Kinetics of the hydrolysis of cellulose by β-1,4-glucan cellobiohydrolase of Trichoderma viride

1977 ◽  
Vol 55 (6) ◽  
pp. 644-650 ◽  
Author(s):  
R. James Maguire
Keyword(s):  
Time Course ◽  
Trichoderma Viride ◽  
Kinetic Equations ◽  
Gel Filtration ◽  
Product Inhibition ◽  
Cellulolytic Enzyme ◽  
Hydrolysis Of Cellulose ◽  
Ph Curve ◽  
Hydrolysis Of ◽  
Competitive Product

The cellulolytic enzyme β-1,4-glucan cellobiohydrolase (CBH) has been isolated from the crude mixture of cellulase enzymes of Trichoderma viride by gel filtration and ion-exchange methods, and some aspects of its kinetic behaviour have been examined. Studies of the initial rates of the CBH-catalyzed production of cellobiose from fibrous α-cellulose show that (i) the dissociation constant for cellobiose competitive product inhibition of the reaction is Ki = (1.13 ± 0.37) × 10−3 M, (ii) the adsorption of CBH on fibrous α-cellulose and its subsequent reaction conform to kinetic equations developed in conjunction with the Langmuir adsorption isotherm, (iii) the rate–pH curve has a maximum at pH 5.2 and decreases at higher and lower pH values, exhibiting enzyme pK values of 3.8 and 6.5, and (iv) the energy of activation of the overall reaction between 5 and 60 °C is 5.3 ± 0.3 kcal mol−1 at pH 5.2. Studies of the time course of the reaction over extended periods of time up to 40% hydrolysis of the cellulose show that (v) the data fit better to a competitive product inhibition model than to models of anticompetitive product inhibition or noncompetitive product inhibition.

Kinetics of the hydrolysis of cellobiose and p-nitrophenyl-β-D-glucoside by cellobiase of Trichoderma viride

1977 ◽  
Vol 55 (1) ◽  
pp. 19-26 ◽  
Author(s):  
R. James Maguire
Keyword(s):  
Steady State ◽  
Trichoderma Viride ◽  
Solution Temperature ◽  
Temperature Range ◽  
A Value ◽  
Steady State Kinetics ◽  
Decreasing Ph ◽  
Ph Curve ◽  
Kinetics Of ◽  
Hydrolysis Of

Cellobiase has been isolated from the crude cellulase mixture of enzymes of Trichoderma viride using column chromatographic and ion-exchange methods. The steady-state kinetics of the hydrolysis of cellobiose have been investigated as a function of cellobiose and glucose concentrations, pH of the solution, temperature, and dielectric constant, using isopropanol–buffer mixtures. The results show that (i) there is a marked activation of the reaction by initial glucose concentrations of 4 × 10−3 M to 9 × 10−2 M and strong inhibition of the reaction at higher initial concentrations, (ii) the log rate – pH curve has a maximum at pH 5.2 and enzyme pK values of 3.5 and 6.8, (iii) the energy of activation at pH 5.1 is 10.2 kcal mol−1 over the temperature range 5–56 °C, and (iv) the rate decreases from 0 to 20% (v/v) isopropanol.The hydrolysis by cellobiase (EC 3.2.1.21) of p-nitrophenyl-β-D-glucoside was examined by pre-steady-state methods in which [Formula: see text], and by steady-state methods as a function of pH and temperature. The results show (i) a value for k2 of 21 s−1 at pH 7.0 (where k2 is the rate constant for the second step in the assumed two-intermediate mechanism [Formula: see text]) (ii) a log rate–pH curve, significantly different from that for hydrolysis of cellobiose, in which the rate increases with decreasing pH below pH 4.5, is constant in the region pH 4.5–6, and decreases above pH 6 (exhibiting an enzyme pK value of 7.3), and (iii) an activation energy of 12.5 kcal mol−1 at pH 5.7 over the temperature range 10–60 °C.

scholarly journals Enzymatic Saccharification and Ethanol Production of Xylem from Purwodadi Botanical Garden Trees

2017 ◽  
Vol 4 (1) ◽  
pp. 117-120
Author(s):  
Mariko Sakata ◽  
Mito Tokue ◽  
Rumi Kaida ◽  
Teruaki Taji ◽  
Yoichi Sakata ◽  
...  
Keyword(s):  
Ethanol Production ◽  
Ball Mill ◽  
Trichoderma Viride ◽  
Enzymatic Saccharification ◽  
Botanical Garden ◽  
Palo Alto ◽  
Paraserianthes Falcataria ◽  
Enzymatic Hydrolysis Of Cellulose ◽  
Hydrolysis Of Cellulose ◽  
Hydrolysis Of

Recent studies have revealed that sengon (Paraserianthes falcataria) xylem consists of soft walls which are easily hydrolysable with a commercial cellulase preparation. We felt it important to determine the saccharification levels for fast-growing tropical trees, of which sengon, one of the fastest growing tree species in Indonesia, was used as the control wood species. The aim of this study was to screen and evaluate the xylem of Purwodadi Botanical Garden trees for saccharification in order to assess their potential usefulness in bioethanol production. Saccharification and fermentation were first examined in the xylem derived from the branches of 32 trees. The xylem was then milled into powder using a ball mill, and the powdered xylem was digested with a commercial cellulase preparation (Accelerase, Palo Alto, USA) derived from Trichoderma viride. The levels of enzymatic hydrolysis of cellulose and ethanol production were higher for Firmiana malayana and Pterocarpus indicus than for sengon. 

