Purification and characterization of endoglucanase and exoglucanase components from Trichoderma viride

Kim, Dong Won; Jeong, Young Kyu; Jang, Young Hun; Lee, Jae Kuk

doi:10.1016/0922-338x(94)90005-1

Cited by 24 publications

(13 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The results showed also that the molecular weights of the 2 enzymes I, II were, 58 KDa and 34 KDa, respectively Fig (4). These findings are in agreement with other investigators that reported the presence of different isoenzymes with different molecular weights of CMCase produced by various microorganisms [112,113,114]. Our results are also in comparable to these obtained by Holt and Hartman (1994), they use a zymogram method to detect endoglucanases from Trichoderma reesei [115].…”

Section: Enzymes Molecular Weightssupporting

confidence: 83%

Fungal Biodegradation of Agro-Industrial Waste

Soliman¹,

El-Zawahry²,

El-Mougith³

2013

Cellulose - Biomass Conversion

View full text Add to dashboard Cite

Section: Enzymes Molecular Weightssupporting

confidence: 83%

Fungal Biodegradation of Agro-Industrial Waste

Soliman¹,

El-Zawahry²,

El-Mougith³

2013

Cellulose - Biomass Conversion

View full text Add to dashboard Cite

“…The equilibrium assumption is often justified by the observation that the time required for adsorbed cellulase to reach a constant value is short relative to the time required for hydrolysis. Most studies find that adsorbed cellulase reaches a constant value in Յ90 mins, and many studies have found Յ30 min to be sufficient (74,105,332,333,334,373,508,548,625,651,652), whereas complete hydrolysis of cellulose usually requires a day or more. The simplest representation of adsorption equilibrium is via an equilibrium constant, K d : …”

Section: Adsorptionmentioning

confidence: 99%

Microbial Cellulose Utilization: Fundamentals and Biotechnology

Lynd

Weimer

Zyl³

et al. 2002

Microbiol Mol Biol Rev

4,046

2,868

View full text Add to dashboard Cite

Fundamental features of microbial cellulose utilization are examined at successively higher levels of aggregation encompassing the structure and composition of cellulosic biomass, taxonomic diversity, cellulase enzyme systems, molecular biology of cellulase enzymes, physiology of cellulolytic microorganisms, ecological aspects of cellulase-degrading communities, and rate-limiting factors in nature. The methodological basis for studying microbial cellulose utilization is considered relative to quantification of cells and enzymes in the presence of solid substrates as well as apparatus and analysis for cellulose-grown continuous cultures. Quantitative description of cellulose hydrolysis is addressed with respect to adsorption of cellulase enzymes, rates of enzymatic hydrolysis, bioenergetics of microbial cellulose utilization, kinetics of microbial cellulose utilization, and contrasting features compared to soluble substrate kinetics. A biological perspective on processing cellulosic biomass is presented, including features of pretreated substrates and alternative process configurations. Organism development is considered for “consolidated bioprocessing” (CBP), in which the production of cellulolytic enzymes, hydrolysis of biomass, and fermentation of resulting sugars to desired products occur in one step. Two organism development strategies for CBP are examined: (i) improve product yield and tolerance in microorganisms able to utilize cellulose, or (ii) express a heterologous system for cellulose hydrolysis and utilization in microorganisms that exhibit high product yield and tolerance. A concluding discussion identifies unresolved issues pertaining to microbial cellulose utilization, suggests approaches by which such issues might be resolved, and contrasts a microbially oriented cellulose hydrolysis paradigm to the more conventional enzymatically oriented paradigm in both fundamental and applied contexts

show abstract

“…Product concentrations were calculated using glucose as a standard and activities were expressed as the unit U (μmol glucose equivalents /min). As CBHs and EGs show different product profiles [ 53 ], cellulase activities may be underestimated when glucose is used as a standard in reducing sugar assays [ 7 ]. Nevertheless, glucose is often applied [ 49 ] when analyzing relative changes in single cellulase activities.…”

Section: Methodsmentioning

confidence: 99%

Practical screening of purified cellobiohydrolases and endoglucanases with α-cellulose and specification of hydrodynamics

Jäger

Garschhammer

et al. 2010

Biotechnol Biofuels

View full text Add to dashboard Cite

BackgroundIt is important to generate biofuels and society must be weaned from its dependency on fossil fuels. In order to produce biofuels, lignocellulose is pretreated and the resulting cellulose is hydrolyzed by cellulases such as cellobiohydrolases (CBH) and endoglucanases (EG). Until now, the biofuel industry has usually applied impractical celluloses to screen for cellulases capable of degrading naturally occurring, insoluble cellulose. This study investigates how these cellulases adsorb and hydrolyze insoluble α-cellulose − considered to be a more practical substrate which mimics the alkaline-pretreated biomass used in biorefineries. Moreover, this study investigates how hydrodynamics affects cellulase adsorption and activity onto α-cellulose.ResultsFirst, the cellulases CBH I, CBH II, EG I and EG II were purified from Trichoderma reesei and CBH I and EG I were utilized in order to study and model the adsorption isotherms (Langmuir) and kinetics (pseudo-first-order). Second, the adsorption kinetics and cellulase activities were studied under different hydrodynamic conditions, including liquid mixing and particle suspension. Third, in order to compare α-cellulose with three typically used celluloses, the exact cellulase activities towards all four substrates were measured.It was found that, using α-cellulose, the adsorption models fitted to the experimental data and yielded parameters comparable to those for filter paper. Moreover, it was determined that higher shaking frequencies clearly improved the adsorption of cellulases onto α-cellulose and thus bolstered their activity. Complete suspension of α-cellulose particles was the optimal operating condition in order to ensure efficient cellulase adsorption and activity. Finally, all four purified cellulases displayed comparable activities only on insoluble α-cellulose.Conclusionsα-Cellulose is an excellent substrate to screen for CBHs and EGs. This current investigation shows in detail, for the first time, the adsorption of purified cellulases onto α-cellulose, the effect of hydrodynamics on cellulase adsorption and the correlation between the adsorption and the activity of cellulases at different hydrodynamic conditions. Complete suspension of the substrate has to be ensured in order to optimize the cellulase attack. In the future, screenings should be conducted with α-cellulose so that proper cellulases are selected to best hydrolyze the real alkaline-pretreated biomass used in biorefineries.

show abstract

Purification and characterization of endoglucanase and exoglucanase components from Trichoderma viride

Cited by 24 publications

References 21 publications

Fungal Biodegradation of Agro-Industrial Waste

Fungal Biodegradation of Agro-Industrial Waste

Microbial Cellulose Utilization: Fundamentals and Biotechnology

Practical screening of purified cellobiohydrolases and endoglucanases with α-cellulose and specification of hydrodynamics

Contact Info

Product

Resources

About