초록
<P><B>Abstract</B></P> <P>Protein heterologous production offers viable opportunities to tailor laccase properties to specific industrial needs. The high redox potential laccase POXA1b from <I>Pleurotus ostreatus</I> was chosen as case study of marketable enzyme, due to its desirable properties in terms of activity/stability profile, and already assessed applicability.</P> <P>POXA1b was heterologously produced in <I>Pichia pastoris</I> by investigating the effect of inducible and constitutive expression systems on both the yield and the cost of its production. System performances were first assessed in shaken-flasks and then scaled-up in bioreactor. The production level obtained in the inducible system is 42U/mL, while the activity value achieved with the constitutive one is 60U/mL, the highest obtained in constitutive systems so far. The economic feasibility of recombinant laccase production was simulated, describing the case of an Italian small-medium enterprise. Two scenarios were evaluated: Scenario (I) production based on methanol inducible system; Scenario (II) production based on the constitutive system, fed with glycerol. At all the scales the glycerol-based fermentation is more economic than the methanol-based one. The price forecast for rPOXA1b production is 0.34€kU<SUP>−1</SUP> for glycerol-based process, and is very competitive with the current price of commercial laccase.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Recombinant production of a high redox potential laccase. </LI> <LI> Economical analysis of inducible and constitutive systems for laccase production. </LI> <LI> The price forecast for POXA1b production is around 10<SUP>−4</SUP> €U<SUP>−1</SUP>. </LI> </UL> </P>