Enzymatic kinetic of cellulose hydrolysis
- Cite this article as:
- Bezerra, R.M.F. & Dias, A.A. Appl Biochem Biotechnol (2005) 126: 49. doi:10.1007/s12010-005-0005-5
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The ethanol effect on the Trichoderma reesei cellulases was studied to quantify and clarify this inhibition type. To determine inhibition parameters of crude cellulase and purified exoglucanase Cel7A, integrated Michaelis-Menten equations were used assuming the presence of two inhibitors: cellobiose as the reaction product and ethanol as a possible bioproduct of cellulose fermentation.
It was found that hydrolysis of cellulose by crude enzyme follows a model that considers noncompetitive inhibition by ethanol, whereas Cel7A is very slightly competitively inhibited. Crude cellulase is much more inhibited (Kiul=Kicl=151.9 mM) than exoglucanase Cel7A (Kicl=1.6 × 1015 mM). Also, calculated inhibition constants showed that cellobiose inhibition is more potent than ethanol inhibition both for the crude enzyme as well as exoglucanase Cel7A.