Recombinant family 3 carbohydrate-binding module as a new additive for enhanced enzymatic saccharification of whole slurry from autohydrolyzed Eucalyptus globulus wood
By-products resulting from lignocellulosics pretreatment affect the digestibility of resulting whole slurries, but this can be minimized by additives supplementation. In this work, a family 3 carbohydrate-binding module (CBM3), recombinantly produced from Escherichia coli, was used as additive in the enzymatic hydrolysis of the whole slurry from autohydrolyzed Eucalyptus globulus wood (EGW). At the higher dosage used (30 mg/gsolids), CBM3 led to an increase in glucose yield from 75 to 89%. A similar result was obtained for bovine serum albumin (BSA) (11% increase), which has a well-documented additive effect. CBM3 had no effect on the non-productive binding of enzymes, since it could not bind to EGW lignin, while it rapidly bound to cellulose, as shown by fluorescence microscopy. CBM3 is a valid additive for enhanced lignocellulosic saccharification and a valuable alternative to costly additives (e.g. polyethylene glycol) as it can be affordably produced from heterologous bacterium, thus contributing to more cost-efficient biomass valorization bioprocesses.
KeywordsRecombinant CBM3 Whole slurry Enzyme inhibition Lignin Enhanced saccharification
This work was developed under the strategic funding of UID/BIO/04469/2013 unit, COMPETE 2020 (POCI-01-0145-FEDER-006684) and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020—Programa Operacional Regional do Norte. The research leading to the reported results has received funding from Fundação para a Ciência e a Tecnologia (FCT) through the project MultiBiorefinery (POCI-01–0145-FEDER-016403) and through grants to C. Oliveira (SFRH/BPD/110640/2015) and D. Gomes (SFRH/BD/88623/2012).
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- Bayer EA, Kenig R, Lamed R (1983) Adherence of Clostridium thermocellum to cellulose. J Bacteriol 156:818–827Google Scholar
- Oliveira C, Sepúlveda G, Aguiar TQ, Gama FM, Domingues L (2015b) Modification of paper properties using carbohydrate-binding module 3 from the Clostridium thermocellum CipA scaffolding protein produced in Pichia pastoris: elucidation of the glycosylation effect. Cellulose 22:2755–2765CrossRefGoogle Scholar
- Tormo J, Lamed R, Chirino AJ, Morag E, Bayer EA, Shoham Y et al (1996) Crystal structure of a bacterial family-III cellulose-binding domain: a general mechanism for attachment to cellulose. EMBO J 15:5739–5751Google Scholar