Inactivating effects of lignin-derived compounds released during lignocellulosic biomass pretreatment on the endo-glucanase catalyzed hydrolysis of carboxymethylcellulose: A study in continuous stirred ultrafiltration-membrane reactor.
This study focusses on the reversible/irreversible damage that selected phenolic compounds, released during steam-explosion pretreatment, mandatory for cellulose accessibility, causes on both stability and activity of a commercial cellulase (half-life=173h) during carboxymethyl-cellulose hydrolysis. Long-term experiments performed in continuous stirred UF-membrane bioreactors, operating at steady-state regime, in controlled operational conditions, allowed evaluating the inactivation-constant in the phenol presence (kd1) and after its removal (kd2) from the reactor feed. p-Hydroxybenzoic acid (1 and 2g L(-1)) are the extreme limits in the inactivating effect with enzyme half-lives 99.02 and 14.15h, respectively. The inactivation reversibility was assessed for vanillic acid, p-hydroxybenzoic acid, syringaldehyde, p-coumaric acid, being kd1>kd2. p-Hydroxybenzaldehyde and protocatechuic acid irreversibly affected cellulase stability increasing its inactivation with kd2>kd1. p-Hydroxybenzaldehyde, 1g L(-1), syringaldehyde, and vanillin, at 2gL(-1), had similar kd1÷kd2.
Department of Industrial and Information Engineering and Economics, University of l'Aquila, via Giovanni Gronchi n.18-Nucleo industriale di Pile, 67100 L'Aquila, Italy. Electronic address: maria.cantarella@univaq.it.
Maria
M
Cantarella
Department of Industrial and Information Engineering and Economics, University of l'Aquila, via Giovanni Gronchi n.18-Nucleo industriale di Pile, 67100 L'Aquila, Italy.
Claudia
C
Mucciante
Department of Civil and Mechanical Engineering, University of Cassino and of Lazio Meridionale, via Di Biasio 43, 03043 Cassino (FR), Italy.
Laura
L
Cantarella
D055162:Biocatalysis / Q000187:drug effects; D018533:Biomass; D019149:Bioreactors; D002266:Carboxymethylcellulose Sodium / Q000378:metabolism*; D002480:Cellulase / Q000378:metabolism*; D004795:Enzyme Stability / Q000187:drug effects; D006868:Hydrolysis / Q000187:drug effects; D007700:Kinetics; D008031:Lignin / Q000378:metabolism*; D008567:Membranes, Artificial; D008970:Molecular Weight; D010636:Phenols / Q000494:pharmacology; D012212:Rheology / Q000187:drug effects; D013997:Time Factors; D014462:Ultrafiltration / Q000295:instrumentation*
D008567:Membranes, Artificial; D010636:Phenols; C036909:lignocellulose; D008031:Lignin; D002480:Cellulase; D002266:Carboxymethylcellulose Sodium
Continuous stirred UF-membrane bioreactor; Glucanase activity for CMC hydrolysis; Inactivating effect; Inactivation constant; Lignin-derived compounds