Regulation of cellulase from Ruminococcus

1972 ◽  
Vol 18 (3) ◽  
pp. 347-353 ◽  
Author(s):  
M. C. Fusee ◽  
J. M. Leatherwood
Keyword(s):  
Enzyme Activity ◽  
Cell Growth ◽  
Catabolite Repression ◽  
Specific Activity ◽  
Product Inhibition ◽  
Enzyme Synthesis ◽  
Energy Sources ◽  
Low Concentrations ◽  
Hydrolysis Of Cellulose ◽  
Hydrolysis Of

The regulation of cellulase was examined in Ruminococcus albus and R. flavefaciens. Hydrolysis of cellulose, as shown by the formation of clear zones around the colonies of bacteria grown in cellulose-agar roll tubes, was inhibited by moderate levels of cellobiose. An intermediate in the metabolism of cellobiose may be responsible for the inhibition since strains which can use either sucrose or lactose were similarly inhibited by these energy sources. The inhibition of cellulase was examined in relation to either repression of enzyme synthesis or product inhibition of the enzyme activity. There was no inhibition by cellobiose added either to the routine enzymatic assay or to assays using low concentrations of carboxymethylcellulose. A repression mechanism was indicated by the decrease in specific activity of cultures grown in higher concentrations of cellobiose. The specific activity was calculated as the enzymatic activity on carboxymethylcellulose with respect to cell growth. The mechanism of repression was not distinguished between the model proposed by Jacob and Monod and catabolite repression. The growth of R. albus cultured in cellobiose–cellulose liquid medium exhibited a diauxic pattern similar to that described by Monod.

scholarly journals Kinetic Modeling of Enzymatic Hydrolysis of Cellulosic Material

2021 ◽  
Author(s):  
Hanieh Shokrkar ◽  
Sirous Ebrahimi
Keyword(s):  
Enzymatic Hydrolysis ◽  
Time Course ◽  
Fermentable Sugars ◽  
Cellulosic Material ◽  
Cellulosic Materials ◽  
Enzymatic Hydrolysis Of Cellulose ◽  
Proposed Model ◽  
Hydrolysis Of Cellulose ◽  
Simulation Results ◽  
Hydrolysis Of

Abstract Development of a kinetic model for analysis of processes for fermentable sugars production is a significant challenging issue due to the complexity of the enzymatic hydrolysis of cellulose. This paper presents a useful mathematical model for simulation and evaluation of enzymatic hydrolysis of cellulosic material. The simulation results were compared with a set of experimental results reported in the literature, in order to validate the proposed model. A comparison was also made between the proposed model and another model previously described in the literature Numerical results indicate that the proposed model gives a more accurate prediction of time course production of glucose, cellobiose, and cellulose during enzymatic hydrolysis cellulosic materials.

scholarly journals Production of Sugar From Sweet Sorghum Stems with Hydrolysis Method Using Trichoderma viride

2021 ◽  
Vol 13 (1) ◽  
pp. 121-127
Author(s):  
Melycorianda Hubi Ndapamuri ◽  
Maria Marina Herawati ◽  
V Irene Meitiniarti
Keyword(s):  
Trichoderma Viride ◽  
Glucose Production ◽  
Cellulose Content ◽  
Hydrolysis Time ◽  
Glucose Yield ◽  
Hydrolysis Method ◽  
Hydrolysis Process ◽  
Hydrolysis Of Cellulose ◽  
Hydrolysis Of ◽  
Bagasse Waste

Sorghum stem bagasse waste is one of the materials with high cellulose content. It can be utilized in glucose production through enzymatic hydrolysis of cellulose by Trichoderma viride. This study aims to determine sorghum stem bagasse’s potential in producing glucose, assessing the time and concentration of sorghum stem bagasse in the hydrolysis process to produce glucose optimally and following SNI. Hydrolysis was carried out using a concentration of 5%, 8%, and 11% sorghum stem bagasse for 10, 15, and 20 days. The results showed that sorghum stem bagasse waste could produce glucose with an average glucose yield of 10.09% to 24.40 %. There is a tendency that increasing substrate concentration and hydrolysis time will increase the yield of liquid glucose. The treatment of 5% concentration of sorghum stem bagasse with a long hydrolysis time of 10 days can produce the highest liquid glucose, namely 24.40% with total dissolved solids of 7.40% Brix, the ash content of 0.26%, but 47.54% water content has not met SNI standards. 

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