Izvorni znanstveni članak
Effect of the Degree of Polymerization of Inulin on the Rate of Hydrolysis Using Immobilized Inulinase
Stefano Curcio
orcid.org/0000-0002-8497-7470
; Laboratory of Transport Phenomena and Biotechnology, Department of Informatics, Modeling, Electronics and Systems Engineering (D.I.M.E.S.), University of Calabria, Ponte P. Bucci, cubo 39/c, IT-87036 Rende, Italy
Emanuele Ricca
; Laboratory of Transport Phenomena and Biotechnology, Department of Informatics, Modeling, Electronics and Systems Engineering (D.I.M.E.S.), University of Calabria, Ponte P. Bucci, cubo 39/c, IT-87036 Rende, Italy
Vincenza Calabrò
; Laboratory of Transport Phenomena and Biotechnology, Department of Informatics, Modeling, Electronics and Systems Engineering (D.I.M.E.S.), University of Calabria, Ponte P. Bucci, cubo 39/c, IT-87036 Rende, Italy
Gabriele Iorio
; Laboratory of Transport Phenomena and Biotechnology, Department of Informatics, Modeling, Electronics and Systems Engineering (D.I.M.E.S.), University of Calabria, Ponte P. Bucci, cubo 39/c, IT-87036 Rende, Italy
Sažetak
The present paper addresses two crucial features in the industrial development of fructose production by enzymatic hydrolysis of inulin: the use of immobilized biocatalyst in the hydrolysis of crude extracts of chicory roots and the evaluation of the effect of degree of polymerization of inulin on the overall reaction rate. The immobilized biocatalyst consisted of inulinase covalently bound to Sepabeads® supports. It was demonstrated that its catalytic activity towards crude inulin extract (real substrate) was much higher than that exhibited towards pure inulin (synthetic solution). Experiments revealed that, in applications of practical interest with real substrate, the activity of immobilized enzyme was as high as 63 % of that of free enzyme in homogeneous solution. This certainly was a driving force to potential industrial application of this immobilized enzyme preparation. Therefore, the effect of pure and crude substrates on the kinetics of the reaction catalysed by the immobilized enzyme was investigated. The kinetic analysis revealed a Michaelis-Menten dependence of the reaction rate on substrate concentration for both pure (high molecular
mass) and crude (low molecular mass) inulin. Interesting results were derived from the comparison of Km and vmax values in the two cases. In particular, it was found that increasing degree of polymerization of the substrate caused vmax decrease and Km increase. After evaluation of mass transport effects, this was mainly associated with a different substrate/ enzyme affinity when exploiting inulin characterized by different (low or high) degree of polymerization.
Ključne riječi
immobilized enzyme; kinetic analysis; degree of polymerization; inulinase; fructose syrup
Hrčak ID:
126178
URI
Datum izdavanja:
15.9.2014.
Posjeta: 1.739 *