displayed alkaline pH-optima, in contrast to the properties of cellobiose dehydrogenases from Phanerochaete chrysosporium and Myceliophthora (Sporotrichum) thermophila. The enzyme has optimal activity at 65 °C.

scholarly journals Characterization of a cellobiose dehydrogenase in the cellulolytic fungus Sporotrichum (Chrysosporium) thermophile

1982 ◽  
Vol 203 (1) ◽  
pp. 277-284 ◽  
Author(s):  
M R Coudray ◽  
G Canevascini ◽  
H Meier
Keyword(s):  
Methylene Blue ◽  
Extracellular Enzyme ◽  
Electron Acceptors ◽  
Cellobiose Dehydrogenase ◽  
Ph Optimum ◽  
Phenazine Methosulphate ◽  
Reduced Activity ◽  
Cellobionic Acid

An extracellular enzyme from culture filtrates of Sporotrichum (Chrysosporium) thermophile (A.T.C.C. 42 464) after growth on cellulose or cellobiose was shown to oxidize cellobiose to cellobionic acid in vitro. Lactose and cellodextrins were also efficiently oxidized, but the enzyme was not active against most mono- and di-saccharides. Several redox substances could act as electron acceptors, but molecular oxygen, tetrazolium salts and NAD(P) were not reduced. Activity was stimulated up to 2-fold in the presence of 0.05 M-Mg2+. The pH optimum of the enzymic reaction was acidic when the activity was tested with dichlorophenol-indophenol or Methylene Blue, but was neutral to alkaline for 3,5-di-t-butyl-1,2-benzoquinone or phenazine methosulphate as electron acceptors. As the enzyme was formed inductively in parallel with the endocellulase, its possible function in relation to cellulolysis is discussed.

Production and characterization of cellobiose dehydrogenase from Phanerochaete chrysosporium KCCM 60256 and its application for an enzymatic fuel cell

2016 ◽  
Vol 33 (12) ◽  
pp. 3434-3441 ◽  
Author(s):  
Han Suk Choi ◽  
Dong Sup Kim ◽  
Laxmi Prasad Thapa ◽  
Sang Jun Lee ◽  
Sung Bong Kim ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Phanerochaete Chrysosporium ◽  
Cellobiose Dehydrogenase ◽  
Enzymatic Fuel Cell

Characterization of Soft-rot-resistant Amorphophallus konjac and Preliminary Analysis of the Resistance Mechanism

2013 ◽  
Vol 48 (3) ◽  
pp. 295-302
Author(s):  
Lei Zhenzhen ◽  
Ye Jinglong ◽  
Cheng Haili ◽  
Chen Yun ◽  
Wang Huixing ◽  
...  
Keyword(s):  
Preliminary Analysis ◽  
Resistance Mechanism ◽  
Soft Rot ◽  
Amorphophallus Konjac

scholarly journals Synthesis and characterization of Cu(OH)2-NWs-PVA-AC Nano-composite and its use as an efficient adsorbent for removal of methylene blue

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sivarama Krishna Lakkaboyana ◽  
Khantong Soontarapa ◽  
Nabel Kalel Asmel ◽  
Vinay Kumar ◽  
Ravi Kumar Marella ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Kinetic Models ◽  
Batch Reactor ◽  
Maximum Adsorption Capacity ◽  
Nano Composite ◽  
Adsorption Processes ◽  
Intra Particle Diffusion ◽  
Short Time ◽  
Efficient Adsorbent

AbstractThe present study focused on the synthesis of copper hydroxide nanowires decorated on activated carbon (Cu(OH)2-NWs-PVA-AC). The obtained Cu(OH)2-NWs-PVA-AC Nano-composite was distinguished by XRD, SEM, EDX, BET, FTIR and XPS respectively. Besides, different variables such as solution pH, and initial dye concentration, contact time, and temperature were performed on the adsorption efficiency of MB in a small batch reactor. Further, the experimental results are analyzed by various kinetic models via PFO, PSO, intra-particle diffusion and Elovich models, and the results revealed that among the kinetic models, PSO shows more suitability. In addition, different adsorption isotherms were applied to the obtained experimental data and found that Langmuir–Freundlich and Langmuir isotherm were best fits with the maximum adsorption capacity of 139.9 and 107.6 mg/g, respectively. The Nano-composite has outstanding MB removal efficiency of 94–98.5% with a span of 10 min. and decent adsorption of about 98.5% at a pH of 10. Thermodynamic constants like Gibbs free energy, entropy, and enthalpy were analyzed from the temperature reliance. The results reveal the adsorption processes are spontaneous and exothermic in nature. The high negative value of ΔG° (− 44.11 to − 48.86 kJ/mol) and a low negative value of ΔH° (− 28.96 kJ/mol) show the feasibility and exothermic nature of the adsorption process. The synthesized dye was found to be an efficient adsorbent for the potential removal of cationic dye (methylene blue) from wastewater within a short time.

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