Short CommunicationProduction of fiberboard using corn stalk pretreated with white-rot fungus Trametes hirsute by hot pressing without adhesive
Highlights
► MOR and MOE of fiberboard were significantly increased by bio-pretreatment. ► Mechanical property increasing reasons were investigated by instrumental analysis. ► Bio-pretreatment could make the fiberboard product more environmentally friendly.
Introduction
Field crop residues like cereal straw, corn stalk, flax straw, corn cob, rice husk, represent a potentially valuable source of fiber which can be used as a supplement or substitute for wood fiber in the manufacture of composites such as fiberboard (Hornsby et al., 1997, Panthapulakkal et al., 2006, Yang et al., 2004). Currently, such composites are produced with formaldehyde-based adhesives regardless of the fiber source. These adhesives are made from non-renewable resources, can cause formaldehyde emissions, and make it difficult to recycle the final product (Gonzalez-Garcia et al., 2011).
White-rot fungi efficiently degrade and mineralize lignin into CO2 and H2O, as they are able to secrete lignin-degrading enzymes including laccase (EC 1.10.3.2), lignin peroxidase (EC 1.11.1.14), and manganese peroxidase (EC 1.11.1.13). Since laccase catalyzes one-electron oxidations that generate free radicals that can react with other phenolic components, cross-linking can occur (Sakaguchi et al., 2007), and laccase can be used to produce lignin-based adhesives or fiberboards made with laccase-oxidized wood fibers (Felby et al., 2002, Gonzalez-Garcia et al., 2011). However, laccase is expensive and it remains to be determined if fiberboards made with laccase-treated fibers achieve a hardness required by national standards.
In this study, white-rot fungus Trametes hirsute was used to pre-treat corn stalk to investigate the relationship between bio-pretreatment and mechanical properties of the fiberboard by hot pressing without adhesive. For studying how bio-pretreatment influenced the mechanical properties of the fiberboard, the changes of bio-pretreated corn stalk were analyzed by Fourier transform infra-red spectroscopy and X-ray diffraction.
Section snippets
Strain and the cultivation
T. hirsute was isolated at the Key Laboratory of Molecular Biophysics of MOE, Huazhong University of Science and Technology, and identified at the China General Microbiological Culture Collection Center in Beijing, China. The organism was maintained on potato extract agar at 5 °C. Two discs cut from actively growing cultures on potato extract agar plates were used to inoculate 100 ml of 20% potato extract and 2% glucose medium in a 250-ml round flask, and the culture was grown at 25 °C for 2 days
Mechanical properties of fiberboard
Modulus of rupture (MOR) and modulus of elasticity (MOE) are key mechanical properties of fiberboard (Teixeira and Moslemi, 2001). As shown in Fig. 1, the MOR and MOE of un-pretreated fiberboard (0 d in Fig. 1) were only 0.77 ± 0.10 MPa and 46.57 ± 11 MPa, respectively. With increasing bio-pretreatment time, the MOR and MOE of the fiberboard increased and reached the highest when corn stalk was pretreated for 21 days (3.40- and 8.87-fold increase, respectively over untreated corn stalk) with T. hirsute
Conclusions
The mechanical properties of the corn-stalk-based fiberboard without adhesive were improved by pretreatment with the white-rot fungus T. hirsute. Pretreatment increased the mechanical properties of the fiberboard since it increased the number of hydroxyl groups, crystallinity, and polysaccharide and laccase contents of the corn stalks. Large-scale product the fiberboard without adhesive will require optimization of hot pressing, fermentation, and post-processing.
Acknowledgements
The authors gratefully acknowledge the valuable assistance of the Analytical and Testing Center in Huazhong University of Science and Technology for the technology of FTIR and X-ray diffraction analysis.
References (15)
- et al.
Laccase is essential for lignin degradation by the white-rot fungus Pycnoporus cinnabarinus
FEBS Lett.
(1997) - et al.
Pilot-scale production of fiberboards made by laccase oxidized wood fibers: board properties and evidence for cross-linking of lignin
Enzyme Microb. Technol.
(2002) - et al.
Environmental assessment of green hardboard production coupled with a laccase activated system
J. Clean. Prod.
(2011) - et al.
Effect of structural features on enzyme digestibility of corn stover
Bioresour. Technol.
(2006) - et al.
Preparation and characterization of wheat straw fibers for reinforcing application in injection molded thermoplastic composites
Bioresour. Technol.
(2006) - et al.
Non-destructive NIR FT Raman analysis of plants
J. Mol. Struct.
(1999) - et al.
Assessing modulus of elasticity of wood-fiber cement (WFC) sheets using nondestructive evaluation (NDE)
Bioresour. Technol.
(2001)
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