Isotherms for adsorption of cellobiohydrolase I and II from Trichoderma reesei on microcrystalline cellulose

Journal Article · Tue Apr 01 00:00:00 EST 1997 · Applied Biochemistry and Biotechnology

DOI:https://doi.org/10.1007/BF02788806· OSTI ID:588708

Medve, J; Tjerneld, F ^[1]; Stahlberg, J ^[2]

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1. Univ. of Lund (Sweden)
2. Univ. of Uppsala (Sweden)

Adsorption to microcrystalline cellulose (Avicel) of pure cellobiohydrolase I and II (CBH I and CBH II) from Trichoderma reesei has been studied. Adsorption isotherms of the enzymes were measured at 4{degree}C using CBH I and CBH II alone and in reconstituted equimolar mixtures. Several models (Langmuir, Freundlich, Temkin, Jovanovic) were tested to describe the experimental adsorption isotherms. The isotherms did not follow the basic (one site) Langmuir equation that has often been used to describe adsorption isotherms of cellulases; correlation coefficients (R{sup 2}) were only 0.926 and 0.947, for CBH I and II, respectively. The experimental isotherms were best described by a model of Langmuir type with two adsorption sites and by a combined Langmuir-Freundlich model (analogous to the Hill equation); using these models the correlation coefficients were in most cases higher than 0.995. Apparent binding parameters derived from the two sites Langmuir model indicated stronger binding of CBH II compared to CBH I; the distribution coefficients were 20.7 and 3.7 L/g for the two enzymes, respectively. The binding capacity was higher for CBH I than for CBH II. The isotherms when analyzed with the combined model indicated presence of unequal binding sites on cellulose and/or negative cooperativity in the binding of the enzyme molecules. 39 refs., 3 figs., 3 tabs.

• Sponsoring Organization: USDOE
• OSTI ID: 588708
• Journal Information: Applied Biochemistry and Biotechnology, Vol. 66, Issue 1; Other Information: PBD: Apr 1997
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
55 BIOLOGY AND MEDICINE
BASIC STUDIES
ADSORPTION
ADSORPTION ISOTHERMS
CELLULOSE
ENZYMES
HILL EQUATION
MIXTURES
TRICHODERMA
CELLULASE
BIOCONVERSION
BIOCHEMISTRY
ENZYMATIC HYDROLYSIS
MOLECULAR STRUCTURE
COST
MATHEMATICAL MODELS
HEMICELLULOSE