engleski

Oxidation of coniferyl alcohol catalyzed by laccases from Trametes versicolor

Oxidation of coniferyl alcohol by commercial laccase and raw laccase preparation produced by submerged cultivation of Trametes versicolor in medium containing waste from paper industry was investigated. Both laccases gave 100 % conversions of up to 0.8 mmol dm-3 of coniferyl alcohol. Regarding investigated reaction conditions, pH of 6.6 and temperature of 35 ºC were found to be optimal for coniferyl alcohol oxidation catalyzed by commercial laccase. Based on the initial reaction rate measurements, Michaelis-Menten kinetic parameters for commercial laccase were evaluated in an aqueous media (Vm = 4.387 U mg-1, = 0.025 mmol dm-3), as well as in 1:1 (v/v) methanol : phosphate buffer mixture (Vm = 0.979 U mg-1, = 0.019 mmol dm-3). On the other hand, kinetic studies of coniferyl alcohol oxidation catalyzed by raw laccase revealed substrate inhibition. A mathematical model of batch process comprising of double-substrate Michaelis-Menten kinetics with oxygen as a second substrate was developed and verified in experiments with or without additional aeration.

coniferyl alcohol; laccase; Trametes versicolor; kinetics models

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